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

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.

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....

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.

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.

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.

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

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.