Running a Home-Office Through a UPS

mwagner_00 asks: "After spending lots of money and time, I now have an office in my home. My wife and I both have computers (mine is a high powered gaming rig), and I also have a workbench where I work on other people's PCs. I have a web/email server as well. I would like to protect the investment by running the room's power through a UPS. I have a APC 3000NET that my workplace was going to throw out. The only thing it needs is a good set of batteries. Has anyone tried something like this before? Basically I want to find the breaker for the room, and after the breaker, run the power through the UPS and back out to the room. Is the UPS that I have sufficient to run a whole small office?"

Comments

My recommendation

[RingDev]

A surge strip and extention cord for the work bench. If you are going to try to patch into the house wiring you're going to want a certified electritian, and depending on housing codes in your area, you may need a certificate from the building inspector.

Much easier to mount the UPS under the work bench and to run an extention cord/surge strip to the other PCs. You don't want to have anything running off the protector you don't need. Things like speakers, printers, PDA chargers, etc.

-Rick

Re:My recommendation

[Anonymous Coward]

I would suggest that anything connected to the computer at least be run through a surge protector - so you won't have any surges finding their way into your computer through them.

But the only thing you should have running on the uninterruptable power supply itself is the computer and monitor - the essentials only. You want to be able to save documents and safely turn the machine off should the mains power fail (or have PowerChute do it). Do not make the solution more complicated than the problem.

Re:My recommendation

[lopgok]

I have a modest bunch of computers in my office. Each one has a separate UPS. The 500-900VA ones are pretty cheap. Each computer powers down the UPS when the UPS gets low on power. I also have a separate UPS for my screen, because it used be a 19" CRT and suck power. You want to only plug the stuff that really needs uninterruptable power. If you use a power strip and a cheaper UPS, make sure the power strip doesn't have a surge supressor built into it, as the 'modified sine waves' will toast the surge supressor. I also have some line-interactive sine synthesizing 1000va UPS's that I bought surplus. Not the cheapo square wave or 'modified sine wave' UPS's. All reasonably sized UPS that I have seen 1000-3000VA run on 48v. That means four 12v batteries. They tend to run a bit hot and loud. Not a problem in a datacenter, but perhaps overkill for a home office. If anyone wants a 1000va sine synthesizing UPS that has failed for some reason, I have one for sale. No schematic. Made by powerware.

18 amps

[MobyDisk]

The specs say 2250 watts. 2250 watts divided by 120 volts = 18.75 amps. So, in theory, you could hook this to a circuit with an 18 amp fuse or breaker.

Of course, doing this is surely a crazy violation of electrical codes. Would it be that hard just to plug the computers into the UPS? It has plenty of outlets, it really looks like that is how it was intended. Wiring it right to the electrical box might get you some geek points, but you might also become a Darwin awards nominee.

I doubt it is worth it.

Re:18 amps

[Bastian]

On top of that, wiring the entire room up to the UPS would result in a crazy waste of the UPS's power.

If the power suddenly goes out, do you really want the lights in the room simultaneously drawing extra power from the UPS and hiding from you a pretty good clue that the power just went out?

This is surely not the way a UPS meant to be used. I've certainly never seen one hooked up this way.

Re:18 amps

[ForestGrump]

What I do is keep one light plugged into the UPS. All the other lights aren't. So if the power goes out, I'll know but still be able to see.

Re:18 amps

[wimbor]

Where I live it is illegal to connect your lights and power outlets on the same circuit. You need a seperate breaker for the lights and one for other appliances...

Re:18 amps

[M1FCJ]

What you want is a couple of flourescent lamps with an emergency supply, a small 12V battery which keeps the lamp on after the power goes out. This way you don't have to heat a huge filament using precious watts and turning it into a heater plus a small amount of light. These fixtures are a requirement in real office places, providing you with light for emergencies.

Re:18 amps

[Webmoth]

I have installed a few of these units at customers' sites. In the U.S. they require a dedicated 120V 30A circuit -- something you most likely will NOT have in your house; such a circuit would need to be installed by a qualified person.

While you could replace the plug on the cord to fit in your present outlet, you must consider the following:

1) Your existing circuit will either be rated 15A or 20A

2) There will be other things on the circuit "upstream" of the UPS, and therefore the available capacity for the UPS will be diminished

3) The existing outlets will most likely be 15A rated outlets (in the U.S. it's legal to wire a 15A outlet in a 20A ciruit). It's generally NOT acceptable to wire a 15A plug on a device which can draw more than 15A.

4) The continuous load on a circuit may not exceed 80% of the circuit's rating. On a 120V 20A circuit, this would be 18A, or 2160VA/2160W. Your UPS will have two ratings: VA and W. (In this case, 3000VA and 2250W.) When sizing the circuit, you must consider the LARGER of these two numbers, which results in the need for a 30A circuit.

Specific loads....

[karnal]

First off, you do not want to put the UPS in like that for the whole room. I'd say if you really want to put it in in this fashion, make dedicated circuits (like in some datacenters) beside the regular circuits that are UPS'd. That way you have a choice of outlets... Anyways...

You kind of need to specify the kind of loads you'd like to put on the UPS. What you'd need to do is look at how many machines, how many monitors, etc.

For instance, you do NOT want to put lighting (flourescent or otherwise) on a UPS.

I have an older APC 900 that has external modules that I can add battery packs to, if I want a long runtime.

I'm rambling, but a 3000 will power a lot of equipment, for a short amount of time. The batteries for the "higher numbered" UPS's seem to be pretty small, so you don't get much runtime out of them. For a quick-and-dirty of how long, get an estimated wattage you're going to draw from the UPS. Then, take battery voltage, multiply by number of batteries in the UPS, then multiply by the AH of ONE battery. That gives you the watt-hours of your UPS.

If you're going to draw 450 watts from a UPS and the batteries add up to 450 or so, then you'll get about 1 hour - 20%.... Efficiency losses run about 20% (I'm guessing here)...

Anywho. My 900 runs a file server, switch, cable modem, sipura phone box, and the gateway for about 2 hours. It only has one battery pack, but my battery packs are 4x(12v*18AH), which is around 864Watt Hours. So I'm probably drawing 400 watts continuously through the UPS....

Re:Specific loads....

[Trepalium]

The other reason you don't want to wire the entire room is that if you have a laser printer, it cannot be on the UPS. Laser printers have a tendancy to need a large amount of power in a very short time which can easily overload most UPSs. Any other high-draw device can also cause problems (fridge, microwave, air conditioner, etc).

In addition, there a a number of devices that do not like the modified sine wave output from UPSs. Many RF based devices (radio, television, satellite, etc) may experience interference, some electric motors may run poorly, and battery chargers may cause damage to the batteries being charged.

Frankly, it's probably easier to decide what to include on the UPS, than it is to decide how to exclude certain devices.

Re:Specific loads....

[Anonymous Coward]

Should have looked at the specs for the specific unit he mentioned...
For instance, you do NOT want to put lighting (flourescent or otherwise) on a UPS.
The unit (APC 3000NET) is a pure sine-wave output with 5% max distortion at full load. This will not bother flourescent lights at all.
Old flourescent ballasts will often fail from overheating due to increased losses from the high harmonics from square-wave or step-sine wave outputs, but not this unit. Incidentally, these same losses are the reason AC motors are not recommended on sqare-wave or step-sine outputs.
Newer electronic flourescent ballasts are less affected by the loss issue, but often behave badly beacuse the switching circuits can be affected by the higher harmonics in square-wave or step-sine outputs.
As for incandescent bulbs, they seem to care not at all. I have read about decreased lifetime from mechanical shock on square wave output UPS's but personal experience shows little, if any, decrease in lifetime.

Re:Specific loads....

[guardian-ct]

You do want at least one low-powered light on your UPS, unless you enjoy typing by flashlight. You can get a lot done with a 13-watt flourescent. Don't run your 500 watt halogen lights off it though. UPSes aren't usually designed to run heating equipment like that.

Re:Specific loads....

[guardian-ct]

It all depends on how good your UPS is, how much higher the UPS rating is than the normal load, etc. Some laser printers these days are low enough power draw, that running them on a UPS is merely a drain on battery life, instead of an overload. Doesn't mean it's a good idea though, since you should probably be safely shutting down your systems instead of printing out the power-outage report forms.

Re:My humble suggestion...

[KILNA]

A UPS only outputs power to the protected connections, the only person getting shocked would be the OP if he forgot to turn off the UPS before doing electrical work in the single room he was planning on giving backup power to.

UPS

[HotNeedleOfInquiry]

First of all, don't muck with your house wiring. It would be far better to reorganize your room around the UPS than to change the wiring inside your breaker box. It's unlikely that it would be legal and if there ever was an issue concerning fires or insurance, your ass would be in a sling.

As to batteries, I have an old surplus 700 watt APC UPS that I run 4 servers and a couple of switches on. The batteries were dead when I got it and I jury-rigged 2 garden tractor batteries in series to it. It works perfectly, but your mileage may vary. The UPS manufacturers generally *do not* want you to do this, so do it at your own risk.

