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Home Generators (or How DTE Energy Ruined My Holidays)
We are among the thousands without power in the northeast. Day four actually, and we've decided to look into generators so that next year's New Year's doesn't involve fears of frozen pipes bursting and hypothermic babies and cats. At the very least we just need enough juice to run the furnace blower, but if we're going to lay down the cash I'd like to know what it would take to get a little more power ... like enough to run a fridge, router, laptop and lightbulb. I know nothing about this sort of thing, but figure there are more than a few experts out there so I call out to the wisdom of the mob. What am I looking for? How difficult is the wiring? What will it cost me? On the extreme edge, what would it take to get off the grid entirely? (And on a side note, thanks to DTE Energy for telling us we had power when we didn't, for losing the ticket for our neighborhood, for telling us it would be back every single day when it wasn't, and for the helpful DTE representative who warned us that our pipes might burst. Thanks.)
At a minimum, you need:
Even though a furnace doesn't pull a lot when running, at the time that the blower starts up, there can be a VERY large startup current. The fridge the same, to a lesser extent.
You can get a lot fancier than this, but this will function perfectly as long as you are there to do the switching soon enough after power fails that your building doesn't get too close to pipe-freeze (I wouldn't want to go below 40 degrees f, pipes are often in walls that are cooler than the rest of the house.)
If that won't do, you're looking at an auto-start system with an auto-generator switchover, and the only thing I can tell you about that is prepare your wallet for deep excavation.
I've fallen off your lawn, and I can't get up.
Might be best to turn off the water entirely and drain the pipes rather than risk a burst.
The most rabid believers in American Exceptionalism are the exact same people whose policies are destroying it.
A lot of people in cold climates have backup (or even primary) wood stoves for heat. The main problem is that these have electric fans to blow super-hot air from around the stove's inner box into the room. Now, given that it's cold outside when you're building fires and very hot inside the stove itself, is there some way to directly convert the heat difference into enough electricity to drive the stove's fan?
Seriously, these things can potentially put out tremendous amounts of heat, probably enough to keep the pipes from freezing in a medium-sized house and certainly enough to cook simple foods. I'd think that a self-powered version would be extremely appreciated.
Dewey, what part of this looks like authorities should be involved?
I just built a new house, and had a 20kW Generac air-cooled generator installed along with a 200A automatic transfer switch and buried 1,000 gallon propane tank. It can run on propane or natural gas, and is manly enough to run my whole house. I have heat pumps with backup propane furnaces. The outside units are small enough so that I do not have to sequence the startup of the compressors, but I could do that if necessary (and may anyway). It self-tests once a week. All told, minus the tank (since many/most of you will have NG service), about $8,000 installed and tested. Well worth it for totally automatic, no-worries switchover even if we're away.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
Bottom line: Permanent home backup generators can be purchased for $3000 - $6000 + installation labor.
If you have natural gas available then I highly recommend using it for your backup generator, since outages are very rare and you won't ever need to worry about storing fuel.
If you house is like most, then your incoming service is 100 amp/220 split-phase. This means that a ~22 KW generator would give you 100% backup, but really most people don't use more than 80% of their service, so this setup should provide full capacity backup for almost anyone. If that's not enough, then move up to the 30 KW model. Kohler makes generators big enough to power your entire neighborhood if you are willing to buy it.
Wiring is not difficult, but depending on your experience level and your desire to obey the local electrical code, you should consider hiring a licensed electrician.
There's a dirty, and illegal way to do it.
First, if you follow these instructions, remember this KEY STEP
TURN OFF THE MAIN SWITCH. Also, NEVER turn that main switch on if the generator is running.
Finally, the main switch MUST be double throw.
Forget to follow these instructions, and you can very easily kill a lineman or blow up your generator.
Anyways, you just need a three pronged dryer plug, 2 of them, and sufficient length of heavy gauge wire. You create an illegal male - male 3 pronged plug, and connect your generator socket into the 3 pronged plug in your house used for the clothes dryer.
The reason it is illegal is because this form of installation does not prevent you from connecting your generator to the wiring outside your house. If you left the main switch on, you can energize the dead lines outside with 12,000 volts and kill a lineman.
The advantage? As long as the main switch is double throw, and you don't turn it on when the generator is connected, it is pretty safe. And cheap : a double throw switch and circuit box is $200-$500, while this method can be done for $10.
The first thing you want is a natural gas powered generator, not gasoline. Nothing like having to take a trip to the local gas station (presuming THEY have power) to fill up the generator every 8 hours or so. This, by definition, will make the generator a stationary unit (not on wheels, designed to be bolted down to a concrete pad).
Next, you want a generator with auto-start, auto-transfer with manual return. You want the thing to automatically kick in if the power dies, but YOU should be in control of when it decides to return to the grid. Nothing like finding out that the power died 10 minutes after you and the family left the house for a couple of days and coming back to a cold house with no power and potentially burst pipes.
Wattage - you will want at least a 5000 watt unit for whole-house use. Forget this idea of running power cords everywhere - unless you like the idea of tripping over power cords everywhere. With the transfer switch mentioned above, the generator takes the place of the grid so your internal house wiring will continue to serve it's duty.
There are several manufacturers of house generator systems. You can find low-end units at places like Home Depot or Lowes. Better units are best obtained from an electrical wholesale house.
Do yourself a huge favor here and hire a licensed electrician to do the work. It'll get done right the first time, the electrical inspector won't get excited (in a negative way) when he sees the work, and the odds of "something going wrong" go way down.
From another guy in Michigan (Westland)...
Ron Gage - Westland, MI
If you get the chance to move out, consider getting a Passive House, where it has super-thick insulation and is hermetically sealed. You wouldn't have to worry about frozen pipes in that kind of setup.
http://www.nytimes.com/2008/12/27/world/europe/27house.html
/.'s 10 Millionth
When you wire in your core devices that need continued power it is good to use a set of automatic transfer switches. When the grid power is up the electricity flows like normal, but when the generator us up the switches divert the inputs for those devices to the generator. When your power comes back up you simply turn off the generator and everything goes back to normal. If you buy the expensive whole house generator models they should come with this equipment, but you can buy them at your local hardware store, or eBay, for the low end generators. Having everything pre-wired saves a lot of fumbling around in the dark playing with kinked cords and potential high voltage, and a lot fewer headaches. No more pulling all refrigerators out just to plug them into the generator any more. Been there, done that. What I have that needs power has it as soon as I turn the key and pull the cord.
Every state and town has different rules about how it all needs to be set up.
In some places, like Massachusetts, you can't do any of the install yourself. You have to have a licensed electrician do it.
As a tip, get a generator that uses an inverter. They run quieter and are less likely to damage electronics if you run out of fuel with them.
You also, pretty much everywhere, have to have a proper transfer switch to disconnect the grid power any time there is any electricity being sent into your house by the generator -- otherwise you will energize the power lines around your house and could kill a line worker.
But generally, you really need to talk to someone who knows the answer locally for you.
Just a comment - we've had a Kohler 15kW Natural Gas powered generator that automatically comes on if power is interrupted for more than 10 seconds for the past year. We've needed it a couple of times now for multi-hour interruptions and it's worked well with the following comments:
1. Get an electrician that knows what he's doing and has experience with automated generators. I spelled out how everything was supposed to be wired and the bozo our contractor hired didn't trust my work beforehand and refused to wire up things like our refrigerator because he thought it drew too much current and then didn't believe my calculations
2. When you look at different generators, you will see that going to a water cooled unit (which is generally what you get when you are in the 22kW range) doubles the price. The 15kW units don't power the whole house, but more than enough to be liveable - you should get your Furnace, Air Conditioning (power goes out in the summer too), kitchen, basic computers & internet service, a couple of bedrooms and a TV/etc. working comfortably
3. The generators need maintenance. Plan on $500 or more a year - you can't do this yourself unless you are licensed for working around natural gas.