Re:UPS

[Trepalium]

I hope you jerry-rigged those batteries outside the UPS case and the room is well ventilated. Given the fact that unsealed lead-acid batteries have a tendency to produce hydrogen, there could be an explosion danger with doing something like that.

Re:UPS

[rcw-work]

As to batteries, I have an old surplus 700 watt APC UPS that I run 4 servers and a couple of switches on. The batteries were dead when I got it and I jury-rigged 2 garden tractor batteries in series to it. It works perfectly, but your mileage may vary. The UPS manufacturers generally *do not* want you to do this, so do it at your own risk.

While you may have had good luck with this, I'd encourage others not to hook oversized batteries to their UPS. The rationale is that, by massively expanding the battery capacity, you are increasing the amount of time that the inverter may run. Most inverters in cheap UPS's (such as a typical 700-watt APC) are not designed to dissipate the heat they produce at full load for anything longer than the designed runtime. If you let them run long enough they will get hot enough to fry themselves and possibly catch on fire.

If your UPS has connectors for external batteries, chances are its invertor was designed for an expanded battery capacity. If it doesn't, chances are it wasn't. If it doesn't have fans, that's another clue.

Since you need an electrician

[sharkey]

Why don't you ask him? Or do you already have the 30-amp circuit with a NEMA L5-30P outlet?

Basically, you'd want to pull the feed for this room off the breaker entirely, and terminate it with a grounded outlet next to the breaker. It should be a simple matter to get or make a heady-duty male-to-male power cord. Put the UPS by the breaker box and you're done.

On the flip side, this likely violates a number of building and electric codes where you live. Probably not the safest setup either.

Re:Since you need an electrician

[andrewla]

A male to male power cord is a Darwin award device.
It goes beyond stupid and into a criminal offence.

Re:Since you need an electrician

[Anonymous Coward]

Yep. These are generally called 'suicide cords' for a reason. If you try to backfeed your house with a generator plugged in with a male-to-male cord, you stand agood chance of killing yourself when the power is restored (by a 'dancing' or exploding generator), or killing a lineman who's working on your line (by backfeeding through the transformer on the pole).

Re:Since you need an electrician

[pyite]

It often gets the name "suicide cable" by those familiar with such things.

UPS for the computer, generator for the room

[Anonymous Coward]

Use a UPS to keep the computer running when the power goes off, but get a small generator to power the whole room. That will keep you up and running a lot longer than a battery can. You can get a generator that will power one room for under $1000.

Code is the key here.

[Myself]

Don't even think about doing this without talking to your city's electrical inspector. She will, of course, laugh you out of her office.

The UPS is an appliance, not a fixture. It has to be separable from the building wiring by a plug. It doesn't carry the appropriate ratings and classifications for being wired-in. Use the appropriate output cords and power strips.

That being said, you might want to do some research into generator transfer switches, and the idea that some of the house's loads would be on a separate panel that gets backup power.

Re:Code is the key here.

[adolf]

Seperable by a plug, eh?

So: Break the feed heading into the server room. Terminate one side in a male plug, and the other side in a female. Plug the UPS into this pair of connectors.

Done*.

And then, if required need to disconnect the UPS appliance, simply do so, much as you would any other appliance.

(*Variations might (and probably should) include using double-insulated stranded wire, installing a panel directly after said male plug with fusing/breakers appropriate for the wire and connectors, and also some sane restriction on the length of said male plug's attached cord.)

It is safe: If someone does something stupid, the panel's fuse pops before the UPS does. No smoke. No fire.

It is reliable: If the UPS pops on its own (which they seem to do with alarming regularity, even if they're "good" ones), it will be easy to bypass - just plug the male end into the female socket, without a UPS in between.

What's the big deal? That the output of the battery-backup appliance happens to go through the wall into a series of permanently-mounted outlets? So what?

Would you rather it be attached to a snakepit of inadequate extension cords, as is often the case when someone tries to a room worth of gear from one temporarily-installed UPS?

Re:Code is the key here.

[the_xaqster]

In the UK, if you permanantly wire _anything_ in, you need to get it certified by a qualified electrician. Mounting plug sockets in the wall, even if they has a plug on the end, counts as permanent. This has been a requirment since 1st Jan 2005.

Electricians can charge what they like for this service, so it may be cheaper to have a sparky do this for you. Get some quotes first.

Re:Code is the key here.

[David Horn]

If you want to wire it like this, my advice would be to obtain a separate consumer unit and treat the output of the UPS into it as you would the normal phase in. Bear in mind the power limitations - if your UPS is rated at a maximum, of, say, 2500W, then you can only have just over 10 amps on it.

Depending on the power requirements of your computers (think about getting TFT monitors, for example), you could perhaps five sockets each of two amps, (about 450W/socket, easily enough for most PCs and an attached monitor).

Put the sockets on RCDs. It's not strictly necessary, but if you're as inept at wiring as you sound, it might just save your life.

So, you run new sockets from your new consumer unit, marking them red or something. You DO NOT want to wire things in the way you describe. Not only is it dangerous, but I think that if you inspect your breaker cabinet you'll find it quite difficult to do. ;-)

Re:Code is the key here.

[anthony_dipierro]

Don't even think about doing this without talking to your city's electrical inspector.

I would think in the US the constitutional right to privacy would preclude Big Brother from getting involved in this, as long as you don't sell or rent the house, anyway. Besides, it's not like the govt. is going to find out. Personally I'd talk to someone who knows what they're talking about, but not necessarily the city's electrical inspector, since it's just a temporary and easily removable hack.

Re:Code is the key here.

[anthony_dipierro]

It is safe: If someone does something stupid, the panel's fuse pops before the UPS does. No smoke. No fire.

I wouldn't rely on a fuse, but rather put a GFCI in at the panel. Now one concern I'd have is whether or not the UPS can handle all that power going through a single socket. You're not even supposed to hook up a single splitter or extension cord to most UPSes. Hooking up an entire circuit likely won't work.

Re:Code is the key here.

[karnal]

if your UPS is rated at a maximum, of, say, 2500W, then you can only have just over 10 amps on it.

Keep in mind that the UPS the submitter referenced is a 120V solution, which will be around 22-24 amps for the 3000 VA......

Re:Code is the key here.

[Anonymous Coward]

The government may not find out but you can be sure as shit that the insurance company will, when they investigate why your house burned down.

Re:Code is the key here.

[BRTB]

1 word: insurance.

If the house burns down (due to electrical something), and they find any evidence that there was wacky out-of-code electrical wiring going on, whether it was the cause or not, then they'll try to deny the claim right off.

Re:Code is the key here.

[GoRK]

You can have your privacy, but when your house burns down and takes your neighbor's homes with it and they find this... you are going to be in a world of hurt with your insurance companies and probably the police. You can do a lot of stuff in your own home that's not legal for various reasons. Regardless of whether or not the idea has merit or is valid or even could be done safely, wiring a UPS into the breaker box is most assuredly against electric code and in the event of an inspection or investigation wouldn't even come close to being a violation that is plausibly deniable.

Of course there are a whole bunch of technical reasons you can't just feed the UPS power through the breaker box easily either, but I'm assuming that most of those will be addressed in other comments egging this guy on.

Re:Code is the key here.

[adolf]

You misunderstand the purpose of a fuse, and a GFCI.

The fuse exists to protect against fire. It heats up and melts, breaking the circuit, before any series-connected wire gets a chance to.

The GFCI exists to protect against electrocution by way of detecting ground faults and shutting down.

Different animals for different problems.

You always have a fuse, even if you don't install one: If things short for whatever reason, something is going to fuse/flash/melt/burn, and it may not be. Everyone agrees that it would be better to use a device made to burn up (or turn off, in the case of a breaker) safely, instead of a random segment of installed wiring heating up uncontrollably.

A GFCI, even if generally a good idea, is only needed in situations where ground faults are likely. Like wherever there's water. Which, hopefully, is not one's server room. A GFCI does not limit current, and does not protect against fire.

And: "Not supposed to"? I think you already discredited yourself, but I'll bite anyway. It'll work fine - it's just a longer length of wire. Some UPSs have restrictions on the type of load (many APC UPSs specify that they're only suitable to power computers), but some others do not. One of the monster Best Ferrups UPSs I have at home is rated to provide 15 amps@120V, unrestricted - it can (and does) start and run vacuum cleaners and power tools without complaint.

Re:Code is the key here.

[anthony_dipierro]

C'mon, how likely is it that the house is going to burn down from something electrical not related to the system you set up? That's a bit too much paranoia there.

Re:Code is the key here.

[anthony_dipierro]

You can have your privacy, but when your house burns down and takes your neighbor's homes with it and they find this... you are going to be in a world of hurt with your insurance companies and probably the police.

I didn't say you should be able to do something unsafe. I'm just saying you shouldn't have to have Big Brother check off on it.

Regardless of whether or not the idea has merit or is valid or even could be done safely, wiring a UPS into the breaker box is most assuredly against electric code and in the event of an inspection or investigation wouldn't even come close to being a violation that is plausibly deniable.

Like I said, if you're going to rent or sell the house, then you're going to need an inspection, and all bets are off. But until then, as long as what you're doing is safe, it's probably within the electric code, and certainly should be.