4. The units will test themselves once a week. Make sure they come on when nobody's going to be bothered
5. Don't try to do it yourself, the installation is somewhat expensive ($1,500-$2,000) and then you have to do the interior wiring (hooking up the Automated Transfer Switch (ATS) and deciding which circuits should be used).
6. The pricing of the units change during the year and what's going on. Right now would probably be the worst possible time to buy one - I wouldn't be surprised that their prices haven't doubled in your area. You should be looking in the late spring before hurricane season is the best.
myke
Mimetics Inc. Twitter
They are very reliable, and like you mentioned they are SIGNIFICANTLY quieter than the competition. If you have to have it rumbling overnight, the difference may be enough to warrant spending more. Also, be careful with power ratings, as they can be PEAK or MEAN. A 1kw honda could probably push >0.8kw all night. A 3.5kw (peak) no-name brand may not actually be able to do that.
I recommend Honda because a number of people I know have recommended them highly. Ultimately, that's my major source of information, as I do not own one myself.
Generac (http://www.generac.com/Default.aspx) sells complete packages ready to install as well as discrete units and transfer switches. I have one of their 15KW air cooled LNG/Propane generators (only in my case it is for power outages caused by Hurricanes). Very easy to install, mount their transfer panel next to your main breaker panel and transfer some of the loads from the main panel to the generator panel. The unit WON'T run your entire house, but you can put the most important circuits under backup.
If you have piped in LNG this is the way to go. Otherwise you need to bury a 250 to 1000 gal propane tank in the backyard.
The choice of fuel for generator use would be LNG, Propane, Diesel, and Gasoline (in that order).
Gasoline has the shortest 'shelf life' and is the most difficult to store (ask your fire department!).
Diesel fuel can last for years with the right additives and can power your car (if you have a diesel car). Diesel engines will also run on JetA (live near an airport?), home heating oil (filter it first!), bio-diesel (rob your nearby McDonalds of their used french fri oil!), even Kerosene. If you buy diesel fuel for generator use make sure you fill out the required paperwork so you don't have to pay the road taxes on the fuel. You can store diesel in the same kind of tanks that home heating oil is stored in.
There's two ways: the "emergency only" way and the fancy everything automatic way.
#1: Any gas generator with a 240/120v twist lock outlet plus one of those 6 to 10 circuit generator transfer switches. The transfer switch has rocker switches on it and you pick your favorite circuits that you want to run on the generator during an outage. It wires in next to your breaker box - no need to run new wire anywhere. They usually have watt meters on them, too. When the power goes out, plug the generator into the transfer switch, fire it up, and switch the circuits to emergency. Get a generator in the 5 to 10 kW range. Cheap and effective, but the downside is you have to start it manually, and most portable units you can find run on unleaded gas. Make sure you run the generator at least once a month or you'll be in a world of hurt when you need it the most and it doesn't want to start.
#2: The fancy automated way. Get one of those Generac whole-house units. They have automatic transfer switches that completely bypass the utility feed and run the whole panel. When the power goes out it auto-starts and auto-transfers. They automatically start to exercise every week, too. These will probably be special order and definitely more expensive, but well worth it if you frequently have extended power outages with crappy weather and you don't want to go outside to fire up the generator. They can run on natural gas or propane. Get at leat a 10kW unit.
Either way you go use a transfer switch that wires into your breaker panel. It's much easier than running new wire or extension cords everywhere, especially when the power is out and you just want to get the damn thing running.
this is my sig
Disclaimer: Electricity is dangerous, and can kill you. I am not an electrician. I am a slashdot poster.
The short answer for going-off grid: Buy lots of solar panels, which don't work as well here in SE Michigan (WTF is with you calling Michigan the "Northeast"?) in the winter time, but may be enough to get you by in conjunction with a good sized battery bank, and be prepared to significantly change the way you use electricity.
As for the short / halfass way most of us deal with generator usage: Backfeeding (which isn't always regarded as the safest / smartest thing to do, since there are always idiots out there that will screw it up)
-Go to your breaker box, shut off the main breaker or breakers (the ones at the top of your box that say "Main".)
Congratulations, your house is now just a giant circuit of wires, not connected to the grid.
-Shutoff any and all non-essential breakers, especially those connected to heavy draws (You're not going to run your electric stove unless you've got a beefy generator). You may just want to kill everything, then try individual breakers on over time.
-Fire up your generator. If your 401k is where mine is now, you may want to do this indoors, in a confined space....If breathing is a priority for you (pussy), do this outside, a reasonable distance from your house.
-Using a heavy gauge extension cord (Not a "move a lamp" cord, think "run a heavy appliance / machine" cord), plug in to a nearby outlet.
Congratulations, you are now "backfeeding" your house off the generator. Instead of coming from the power lines, your electricity is coming in through an outlet. *DO NOT TURN YOUR MAIN BREAKERS ON!!!* One, Your poor generator will now try to power the entire grid, something that no dinky little 2500watt Honda can do and two, you will send power down a line that the poor DTE linesmen will / may assume is dead. Improper backfeeds can kill (and usually do a few times a year).
Now you try and figure out what "side" of your box is being feed (if you have a typical, grey box with switch type fuses in two columns. If you have glass fuses in a quaint old house....call an electrician and move out. Oi). The breakers on the same side as the circuit your generator is plugged in to will now have power. If it's on the same side as your furnace, you can turn the furnace breaker on and, hopefully, the furnace should kick on and begin heating the house. If your furnace is on the other side as your power source, you can move the power line to an outlet that is on the same side, or plug in another extension cord from your generator to an outlet on the same side.
Once power returns to your area simply shut down your generator, unplug your cords, then turn your main breaker back on.
You have to prioritize what's important to you for power. Furnace and sump pump are your musts, and a sump pump can put out a very heavy load for a very short time, causing a brownout. Ditto a Refrigerator. After that, its your call based on what the generator will power. You can try to power your whole house on a 2000 watt generator, and the generator will run. You'll also kill the generator and probably damage your major appliances. Bigger the generator, the more you can power, and the greater the cost. Honda is the Sony of the Generator market. Generally quality stuff, but you'll pay for it.
You'd also do well to investigate your electrical box and spend a day labeling every breaker and determining what you have running on each circuit. (lest you find out that a cheap alarm clock shorted out while you were on vacation, causing a breaker to pop, and that breaker was the same circuit your sump pump is on, which explains why your basement is now a swimming pool.) When I moved it, my box had two labels "Furnace" and "stove", now all 22 circuits are labeled, and I've been putting together a diagram that covers every outlet in the house.
There are some people that if they don't know, you can't tell 'em.
Make sure your mains switch is double throw; some just open the live side. If this is the case, the guy who is trying to patch your power lines back together will die when you fire up your generator. Power companies get snarky about householders killing their staff.
[FUCK BETA]
Sorry to be Captain Safety, but I just want to point out the obvious: 1. Be very careful when using a generator - they produce lots of carbon monoxide and kill several people a year. Don't run them in an attached garage - even with the door open. 2. Only a qualified electrician should make the kind of wiring changes that are required to add a generator to a house electrical system. The building code requirements are complex, but more importantly, the potential for a fire that would burn down your house is very real. Personally, I'd rather go without electricity for a few days than either die from carbon monoxide poisoning or have my house burn down. Enough with the doom and gloom - adding a generator to a house electrical system is done frequently and generally isn't exceptionally complicated. It's worth it to hire an experienced, licensed, insured electrical contractor to do it right.