Re:Code is the key here.

[anthony_dipierro]

The GFCI exists to protect against electrocution by way of detecting ground faults and shutting down.

And a ground fault can't cause a fire?

A GFCI, even if generally a good idea, is only needed in situations where ground faults are likely. Like wherever there's water. Which, hopefully, is not one's server room.

I assume the UPS would be installed at the circuit breaker panel, not in the server room. If you're going to put it in the circuit room, what's the point? Just plug the stuff directly into the UPS using extension cords if necessary. Between the breaker panel and the server room there is plenty of possibility of a ground fault. If a rat bites a wire or a flood comes, that's going to cause a ground fault, right? Also, because you have to run the wires to the UPS and back to the wall, the wires are likely going to be more out in the open increasing the chances of something bad happening. I suppose you could put the UPS in a box on the wall next to the breaker panel and use high quality wire between the two boxes, so maybe it is overkill, but a GFCI circuit breaker is cheap enough, we're talking what about $50?

A GFCI does not limit current, and does not protect against fire.

It does if you use one of those GFCI circuit breakers that you install in your panel box, which does limit current and does protect against fire (any GFCI is going to protect against some types of fires).

And: "Not supposed to"? I think you already discredited yourself, but I'll bite anyway. It'll work fine - it's just a longer length of wire.

Not just a longer length of wire, it's also splitting a single outlet into multiple loads. I can't imagine the UPS can provide well conditioned power to multiple devices through a single circuit. Even if it can, by increasing the distance of the cable you're increasing the potential interference.

Re:Code is the key here.

[yuri benjamin]

In some countries, all new power outlets need a GFCI (called an RCD in New Zealand).
Not just in water-prone places.
A kid can stick a fork into any outlet. An RCD will save lives.

Re:Code is the key here.

[David Horn]

Sorry, I'm British.

It's kind of embarrassing really, I keep needing to apologise for my nationality more and more lately. I meet Germans and feel the need to apologise for MY nation's conduct in the war...

Re:Code is the key here.

[Anonymous Coward]

The UPS is an appliance, not a fixture. It has to be separable from the building wiring by a plug. It doesn't carry the appropriate ratings and classifications for being wired-in.

Some of the larger units are designed to do just that.

Re:Code is the key here.

[tonsofpcs]

If you're going to put it in the circuit room, what's the point? Just plug the stuff directly into the UPS using extension cords if necessary.
Because in many places, using extension cords/power strips* permanently is against code.

It does if you use one of those GFCI circuit breakers that you install in your panel box
Well, that would be a circuit breaker, wouldn't it?
Not just a longer length of wire, it's also splitting a single outlet into multiple loads.
And a power strip isn't?

Even if it can, by increasing the distance of the cable you're increasing the potential interference.
And extension cords won't?

* note the use of "power strips", not "surge suppressors"

Re:Code is the key here.

[anthony_dipierro]

Because in many places, using extension cords/power strips* permanently is against code.

And hooking up a standard UPS to your circuit isn't?

Well, that would be a circuit breaker, wouldn't it?

Yep, not sure where I said it wasn't.

"Not just a longer length of wire, it's also splitting a single outlet into multiple loads."

And a power strip isn't?

I wouldn't recommend hooking up a power strip to a UPS either.

"Even if it can, by increasing the distance of the cable you're increasing the potential interference."

And extension cords won't?

Sure they will, though not nearly as much. Using an extension cord on a UPS isn't the best idea, you should really plug in all your devices directly if you can.

Re:Code is the key here.

[adolf]

And hooking up a standard UPS to your circuit isn't?

What? You'd expect a non-standard UPS to be somehow more suitable?

People do this shit all the time. Properly. Safely. To code. With "standard" UPSs.

There's even documentation describing at least two ways to make it happen here, from people who have a vested interest in not being sued over improper installations.

I wouldn't recommend hooking up a power strip to a UPS either.

Is there anything that you do recommend?

I mean, clearly, it's just impossible to supply a building with power AT ALL. It's just unsafe. Those slippery little electrons might leak out of the outlet and cause a nasty accident, at best, but it's even worse if they stay bottled up inside of the wall, emitting CHAOS and PANDAMONIUM.

Electricity is unsafe. There is simply no safe way to use electricity.

Think of the CHILDREN!

Re:Code is the key here.

[anthony_dipierro]

What? You'd expect a non-standard UPS to be somehow more suitable?

A UPS that is meant to be hooked up to a whole house circuit is more suitable for hooking up to a house circuit than a UPS that is meant to be plugged into the wall. I thought that was kind of obvious.

Re:Code is the key here.

[adolf]

And if the obvious uses were the only safe, reasonable, and useful ones, you could just forget about this whole Intar-web thing, let alone discussions about how to integrate a UPS. We'd still be trying to reliably create fire for heat.

Thanks for playing. You're still a moron.

Re:Code is the key here.

[Lehk228]

the constitutional right to privacy only applies to abortion

if you want to grow a plant in your basement then burn that plant without ever leaving your property you have not only engaged in commercial activity, you have engaged in interstate commercial activity. because of this the Federal government will put you in jail.

Re:Code is the key here.

[anthony_dipierro]

the constitutional right to privacy only applies to abortion

Considering that it also applies to sodomy, you're clearly wrong.

if you want to grow a plant in your basement then burn that plant without ever leaving your property you have not only engaged in commercial activity, you have engaged in interstate commercial activity.

That's probably not true, but no case has yet been brought over such a thing. Wickard v. Filburn is close, but if there's no legal market for the plant you're talking about the argument that growing it for personal consumption affects interstate commerce by replacing a product you would have consumed in interstate commerce doesn't apply.

because of this the Federal government will put you in jail.

Assuming you're talking about pot, no they won't. Cultivation without intent to distribute is not illegal under federal law.

Re:Code is the key here.

[Lehk228]

I guess there are two ways the right to privacy applies i was not aware that was the basis for the ruling against sodomy laws.

Possessing almost any significant quantity of pot (btw i do not use pot) counts as intent to distribute. without requiring any evidence that distribution actually occured

Re:Code is the key here.

[anthony_dipierro]

I guess there are two ways the right to privacy applies i was not aware that was the basis for the ruling against sodomy laws.

No, there are many more than two. Read about it some time, you don't seem to be aware what the right to privacy is.

Possessing almost any significant quantity of pot (btw i do not use pot) counts as intent to distribute.

Not under federal law it doesn't. It might create a rebuttable presumption of intent to distribute, but that's not the same thing.

What would Ricky Ricardo say?

[NanoGator]

"Basically I want to find the breaker for the room, and after the breaker, run the power through the UPS and back out to the room. Is the UPS that I have sufficient to run a whole small office?"

Considering that you're married, are you really sure that you want to embark on a project that has the potential to make you a permenant laughing stock at the beauty salon?

Keep in mind

[Guspaz]

Line-interactive UPS units like the 3000NET DO NOT filter power. They have AVR, which only filters huge changes in voltage. It will not kick in for even extremely dirty power. It is simply meant to boost up the voltage if your power drops down to, say, 90 volts, or goes up to 150 volts.

So keep in mind that really all the UPS is going to give you that a good power supply can't is battery backup and surge protection.

Re:Keep in mind

[TangoCharlie]

I knew I was going wrong somewhere.... my line voltage is well over 240 volts!

Re:Keep in mind

[Guspaz]

I was referring to North American voltage, IE that in Canada.

AVR works based on percentages. If your voltage drops more than x percent below optimal, it boosts by x percent. It does not boost back up to optimal, it boosts by x percent, no matter how low it goes.

On my APC unit, AVR is totally useless; the UPS unit is configured to switch to battery power before AVR could kick in. TO be honest I sort of feel like APC is misrepresenting the capabilities of AVR, and what AVR does. When you actually email APC to ask them exactly how AVR works, the response they give you shows how AVR really isn't nearly as useful or effective as they make it out to be.

Why do I sort of feel cheated? I purchased the unit because I have dirty power and I wanted to have it cleaned. Turns out even though APC seems to claim as much in their product documentation, line-interactive UPS do nothing of the sort. You need super expensive online models to do that, or some overpriced MonsterPower component.

What you really want

[ReverendRyan]

If you're trying to keep working during a blackout (as opposed to keeping your RAID consistent), look into these: a Kohler Generator. Sure, you still need a small UPS for your server/desktop, but it only has to last ~45 seconds until the generator kicks in. Have an electrician (or authorized Kohler rep) install it. I wish I had one sometimes.

YMMV

Re:What you really want

[csnydermvpsoft]

Another good brand is Generac. Home Depot and Habor Freight both sell them. We got a 15 kilowatt one to power most of our office (which is in a small house). All the computers are covered, plus a lot of lights and a fridge and freezer. It runs on natural gas (or LP if desired), so we don't have to worry about fuel.

One thing to keep in mind - many UPS's don't like generator power. I'm in the process of replacing our old cheap-as-possible UPS's with APC SmartUPS's (used with new batteries, of course) because they can handle running off of the generator.

Just go PV

[RingDev]

If you really want to isolate the system look into installing a photovalitile roof system. Not only can you keep your whole house up and running during power outages, you can reduce your monthly power bill. ;) And those system, while still a challange to get OKed by the building inspector, can get federal and state funding, tax incentives, and even cash from your power company.

See http://www.dsireusa.org/ for more info on your local photo volatile power system incentives

-Rick

Re:Just go PV

[alienw]

It's only worth it in California, really. Few other states have the incentives or the climate to make this worthwhile.

Re:Just go PV

[RingDev]

have you looked at the dsire site? Here in Wisconsin I can get half of the expence paid for by the state, tax exemptions on any increase in property value becuase of it, net metering on the juice (If I produce more juice then I use, I get paid for it) and my power company will pay me $1000 up front and I can apply for up to $500 maintenance every few years if needed. I can even take out a $30k interest free loan to pay for the system.

Also, Cali isn't the best place for solar power. AZ has it beat, but you'd be supprized how much of the rest of the country averages Zone 3 or better. Even here in Wisconsin with a small roof you can push out just shy of a megawatt ever year. Larger roof lines can do even better. Cali is just a hot bed for this activity because of it's social atmosphere (damn hippies) and the power market instability (thanks to ass hats like Enron pumping power in and out).

-Rick

Re:Just go PV

[jpostel]

NJ has some of the highest incentives and rebates in the country. http://www.solaraenergy.com/ "Solara has completed the installation of an 88kW PV installation for a school in New Jersey. The project was made possible by the enticing rebate offered by the New Jersey BPU which will cover 60% of the project's cost."

Re:Just go PV

[numbski]

Okay, I'll admit ahead of time this is me speaking out the lesser end of my body. That said...

What very very little I know of solar panels and Windmills (wind turbines to be exact) is that solar panels are (last I knew?) very inefficient in that it takes more power to make the panels than what they can create over the span of their lifetime, thus the reason I've never bothered looking at them.

Wind turbines rock. They're fun to look at, dangerous to make (huge freaking magnets that you're trying to *gently* set into a wheel with opposing poles dangerously nearby. hope you didn't want that hand...), and energy-efficient. The problem is that here I don't have the land-space to do it, couldn't get a permit to put it on the roof, and many braindead people around here think that they are eye-sores. Pfft.

So I had a moment of curousity. What about pinwheels instead of one huge turbine?

I'm not joking (I don't think?), you could probably get a set of small magnets, make a little alternator and build it into several pinwheels, and use some outdoor-safe wiring to run the power they generate back to some batteries near/in the house. The question becomes one of whether a garden of small pinwheels can even come close to the power generation of that one big wind turbine. :\

Oh, btw...for the guys considering the solar panels on the roof, it then goes without question that you're not going to want to block the panels with a shade tree, meaning your roof is taking direct sunlight. There was an article that got posted to digg.com a few weeks back about little things you can do to keep you house cool without AC, and one is a special reflective paint that is usually intended for mobile homes and RV's. You paint this on the roof, and it is supposed to reflect the majority of radiation. Look here, and start reading where it says "Installing a Radiant Barrier". The first paragraphs talks about a foil barrier beneath the roof (awesome idea, btw) and the second about the paint, which is really a type of asphalt.

Good stuff. This way you get your solar energy in DC, not in heat. ;)

Re:Just go PV

[RingDev]

"is that solar panels are (last I knew?) very inefficient in that it takes more power to make the panels than what they can create over the span of their lifetime,"

No longer true. current theoretical limits put the power generation at 30% of the power received by the sun. And life spans of 20+ years. New thin film technology is allowing PV cells to be made cheaper and easier, and in much better applications. Gone are the huge 6 foot panels. Now you can get a PV sheet that can be rolled up and put in a backpack for power on low impact camping trips. Companies like UniSolar produce integrate PV roofing. Which are roll out solar power shingles, looks just like a normal roof, only a little shinier. If you are replacing your roof anyways, gov funding will pick up most of the extra costs and the power savings will pay off the remainder well before the end of it's life cycle.

"huge freaking magnets that you're trying to *gently* set into a wheel with opposing poles dangerously nearby. hope you didn't want that hand..."

They're not that big. There was a story posted here a few months about about building your own 30' tower. The problem is, in order to harness the really strong winds, you need to get 30m+ off the ground. We have a new wind farm being built in Wisconsin, each turnbine is 130' tall, with 100' blades if I recall correctly. so at it's highest point, the blade tip is 230' above the ground. Great for wind generation, but they're freaking huge. Nebraska is the place to do it though, huge flat plans with tons of wind. If Nebraska had the infrastructure, enough wind farms could be built to power the entire western half of the US.

-Rick

Re:Just go PV

[geoffspear]

Repeat after me: a watt is a unit of power, not of energy.

Do you mean you can generate a megawatt hour every year, or you can constantly have an output of 1 million watts for a year?

Re:Just go PV

[Intron]

There was just an article on this in one of the pop science magazines. PV cells pay back about 7 times their energy cost to build. Wind turbines only pay back about 5 times. Corn-based ethanol is currently the worst energy source out there, costing 1.3 liters of oil per liter produced, about the same ratio as hydrogen produced using electrolysis.

Best energy sources (in terms of payback and renewability) are wood heat (1:22) and hydroelectric power (1:28). They didn't cover nuclear, since it isn't an option in the current political climate.

Re:Just go PV

[RingDev]

My bust. You are correct, a small roof in wisconsin can produce 800+ kWh of energy.

-Rick

Re:Just go PV

[Pii]

They didn't cover nuclear, since it isn't an option in the current political climate.

And that's a shame, because if the US hopes to achieve any kind of realistic energy independence, nuclear power holds the key. It's the cleanest, most efficient energy source we have available. The advances in reactor design have eliminated any perceived "disaster possibilities," and dramatically reduced the amount of waste product.

Re:Just go PV

[VolciMaster]

And that's a shame, because if the US hopes to achieve any kind of realistic energy independence, nuclear power holds the key.

Interestingly, that's the exact point being made by many global warming scientists. The only drawback to nuclear power generation is disposal of waste materials. However, a very small quantity of fuel lasts a really long time, so disposal isn't a constatnt issue, only a periodic one.

Re:Just go PV

[Intron]

Speak of the devil

Re:Just go PV

[JustAnotherBob]

100' blades huh. I wonder how many migratory birds they can slice and dice per revolution. Sounds like we got the makings of a fantastic infomercial to me, I can just see it now. "Billy Mays here..."

Re:Just go PV

[wik]

If you trust the national wind coordinating committe, not that many birds get killed:

http://www.nationalwind.org/publications/avian/avi an_collisions.pdf

not a good idea

[bmwm3nut]

not everything can be run off of a ups. most ups waveforms outputs are sawtooth rather than sine wave. most things are down converted to DC so it doesn't matter what the waveform is as long as it's 60hz and goes to the right voltage peaks. but some things care about the waveforms. i think flourscent lights are one, and i remember my ups came with a warning to not run a laser printer off of the ups.

if you want to mess with internal wiring then i suggest two circuits for your home office, one connected to the ups and the other just straight from the grid.

Re:not a good idea

[alienw]

You can't run laser printers off of normal UPSs because laser printers consume huge amounts of power (thousands of watts) when they are printing. It would probably overload the UPS and trip its breaker or at least drain the battery quite a bit.

Re:not a good idea

[Anonymous Coward]

From apc "Due to the large amount of power consumed by these devices, APC does not recommend protecting
laser printers with a UPS. In most cases, surge protection is adequate for laser printers." Notice you can put a laser printer on the UPS just not battery back up.

To comment on some of the above statements as well. Any device that connects to my comptuer goes through some sort of surge protection. I have a APC UPS i forget the model number its older. The tower and monitor are on battery back up everything eles is on surge (speakers, modem, ink jet printer etc.) My lan (RJ 45 cable) even has surge protection. Ive seen computers fry from some kid hitting a telephone pole and a surge goes in through the modem. All it takes is one instance and you can fry a computer. Better to be safe then sorry. My ups while in college saved me on more then one occation.

Re:not a good idea

[HTL2001]

"most ups waveforms outputs are sawtooth rather than sine wave"

in the specs, it says this one (the one he is using) is sine wave

Re:not a good idea

[Lehk228]

laser printers just consume too much juice for any UPC lacking a nuclear reactor. My clock/radio goes nuts when i try to power it off a UPS, not only lost the time the display flickered random lights but somehow it wasn't damaged.

Obvious things first

[secolactico]

As with any other electrical question on slashdot, here's the thing you should keep in mind:

Electricity can kill you and/or burn your house down if you are not 100% sure of what you are doing.

Seek the help of a professional who should then measure the loads in the area you want to protect and recommend an appropiate product.

Don't even think of using an off-the-shelf UPS in any configuration other than the one the manufacturer recommends (regardless of capacity).

A/C and lights can put a heavy strain on UPS. It's customary to leave them out of it.

As another poster mentioned, you might have to get permission from your local safety office/fire department.