John DeArmond has a good article on his site about the $100 1KW Chinese-made generators sold at Northern Tool.
http://www.johndearmond.com/2008/12/24/the-generator-that-could/
Enjoy,
OZ
enough is too much
... The things get pretty darned LOUD tho....but, I've heard that the Honda ones...at a premium price, and very, very quiet....
If you put the generator in a hole in the yard, you'll have a night-and-day difference in noise levels. Just make sure that it is well-drained and set up so that no one will fall into it. Under the deck or patio is often good.
Beta is broken and the link to classic doesn't work. Stop wasting our time or there won't be anybody left here.
CAUTION: YOU MAY KILL SOMEONE IF YOU DO NOT TURN YOUR HOUSE'S MAIN BREAKERS TO OFF!
* If you leave the Main Breakers ON you will backfeed power to the entire neighborhood, and the power workers think the lines are dead. Very bad.
* Technically, you need an electrician to wire a breaker/cut-off switch to the generator. In this manner when you switch the generator connection to ON you also switch the Main Breakers to OFF. Expensive, but safe and complies with NEC.
* Most people just use a male to male plug, plug one end into the generator, and the other into some house outlet. If you turn the Main Breakers OFF ~BEFORE~ you do this, it is possible to get power to everything in your house, limited by the breaker capacity and the power generation capacity, and not feed the neighborhood. The relative safety of this is up to others to argue.
* IF THIS MAKES NO SENSE TO YOU, SEEK PROFESSIONAL HELP. Or at least a neighbor with a subscription to Popular Electronics. Your local linemen will thank you!
After you turn off the main breaker, put a padlock on it. This prevents anyone who "wants to be helpful" or "knows what they're doing" from turning your main breaker back on.
Also note that your house probably has two phases. With this approach, you probably need to wire them together. If you do this in the house breaker box, do it before you connect your alternate power. Note well: Anything that depends on 220 V power is unusable with this approach. That may well include the high settings on an electric range.
We did this for three days in a winter storm when I was a kid (neighbors were on the corner and had power up a different street; they ran us an extension cord). These tips I learned from watching what my dad did.
Look at the warranties for 'Whole House' backup power generators before buying. I got a Kohler 17KW natural gas/propane and automatic transfer switch with a 5 year full guarantee (Mine is natural gas, but an orifice change is all that's needed to run it on propane). And it's really quiet. It sits outside my bedroom wall and it's little more than a bit of a hum (easy to sleep through). But it was expensive to buy and install, and it's expensive to run, but when you need it, it's very appreciated. 17KW will handle most gas homes, but if you have all electric you better be looking at 25KW+. Those have small car engines in them (liquid cooled) and they REALLY suck up the gas. NOTE: Assume 150 hours to an oil change and 300 hours for plugs, so if you are expecting to be out for a week or more you'll need extra oil, oil filters and possibly a couple of extra spark plugs.
It depends on what tank you put with it. :) I don't see a spec for the tank on either the Home Depot site, nor the Guardian site. It does indicate that it runs on LP or natural gas. I would guess the assumption is that you can use it with your local supply, assuming you're in an area that you can get gas.
I have a neighbor a few miles away that has natural gas at his house. Now, I don't know if that's affected if the power to the area goes out.
The indicated fuel consumption at full load is:
Natural Gas - 139 cubic feet/hr
LP - 68 cubic feet/hr (1.68 gal/hr)
A 20 pound tank, like you'd use for your BBQ, is approximately 4.1 gallons, or about 2.4 hours.
A 250 gallon tank would last you for about 6 days.
A 500 gallon tank would last you for about 12 days.
According to These reports you'll be paying about $3 to $4 per gallon. This will vary by your location, current market value, etc, etc. If you were to need to run a week on propane, because of ... well, whatever ... It will consume approximately 280 gallons of fuel, and cost you pretty close to $1,000.