Re:Obvious things first

[JavaRob]

By the way, you don't need to deal with a regular electrician that might not understand the details of a UPS -- there are companies out there that specialize in UPSs and backup power, etc.. My uncle Pete has a business that does exactly that, so I know they exist. [sorry for the shameless plug...]

Even if you're keen on doing it yourself and you have the electrical knowhow, you can get some good advice -- since you're looking to buy batteries for the thing, you've got their ear. Personally, I suspect they'll tell you what most other posters here have mentioned (that putting the whole room on the UPS isn't the greatest idea), but presumably they'll have suggestions for a good compromise.

here

[zogger]

here, homepower magazine

http://www.homepower.com/index.cfm

you will like this mag if you have never seen it

This is the sort of project that alternate energy folks do all the time, ie, using battery backups then to the house circuits. It is common. Whether the original juice is from solar PV or wind gennys or microhydro, fuel generators-or the grid,or a combination of the above, which most enthusiasts have, the wiring is very similar. They have a nice searchable archive of all their past articles, and you can review inverters, grid ties, separating circuits, charge controllers, etc.

With that said, with just the one UPS, I think just plug it in and plug your computers to it like normal. HOWEVER, what you want to do, isolate one room and have that circuit backed up with banked battery power and have the current being a lot cleaner than the grid juice, IS a doable project, and really isn't that hard. Frankly, I am amazed more geeks aren't into doing it. You don't need the expensive solar part to have a day or two (whatever...) of decent backup power stored in a battery bank. Later on if you get the bug you can add the solar or wind power. Neat stuff in that way, highly customizable and modular. Lot of nice current tax breaks as well for homeowners.....

Re:here

[Anonymous Coward]

With that said, with just the one UPS, I think just plug it in and plug your computers to it like normal. HOWEVER, what you want to do, isolate one room and have that circuit backed up with banked battery power and have the current being a lot cleaner than the grid juice, IS a doable project, and really isn't that hard. Frankly, I am amazed more geeks aren't into doing it. You don't need the expensive solar part to have a day or two (whatever...) of decent backup power stored in a battery bank.

Huh??? I've rigged my entire house this way, and it certaily wasn't cheap or easy. 16 deep cycle 360Amp-hour batteries, dual Trace 5500Watt inverters, generator, and install was around $20,000 back in 1999 when I installed it. To do it safe (and to NEC code), you'll need to break that room into it's own circuit panel and connect the inverter between the main circuit panel and the room's panel. And don't forget the conduit. Then there's a transfer switch if you want a generator, high amperage breakers for the battery bank, transer switches to take the inverter out of the loop if necessary, venting if you choose lead acid batteries, etc.. It's more involved that you realize, even for a single room.

Having said that, it was definately a fun and interesting project, and I haven't lost internal power for 1 second in the last 6 years. All 120V circuits are connected to the inverters. Together, the inverters can generate 11KW and the batteries have a capacity of around 32KW-hours, which should power the entire house for a day or two given my expected loads. And after that, I have my generator. The system is fully automated; it can even turn the generator on and off by itself.

don't waste the power

[TheSHAD0W]

If I were you I'd only run the computer and monitor, perhaps a small desk lamp, and maybe the wall wart for your phone, through the UPS. All the rest will just run it down more quickly in exchange for protection from something they can weather easily enough anyway. This is especially important if you leave the computer on while you're away; the UPS could keep the machine powered through a blackout of moderate duration if it only ran the PC, while it'd cut off early if it had to power everything else.

Get real.

[sakusha]

I can understand you wanting backup power for your server, but is it really that important that your gaming machine have uninterruptable power? How many times do you get killed in a game and have to go back you your last saved game anyway? Come on..

I have a rig in my office that is sort of like you proposed. I have a Belkin 1100 UPS, I have both my desktop & monitor and my headless server drawing power from it, it's rated to cover both systems for about 15 minutes. Around here there are occasional 2 or 3 second outages, but I live close enough to the power plant that the last outage that lasted more than 10 minutes was a major tornado that cut power to the whole city for 3 days. So consider what kind of power backup requirements you really need to cover.
I figure that I can wire my server to the UPS's USB data port, and the server will do a clean shutdown after about 10 minutes, when the battery level signal indicates imminent loss of battery power. If the server gets the signal, it does a clean shutdown, but my desktop doesn't, it has no way to know it's about to lose power. But I figure that is adequate coverage for outages up to about 10 minutes, the server is more important and gets controlled shutdown, the desktop gets some backup but will go down hard after that runs out.
Now if you need more serious coverage than that, for multiple CPUs, you need a professional install of a serious power system. Or maybe you should just switch to laptops, which have their own battery backup power.

Re:Get real.

[vericgar]

I may be wrong here, but I though the software that came with my Belkin UPS had an option of sending a network broadcast that (if other computers on the network are running the software) would know to shutdown as well. Just something you may want to look into for your desktop.

Re:Get real.

[kv9]

If the server gets the signal, it does a clean shutdown, but my desktop doesn't, it has no way to know it's about to lose power.

if your model is supported then this might help you.

Re:Get real.

[way2trivial]

why not just shut it off at minute nine when it starts beeping?

Re:Get real.

[sakusha]

Well yeah, that is the obvious move, if I'm at the desktop I'd shut down if the outage was more than 1 minute, to maximize power reserves to the server. I thought this was obvious enough that I didn't bother to say it. But I also leave my desktop CPU running unattended for hours on end doing file compression or downloads, in those cases I'd rather leave it up and running to avoid the loss of hours of work.

Re:Get real.

[sakusha]

Darn it, looks like my UPS is unsupported officially, but it probably wouldn't be hard to hack in support. Thanks for the tip.

Don't Do It!

[aaarrrgggh]

These little UPS things, especially in a home environment, are really the wrong solution.

More likely than not they pose added risk of fire. They are a cheap consumer device with a short life. Don't make them permanent. Make them easy to unplug.

You'll loose flexibility...

[WoTG]

Besides the electrical code violations, you'll loose flexibility in what you can power in the room. Laser printers and other very high current appliances (maybe microwaves?) will not be good for your UPS. I've seen laser printers cause UPS's reset themselves. It's not fun having workstations loose power every time someone tries to print. =)

Re:You'll loose flexibility...

[Anonymous Coward]

'lose'

Been there, done that

[SomethingOrOther]

In my post-doc days a housemate got hold of a UPS powered by a massive array of car batteries in the garage. He wired it into the house such that in a power outage, only his room (admitedly containing the house servers as well as his personal computers, lights, TV etc) would have power.

We did have a half-hour power outage during a storm and it worked fine when the rest of us were looking for candles. The main drawback was it did SAVAGE things to our electricity bill, more than doubleing it. Keeping an array of lead-acid batteries charged up 'just in case' is not cheap.

Do what we did and save money buying a bog standard normal UPS, either that or get someone else to pay your electric bill.

Safety Nazi Mode Also leave a note on your house fusebox/master switch warning whoever turns the power off that one room in the house will still be live. (Very important in the UK where mains is 13A 230v that can be enough to kill, unlike US 110v mains)

Re:Been there, done that

[cloudmaster]

You can pretty easily be killed by 110V as well, it's not really significantly safer than 220...

Re:Been there, done that

[I confirm I'm not a]

You can pretty easily be killed by 110V as well, it's not really significantly safer than 220...

As my old physics teacher used to say: "it's not the Volts that jolts, but the Mills that kills."

Don't do it

[Compuser]

My lab recently did this. We got a huge (> 10 kVA) UPS and
set some outlets to be on this UPS. Not all outlets, but even that
is very tricky. Basically grounding arrangements are very
difficult to get up to even national electrical code,
and you also got to worry about local regulations. Basically,
if you do want to do this, the UPS itself (even the beefy
powerware models purchased at full price) will likely be the
least of your expense. The rest will go to licensed electricians
for installation.

UPS? uninterruptable?? sure

[SillyNickName4me]

For whatever reason, over the last 10 years, I have seen more power failures being caused by a UPS then being handled properly by one.

The idea seems to be good and usefull, but so far reality tells me that those devices do not have the kind of reliability that is needed.

One of my customers has their entire computer room wired up to a HUGE UPS, and has a few smaller ones in place for very important servers. The big UPS is supposed to keep them running for as long as power lasts, the small ones are to allow those servers to properly shutdown when power runs out on the main UPS.

In the last month, they had 2 major failures of the main UPS, resulting in a substantial amount of downtime. They cannot remember the last failure of mains power (I do, and it is a few years ago now)

My own company used to have a very nice IBM AS/400 with UPS (one made specifically for this machine), which failed during the one power failure we have had in the last couple of years here, not to mention it deciding to just switch off a few times over the years.

Another one of my customers runs a bunch of servers with redundant power supplies where each power supply has its own UPS. That setup sees to work a lot better already.

To me the story seems pretty simple:

1. Make sure your software infrastructure can deal well with the consequences of a power failure. Determine what would be an acceptable recovery time in case things go wrong and make sure you have the procedures in place to do such a recovery, and that it is well tested (and retested every so often). There is no amount of hardware redundancy that will be as effective for dealing with the consequences of power failures as this bit of software related efford.
2. Make sure you have redundant power supplies with a seperate UPS for each.
3. Consider a UPS as a means to be able to save your work and properly shutdown your machines. It is not something for actually keeping your machines running during a power failure, if that is really what you need, consider a generator instead.

Re:UPS? uninterruptable?? sure

[smellystudent]

I've had a load of small APC UPI (plural of UPS :-)) which kill the outlet power when the internal logic decides that the battery's dead. The engineer in me says "sound a loud alarm, page the swashbuckling sysadmin, but don't cut the doddam power!!"

This may just be me being picky.

Re:UPS? uninterruptable?? sure

[Chanc_Gorkon]

And that is crap.....

We have ALWAYS had a while room UPS. Call Liebert or whoever your vendor or electrician is and have them fix it. We have in our center a UPS to cover the interim time it takes for the generator to kick on. Our Generator is across the street. While we had issues after we first moved in, they have been resolved and we have lost power since and our room stayed up and so did our website. God pless the power fairies....

Re:UPS? uninterruptable?? sure

[SillyNickName4me]

We have ALWAYS had a while room UPS. Call Liebert or whoever your vendor or electrician is and have them fix it. We have in our center a UPS to cover the interim time it takes for the generator to kick on. Our Generator is across the street. While we had issues after we first moved in, they have been resolved and we have lost power since and our room stayed up and so did our website. God pless the power fairies....

Within some time, where I live I will have the option of contracting 2 seperate electricity providers each with their own wiring going into the building..

But as I mentioned before, a huge UPS for the entire computer room itself is not a bad idea, but after having seen many a UPS fail in the last decade, including properly installed ones at places that can afford to spend a fortune on them, I consider them to not be extremely reliable, at least by far not as reliable as their producers would like you to believe. And as I also mentioned, I have simply seen more power failers being caused by them then being handled properly. That is in part due to mains power being very reliable here of course. This is not in one environment, it is in hundreds of environments, with devices from a wide range of producers. I will use that to base my judgement on over your annecdotal evidence if you don't mind.

Re:UPS? uninterruptable?? sure

[Chanc_Gorkon]

A UPS is only supposed to give you either enough time to turn everything off safely, or to give you enough power to keep everything up while the generator starts. If you value every single minute of up time, you have at least a UPS and a generator for cutting over. They UPS's are not supposed to last a long time. On the otherhand if you don't have a service contract and you do not do maintenance like checking the batteries and what not, then you have noone but yourself to blame. UPS's are not designed to be carefree. They need care and handling.

Geek Express

[jkirby]

This is what I am using for my UPS here at home:

1 x Lister-Petter 7.1 KWh diesel generator ~$6,000
1 x Trace/Xantrex T240 autotransformer ~$300
1 x Trace/Xantrex SW 4024 inverter ~$1,500 on ebay NIB
12 x Fulmen 2.2 volt batteries at 1900 amp/hours each ~$4,000 for the lot (delivered)
2 x Starband connections for backup (www.starband.com) ~$1,000.00
1 x /. post - priceless

This gives me about 50 KWh backup power; I just wish I could still find some of those 7000 amp/hour submarine batteries.

A small and common UPS

[Anonymous Coward]

Why not use laptops for everything?

They have an inbuilt UPS device: a battery!
And the monitor is on a UPS too!

Dunno about running it as a server 24/7.

Use the sizing tool...

[Kevin Burtch]

APC has a UPS sizing tool on their website... just enter all of the items in it that you plan to connect to the UPS, and it will not only tell you whether or not you are within its abilities, it'll tell you how much room you have to grow, and more importantly - how much run-time you'll have.

15A

[droyad]

This UPS requires a 15A circuit (for 240V, 30A for 120V). You will need to get a special plug. As for is it enough? Yes. You can run 3 _real_ servers off that.

Downside is the battery is going to be expensive. You will be better off getting two 740VA back-ups units.

Re:15A

[karnal]

Actually, his UPS uses the RBC-11, which you can get full packs for (4x12v, 18ah batteries) from Ebay for around 100$ shipped.

And yes, they are brand new batteries.

Additionally, the batteries used in this UPS are bigger than typical rack-mount setups (in terms of energy and size.)

Car Batteries

[ers81239]

I know a guy who gets old UPS' from the junkyard and then hooks them up to regular car batteries. They work great and last for a lot longer than the batteries that come with them. Not sure what you would need to do to scale that up to your application, but you should be able to save a ton of cash.

Re:Car Batteries

[ksp]

Check out the Ghetto UPS which I believe has been discussed here before.
Warning: building something like will probably kill you and others through electrocution, fire, or something completely unexpected.

Re:Car Batteries

[daedalus-prime]

...regular car batteries

But make sure you get the completely sealed type of car battery. Most car batteries are designed to vent corrosive and toxic gasses during charging and discharge!!!

House Surge Protector and so forth . . .

[Dausha]

Somebody above said you had to contact your city's electrical inspector. That's a little heavy handed. Hire a certified electrician. Inspectors only show up on new construction, if I'm not mistaken. Now, my two cents . . .

Go ahead and mount a whole house surge protector. They cost a couple of hundred dollars, take a couple hundred more to mount. But, then you'll have (I think) somewhere on the order of 40,000 joules of protection. Some smart house sites have more information--let Google do the walking.

Second, while you're adding the whole house protector, add a box on the main that will allow you to connect a generator for those power outages. My step-father did that a few years back after an ice storm took out power for a few days. (Before he just ran the cords into the house). He was able to generate enough power to keep the central heat going and other "essentials."

Of course, if you only lose power for a few minutes every couple of years, this may be a little much.

use a generator transfer switch near breaker panel

[Anonymous Coward]

I am currently doing something similar to what you have described:

I have an APC 1400RMXL3U UPS with deep cycle marine batteries sending its output to a low-end 5 switch generator transfer switch, and the transfer switch sends the electricity to key breakers in the house (namely a few outlets in the basement and my office). I had an electrician wire up the transfer switch while finishing the basement so when we move it won't be a total loss. Normal APC UPSs aren't designed to run for hours at a time -- be sure to get a XL model or (better still) a real inverter such as those from Xantrex, Outback systems, etc. otherwise your UPS will fail when the power goes... Pick up a Home Power magazine for ideas. In case we have a real power outage I also have a 7500 watt gasoline generator that can also power the refrigerator, forced air heater, and other loads (though its output is a modified sine wave so I have some Sola ferroresonant line conditioners which happily take this as input and then *regulate* and condition the voltage so the output is always a perfect sine wave with 120VAC RMS)

The good news is that the UPS now lives in the garage where the heat it generates isn't noticed. And the battery weight doesn't affect anything in my office either.

As others have alluded to you still have to worry about grounding and surges (APC UPS's have wimpy surge protection). If you aren't familiar with ground loops I suggest you learn. I have everything in my office powered from one outlet to avoid this (obviously 15Amp load) and the only thing that interacts with the "outside" power is the ethernet cable going to the laser printer which is powered by utility power instead of the UPS - hence a ground loop issue as well as a possible source of surges entering the system. I'm going to solve this by using a bunch of Linksys WRT54GS routers running Sveasoft or OpenWRT firmware in WDS mode (WPA2 for security) so I can eliminate that single ethernet cable going to the laser printer. I currently have a decent surge protector on the laser printer (Tripplite ISOtel Ultra which has the best specs I could find for a MOV-based protector and at a reasonable price; I use ZeroSurge protectors for everywhere including in my office as ZeroSurge protectors don't use MOVs. I have LOTS of lightning where I live)

Another side note: the light switches in my office are now also powered by the UPS so you have to watch the wattage or the bulbs you use.

I've had this setup for almost a year and it has worked well, especially through various lightning storms.

ive got one of these...HPS6000HE

[Zurk]

Ive got an isolated 30A switch to my computer room so i wired in one of these :
http://www.wincogen.com/cgi-bin/products.cgi?mode= DETAIL&partno=16079-029
make sure you get the automatic transfer switch when you wire the UPS in. note that its not CHEAP or EASY to so. i'm a licensed electrical contractor so i could do it on my own but youre not.

That's a REALLY bad idea...

[HaloZero]

...for a couple of reasons. Firstly, you don't want to run the entire room off of the UPS; just your critical computer equipment. My UPS runs my workstation, the router, one display monitor, and typically a linux file/web/services server. It also runs my desk lamp. The UPS I use in particular is nice (and I believe mine is related to yours, in brand) because it has this warning alarm when it's power becomes the primary source of energy. The reason for this is that my particular outlet (I live in an apartment with three other people) is wired to a pair of lightswitches on anterior corners of my desk. We've also noticed that when you turn something on in one part of the apartment, the power will occasionally spike, and without the UPS, reset someone's workstation. But I digress, don't plug the whole room into your UPS. Just what you need on to perform an adequate shutdown of your equipment, in the event of a power failure. Secondly, if you put the UPS on the source side of your breaker, and your house gets struck by lightning, your UPS is going to BLOW UP. And I don't want to be anywhere near it if and when that happens. Circuit breakers are there for a reason. Sure, they aren't the end of the line in protection, you need a surge protector, too. Now, my UPS does have a surge protector in it, but still, I'm sure you see my point by now.

different sizes here

[zogger]

last place we lived had a setup like yours, that is why I am familiar with it. 2.6 kw of solar PV, two separate battery banks, one with 24 trojans, one with 12 rolls/surrettes, stacked inverters to provide both 110vac and 220 for the well, integrated 12 kw diesel genny, and yada yada big wires yada. We even made our own distilled water for the batts with a solar water distiller.