Now, if you fill the tank once, and only need a few hours here and there, then it's not a big deal. Just have it topped off every so often. How important is your power to you though? Can you get away without a computer, and camping around the fireplace? It's probably cheaper. :) The kids will make noise without the TV and PS3/Xbox360/GameThing(tm). Can you survive? Maybe they'll have to communicate. If they get too noisy, throw them out in the snow. They'll shut up just to be able to stay inside. :)
Serious? Seriousness is well above my pay grade.
You're comparing apples and oranges here. In your example you have a low rated wire with a higher rated circuit interrupt. A load that exceeds the capability of the wire will cause it to melt rather than tripping the breaker.
The generator in the parent is a power source, not a power draw, and the circuit interrupt is rated lower. If the power draw from the house is higher than 15 amps, the the circuit will trip disconnecting the draw from the source. Any reasonable generator will throttle back based on load. I don't see how this is different than your primary source, the transmission lines, being capable of considerably higher current than your house mains.
While I personally would want the wiring and transfer switch rated higher than the generator, I doubt it's the invitation to calamity that you imply.
It is amazing what you can accomplish if you do not care who gets the credit. -- Harry Truman
Burn the furniture. When that runs out, burn the neighbor's furniture. As far as that goes, a good house bonfire does wonders for keeping warm, even if only for a little while. Your neighbors may not appreciate it, especially if they're home. :)
Serious? Seriousness is well above my pay grade.
I have a neighbor a few miles away that has natural gas at his house. Now, I don't know if that's affected if the power to the area goes out.
Natural gas runs without electricity. Gas utility service runs at negligible pressure (3 psi nominal, down to 0.5 psi functional), so the available pressurized storage (gasholders, underground, or line packing) is unlikely to run out in the absence of electricity.
If a job's not worth doing, it's not worth doing right.
Thankfully, I don't have any "main" breaker whatsoever, so there's no risk, yep.
An approved transfer switch or interlock is the ONLY legal way to connect a generator, if you also have utility power service.
If you ever think you have to turn off the main breaker to prevent a backfeed, you are making an illegal connection.
Also, there is no guarantee that a breaker prevents a flow of current from OUTPUT terminal to INPUT terminal. Most breakers can without damage to the breaker, in practice.
But plug-in breakers are popular, these are not sufficiently secured.
I usually cruise /. for useful information, but this subject I know frontwards and backwards and there's a LOT OF BAD ADVICE BEING GIVEN.
Talking about 200 amp transfer switches is a dead giveaway that you're talking to someone who has seen it done once somewhere, but has not theory.
Talking about building a shed outdoors means they're not familiar with cooling requirements.
The Honda eu3000i has a remote start option. It's about 80$ for a reasonable size transfer switch, with instructions, from Home Depot or similar.
You can have a male plug dangling from one side of the transfer switch. By definition, it will not be hot, ever, unless it's plugged into the generator.
The purpose of the transfer switch is to isolate the power lines from the generator, and to allow the house to look like a single appliance.
It is a felony that will be prosecuted to connect your generator to the power lines, not to mention that: if the power comes on, the surge between your out of phase generator and the powerlines will likely hurt your generator, which is trivial compared to getting arrested for manslaughter for killing a power line worker.
There is a natural gas carburetor kit available for the eu3000i, so if you have natural gas, you have house heat and electricity, perhaps three times as cheap as gasoline. I've worked out the figures, and at the current natgas costs, the generator is almost as cheap as grid electrics.
You can do it yourself, using $/Btu for gasoline and natgas as the apples to apples comparison. The Honda is extremely quiet and cleanrunning and cools the muffler with the motor/generator airflow. It does produce carbon monoxide, so be sure to completely isolate the generator exhaust airflow from any possible air input to the house, like doors, windows, or leakage from the basement.
Put it outside, use a big chain through the handle. It only weighs 70#. It's really a gas engine with a huge alternator built into the flywheel, that puts out rectified AC to an ultracapacitor that's tapped by a 3Kw inverter as needed. The charge level of the capacitor determines engine speed, so it doesn't waste gas running fast when load is low.