The article submitter just wants to do one circuit, and I don't think he cares about it being solar powered or whatever. The cost would be a lot less than doing any whole house action, but yes, more involved and more costly than just plugging in what he has now and running direct.

With the prices of homes now, and energy credits (add *one PV panel* and it can be a significant cost savings because of the new energy credits), and the ability to have the entire cost rolled into the monthly note, the price per month increase for such a rig wouldn't be that bad most likely, just for the one room. With some research and planning, he could do 90% of the work himself (saving a lot of 20$/hr and up electrician costs), and leave the last to a licensed contractor to check out and verify code worthiness and do the final connections for the inspector to check out. I don't think as serious home improvement projects go it's all that hard for one circuit.

120V NEMA Outlets

[maxrate]

Any Device that has standard 120V AC NEMA plugs and outlets is not meant to be 'tied' into your household electrical system. Having the UPS in the room and plugging only what you NEED into it is better than plugging the whole room into it.

The more load you put on the unit, the less life you will get out of the batteries.

You cannot vacuum clean off a UPS or a modified sine wave inverter.

I wouldn't have any printers plugged into it, or devices with motors or heating elements.

Why did your work throw the unit out? If it's just batteries it needed, I'm surprised they couldn't put it to use somewhere.. Congratulations on the score of some nice hardware!

I am not sure, and I haven't checked the APC page, but does the 3000 Unit require a 230Volt AC input?

My Whole-Home UPS Solution

[InitZero]

> Is the UPS that I have sufficient to run a whole small office?

        Yes.
        I, too, had a surplus UPS about the size of yours. When I
was in my apartment, it sat in the same room as my computers.
The UPS was loud, ugly and produced lots of heat. (Much like
a girl I used to date... but that's an another story for
another day.) It protected my computer equipment but not my
TiVo or home stereo equipment because they were in another
room. So, I had to have a seperate UPS for them.
        When I bought a house, I didn't want UPSes spread all over
the place nor did I want the heat or sound inside the house.
        So, I put the UPS in the garage and then wired UPS outlets
where I needed them. I have a quad-outlet in the office for all
our computer equipment. I have a quad-outlet in the living room
for the TiVo, stereo and TV. My cordless phone and answering
machine also plug into a UPS outlet.
        For nearly five years, this setup has worked great. Every
two or three years, I have to replace the two batteries ($90).
Other than that, it has been great.
        Plus, I have disaster-recovery outlets spread throughout
my house. When last year's hurricanes knocked out power to
my house, I was able to plug the UPS into our small generator.
I didn't run the computers or television (but did keep the
TiVo online so I wouldn't miss my shows) but I was able to
keep some lights on without having extension cords pulled all
over the house.

> I want to find the breaker for the room, and after the
> breaker, run the power through the UPS and back out

        If I were you, I'd run a new circuit. You never really
know what outlets and appliances are where. When I moved
in, the toaster's outlet in the kitchen was on the same
circuit as the outlet on the front porch where I plugged
in my hedge clippers.
        I'm sure there is more on your office circuit than
you know about. It is best to start clean. Plus, electrical
work is really easy if you have attic or basement access.

        Matt

Separate UPS's per power supply, yes!

[Myself]

I've been saying this for years. Unfortunately my only multiple-power supply box (second-hand, cheap) has a single inlet plug, so it would take some work to run each power supply from its own UPS.

In the telecomm infrastructure, everything runs from a DC battery bank, which is maintained by rectifiers. (Or you could say it runs from rectifiers, backed up by batteries. Semantics.) All the equipment has 2 power supplies, and is always fed from two separate DC inputs, known as A and B. In very small (remote equipment hut) installations, sometimes A and B are both fed from the same battery bank, but in most buildings, there are two strings of batteries. You could concievably blow a main fuse on one side, and the whole office would run from the other. (Everything's fused high enough that it can draw all its power from one side or the other, but in normal use, they split the load evenly.)

The DC infrastructure makes telco central offices ideally suited to solar-electric installations, since the inverter is a large part of the cost of a residential photovoltaic installation. (I don't know why we don't see this more often.)

Back to servers. I've got very little experience with redundant power supplies in the PC world. Is the APM/ACPI driver aware that one power supply has failed? Suppose you had one power supply plugged into the "house power" feed, and the other into a small "personal" UPS. Could software notice the failure and begin an orderly shutdown, or would the small UPS have to tell the server, via USB or RS232, about the fact that it's now running on battery?

Re:Separate UPS's per power supply, yes!

[SillyNickName4me]

I am not sure about power supplies using ACPI for this, but I am rather sure that on systems I dealt with, it is quite possible to detect failure of one of the power supplies. I just never looked at what interface it uses.

The problem I see with what you suggest is that you will have to have the UPS connected to mains power anyway so it stays charged. In that case it is pretty easy to just let the UPS tell the system about the power failure, and it still does not address the main reason why I suggest a setup with redundant power supplies and UPSes.

ymmv but where I live, both power supplies and UPSes are way more likely to fail then mains power and a UPS seems more likely to fail then a power supply. This means that imho there is very little point in having 2 power supplies with one UPS, it would in theory be usefull to have a second UPS and only one power supply however if you could connect both UPSes in parallel somehow.

Btw, I picked up using backup power in such a way from the telcos here indeed.

Re:Separate UPS's per power supply, yes!

[Myself]

Around here, commercial power isn't very reliable. Every summer storm produces at least a few momentary dropouts, and we're typically out for a few hours each year. Sometimes several days, but that hasn't happened recently.

My point was that the main building supply would be the giant UPS, or generator, either of which can fail in various ways. Two small UPS units, one per power supply, would just add expense. All you need is one, to sustain the server until the generator kicks in, or the main UPS is back online, or the server shuts itself down.

Re:Separate UPS's per power supply, yes!

[SillyNickName4me]

My point was that the main building supply would be the giant UPS, or generator, either of which can fail in various ways. Two small UPS units, one per power supply, would just add expense. All you need is one, to sustain the server until the generator kicks in, or the main UPS is back online, or the server shuts itself down.

Ok, I understand that, and as I mentioned already, one of my customers is using such a setup (huge UPS for their computer room, and small UPSes for specific servers). As I also mentioned, they experienced quite some trouble with this setup due to the main UPS failing. But generally spoken, this idea makes sense.

Having one power supply connected to a UPS and the other not however makes a bit less sense to me. Sure, a UPS failure wont bring the machine down, but problems seldom come alone. Murphy will tell you that main power and the one power supply that has the UPS are bound to fail together. Just realize that the second UPS has quite a dramatic impact on failure chance. Lets just say that failure chance on a UPS would be 3% (just picked a random number for this, its unlikely to really be 3%), having 2 of them fail simultaneously has a 0.03 * 0.03 chance, which is really a dramatic improvement.

When it comes to being able to properly handle a power failure and guarantee that servers shutdown cleanly and everything gets saved, I would give up on the "huge" backup power for the building before giving up on a seperate UPS for each PSU.

Re:Separate UPS's per power supply, yes!

[myov]

Most servers with built-in redundant power supplies have additional monitoring software.

If you mean two power supplies in the space of a normal ATX p/s, then the only monitoring you would have is if there was an additional serial/usb connection to the board.

Servers at home?

[coyote-san]

Why run your web server at home?

I'm serious. Having a local print and file server is fine. I ran a mail and web server at home for several years.

But I eventually said screw it - I was always a little uncomfortable leaving that equipment on 24/7 when I was nowhere around. It's one thing to take off for the day, but are you really comfortable leaving it on during a two-week trip?

When you leave consumer grade equipment running 24/7 for years you will encounter problems. I've had several disks fail, once trying to tear itself apart. Fortunately I never had a PS fire.

Then there's the separate issue of connectivity. Sometimes the cable modem would disconnect for no reason whatsoever. It's not hard to cycle, but you have to be there to cycle it.

Bottom line - I would look at virtual hosting at an ISP. I have a $25/month virtual system at <URL:http://tummy.com/>. It looks like my own dedicated system and I can run whatever servers I want - I have complete control. But I don't have to worry about the hardware or connectivity.

Re:Servers at home?

[dalemay]

My (friend at work had a house fire at his home. I went by his house the next morning and found the desk chair damaged, but most of the damage was when the firemen went in and started throwing out bedsheets pictures on the wall and other items out the window. I remember the funnist thing, his Dell computer bill(unpaid) was on the grass in the dew. Cause of the fire was not the outlet, but the sleepy wife sitting up late and dropping a lite smoke. UPS in this case, na.

Here are your main problems

[Roadkills-R-Us]

1) Many houses and apartments are not wired the way
      you think; all the outlets in one room may not be
      on the same breaker. Other rooms may have outlets
      on that breaker. Lights may or may not be on the
      outlet with that breaker. IOW, you would need to
      test thoroughly, and probably do some rewiring.
      And you still might miss something.
2) If you miswire anything and the house burns down,
      your insurance may not cover you. You'll need to
      check what the code is where you live and look into
      inspections. Getting a licensed electrician involved
      is a good idea.
3) You don't want to plug your vacuum cleaner into the
      output side of your UPS; not great for either one
      of them. Sooner or later, something like that will
      happen.
4) If you have a laser printer, startup surges can be
      huge; not a good idea to be on the UPS.

There are others, but this should be enough. I have
to go along with the people who receommended running
one (or however many) separate outlets for the UPS.
These can be current or new outlets wired to the UPS
and *clearly labeled*. Maybe use red covers or something,
with a label "Computer equipment only" or "Ask Fred
before plugging anything in here". Of course, you'd
have to change your name to Fred.... Depending on who
could possibly be plugging things in, you could even
consider switching to no normal outlets; hardwire some
power strips into a junction box, and bolt them underneath
the desks the equipment sits on. The biggest problem with
that is moving the desks.

And finally, what happens when you move? You need to make
sure this isn't too hard to reverse, or consider what
happens if you leave it. You don't want someone coming
after you with an axe or lawyer later.

Re:Here are your main problems

[kannibal_klown]

Many houses and apartments are not wired the way you think; all the outlets in one room may not be on the same breaker. Other rooms may have outlets on that breaker.

I can vouch for that. My house is only 3 or 4 decades old, and the wiring is all over the map. My bedroom, for example, has 2 outlets on 1 breaker and 2 on another. Keeping track of which breaker does which outlets is a real pain.

Heck, technically our house isn't up to code. It was shortly before they started demanding only 1 power box for the house placed in the garage; the reason being if there's a fire the firemen can quickly turn off the power before entering. I don't recall if this is a town/county/city/state requirement. We currently have 2 on opposite sides of the house, and someone told us if we ever sell we'd have to have an electrician set it up the right away.

I'd suggest to the original poster to just suck it up, buy 2 or 3 small consumer UPS's, and place one in each "computer room." Then, make sure the hubs/switches/routers are plugged into them as well as the PCs and monitors so if the power goes out you have have basic functionality plus a network.

Re:Here are your main problems

[Yottabyte84]

The firemen can use the whole-house breaker located at your meter, so I call bullshit on that argument.

Listen to me if you want to live

[unitron]

Do not touch your house wiring. The fact that you have asked the question which you have asked shows that you don't know enough to do it safely even if it were practical. Don't take this as a personal insult. Almost everybody who isn't an electrician falls into this category (not to mention some who are, allegedly, electricians).

It's almost certain that the wall sockets in the room are daisy chained with sockets in other rooms and all off of the same breaker. Same deal with the overhead lights. This makes your plan somewhat physically impractical.

If you are going to use this unit (the UPS), get the proper replacement battery or batteries. Do not even think of using automobile batteries or anything like that anywhere indoors. Do not think of using those types of batteries outdoors with a long cord running indoors to the UPS.

Get a licensed electrician to install a separate 30 amp circuit from your breaker panel to a single outlet in the room you have set aside as an office and plug the UPS into that outlet. Make sure that the UPS is working properly before going to the expense of installing the outlet.

Use the UPS to power your computer equipment (and perhaps a low wattage lamp), excepting of course any laser printers or the like.

As long as you're going to be talking to a real electrician you might inquire about the feasibility of setting up a generator and the necessary equipment to switch between it and the power company's wires. Unless you get a *very* large generator you'll need to have things set up so that the generator feeds selected circuits in the house (lights, refrigerator, wall outlets, but not the stove, the washer, the dryer, the water heater, the heat pump, etc.) while disconnecting the power company so that there's absolutely no way for the generator to feed power back into the power company's lines or for the power company to feed into the generator's output. Whether you get a generator that starts automatically and automatically disconnects the power company and connects itself, or one that has to be started and switched manually depends on how much money you can afford to throw at it.

You may want to look into swapping this unit (the UPS) for 2 or 3 lesser ones that can be plugged into your existing 15 amp outlets if you can find someone in the reverse of your situation. That way you won't need any special wiring (unless you go with the generator idea).

Been there, done that

[llefler]

I picked up a new (but old stock) APC 2000 a few years ago, and tried this solution until the batteries died. When it came time to replace them, I found it was much cheaper to just buy APC 1000s for each machine I wanted to stay up. My server will run for ~45+ minutes on it's UPS, and having a smaller (%) load on the system makes the batteries last longer. I ran the 2000 for a year with no problem, but by the end of 2 years the batteries were useless. I've been running the 1000 with my server for well over a year and no sign of losing capacity. For longer outages I bought a 5k generator, but since I bought it the longest outage has been 2 hours. Maybe it will work like insurance and I'll never need it.

One thing I would recommend, if you have the capability to do it, is run a separate circuit for your office. I did that when I replaced my service panel and haven't regretted it once.

Power strips

[DaRelliK]

Hook up power strips to the UPS outputs but beware about powerstrips not playing nicely with the generated square wave coming from the UPS when the AC line drops. Some fancy power strips see it as a voltage dip and spike and switch off to protect the equipment.

You should have no problem with running a small home office with a 3000VA UPS. I have two servers (mid towers), a gaming machine, 3com 24 port layer 2 switch, and a 3com pathbuilder s500 split between a APC 1500 RM and a APC 1400 RM XL. I would recommend getting the ethernet management card to go with it. It's nice to have it send pages when the power goes out, battery failure, etc.

Re:Power strips

[nmos]

Hook up power strips to the UPS outputs but beware about powerstrips not playing nicely with the generated square wave coming from the UPS when the AC line drops.

In general, a plain power strip is fine but anything that claims to be a surge protector can be a problem.

Arc Fault Interrupters -- better than GFCIs

[ankhank]

Consider this and dig through the Fire Marshals web site for a lot of interesting info on fires caused by consumer electronics.

A GFCI detects faults _to_ground_ but will not trip to stop a little arc between hot and neutral that can still start a fire.

Arc Fault Interrupters are new technology. Know about this stuff, it's significant.

[PDF] NASFM Science Advisory Committee Recommendations Regarding Arc Fault ... Typical conditions where arc faults may occur include damaged wires by ... The most serious of these conditions (in terms of arc-fault related fire risk) ...

www.firemarshals.org/mission/residential/ignition_ sources/docs/Doc.pdf

Winston Churchill would spit in your eye, wanker

[Anonymous Coward]

It's kind of embarrassing really, I keep needing to apologise for my nationality more and more lately. I meet Germans and feel the need to apologise for MY nation's conduct in the war...

Sod off, mate. You are a worm. What a disgrace to the name of "Englishman."

I will never apologise to the Jerries for anything.

On top of that,

[wsanders]

Connecting the UPS in any way that might possibly allow the output to come in contact with commercial main power ("backfeed" into the mains) could result in an explosion and fire. It could also kill a utility worker, although utility workers are trained to expect this when working with outages (and they fill fix the problem by grounding your backfeed, which will knock you offline or worse.)

Any competent electrician can install a transfer switch for the branch circuit, but you will ne astounded as the cost vs. a couple of power strips.

PV incentives

[falconwolf]

It's only worth it in California, really. Few other states have the incentives or the climate to make this worthwhile.

Here's a table of financial incentives by state. It lists them by Federal, private, state, utility, and local incentives. While pv may not be practical in some locations there are a number of financial incentives available that cover more than just pv.

Falcon

wind farms

[falconwolf]

We have a new wind farm being built in Wisconsin

Next door in Minneasota, we have a number of wind farms producing megawatts of energy. The Minnesotans for an Energy Efficient Economy has a good website about the state of wind farms in MN.

Falcon

Re:Just go PV ... or fusion

[pbhj]

Unless you can get that small Wisconsin roof to undergo spontaneous nuclear fusion ... then I think you'd get a bit more out of it!!!

Just harnessing the damn power is the clincher.

Surge strip warning!

[Anonymous Coward]

Due to the odd output from many UPSes you may want to reconsider a surge strip with any kind of power filtering on it... at least with my old APC Back-UPS 500 it specifically warned that using one would damage the unit / void the warranty.

A surge strip without protection would be ok, though.

Re:Just go PV ... or fusion

[RingDev]

Fussion exists. Heck the guys down at the UW are playing with it. The problem with Fussion is that it takes almost as much power to get to atoms close enough together for strong forces to take over. It's not economically sound. We'll see what the french can do though.

-Rick

Awfully timely...

[Pii]

Who'd a thunk it.

The article doesn't mention the technology that these new plants will utilize. I certainly hope they're planning on pebble-bed...

You don't need UPS

[Anonymous Coward]

sure its convenient but it is a waste of money for most people.

Re:Winston Churchill would spit in your eye, wanke

[David Horn]

You find it tough to take a joke, don't you?

I can't remember where I quoted my last comment from (think it was Red Dwarf), but then again England does need fewer patriotic and nationalistic wankers like you.