Generator recommendations
I am considering getting a generator as a back up power source for our home. I would need it to run the water pump for our well as well as the electric start on my oil forced hot air heating system. On top of all that I would like to be able to keep the refrigerators running and we also has an electric stove. What size generator would you all recommend? At Home Depot I saw a few in the 5000, 6000 watt range. Would they be big enough to handle my home power setup or should I go even higher into the 7000 range? Thanks in advance for your help. Roger
It is the start amperage that usually gets you. With that much to run probably a 15kw. Now if you want to go with a smaller unit you can use some isolation switching so that you don't have everything attached at one time. Dale
You don't use your main breaker to disconnect the generator from the primary power source. You use a Transfer Switch. The Transfer Switch is a double-throw switch. It can be set to either draw power from the utility or from the generator. The generator can never be connected to the utility, which keeps linemen from getting fried by your generator. There are two kinds of transfer switches, manual and automatic. If you just buy a 5kW Honda or something and bring it out when the lights go out, you'll want a manual switch. IIRC you can even get one with a socket for the generator, which makes going onto generator power easy. The automatic switches are computerized--what isn't?--and look for current on the utility lines. As long as it's there, that's where you're powered from. When the utility goes dead, the automatic switch fires your generator, waits until the power stabilizes then switches you to generator power. After the utility starts producing stable power, the automatic switch returns you to utility power and turns your generator off. The automatic switch also runs an exercise cycle for your generator; every so often it will crank your generator and let it run for a while just so you know it will start when it needs to. Hints for generator life (from an old soldier whose generators were survival tools): * Never buy a generator without an hour meter. * If you don't use your generator a lot, make sure to change the oil every year and every time you use it for longer than four hours. * If this generator is for emergency service, every three months you should start it up and run a tank of fuel through it. * Generators don't last if they're not loaded. You need to put some sort of a load on the generator when you're doing your exercises. My very favorite load is the 30-cup coffeemaker--they require a lot of power to run, they're something you might use for something else, and they're dirt cheap. Get one for every full 2kW your generator puts out, and hook them all up at once. (The standby generators Generac makes have a load resistor built into them, which they feed their power into if there is nothing connected to them.) * Another good way to exercise your generator: outdoor projects. If you're building a deck, playset or whatever, just use your generator instead of running cords from your house. * When you are in an emergency situation, the very first thing you must do is to check the oil. Next, write the reading off the hourmeter on the side of the machine with a Sharpie. Every time you run a tank of fuel through if you're running on the internal tank, or every four hours if you're on jerry cans, shut down the generator, let it sit five minutes and check the oil. If the oil level is going up, change it--oil levels go up because gas is getting into the oil, which happens and which is very bad. Change the oil every two weeks if you're on generator for that long--if you live in the hurricane belt, that can happen. And let the generator cool down one hour every 12. In the Army, units with smallish (under 30kW) generators always deployed with two generators and wired our load in through a transfer switch; we ran one can of fuel through the generator, switched generators before the fuel in the can ran out, and maintained the first generator after it cooled. You probably don't have two generators, but that's a good schedule if you do. I stipulate "under 30k" because 30k-and-larger Army generators are made to run a lot longer than the smaller generators are--they have big diesels on them that turn at 1800rpm, they use dry-sump oiling so you can check the oil level without shutting down (if there's some in the tank, you're good) and they're water-cooled. Those you can hook a 55-gallon drum of diesel to and just run forever. And as for the 100kW-and-up generators you don't get to see because there's a whole career field dedicated to them--those generators will literally run forever. I once saw a 300kW generator in Korea. This thing had two 1200-horse Detroit Diesel engines on it--one ran while the other sat. The man in charge of this machine had worked for the United States since the end of the Korean War, and this generator was all he'd ever done. About once a month, he'd crank up the second engine and switch the generator over to it, then pull maintenance on the engine he just shut down; the people who used the electricity couldn't tell when he did it, it was so smooth. I asked him if he ever had any downtime. Then I had to tell him what downtime was; "oh no, the generator has always worked." Partly because 16-cylinder Detroit Diesels are absolutely reliable, and partly because the operator treated this unit like he owned it. -- --jmowreader
There are a couple of reasons. The first is to prevent a phenomenon which has a really long name but which equates to "backing up." If you run a generator for a long time and it doesn't have a load, the electricity the generator makes will eventually "back up" and burn out the coils in the alternator. (Generators produce DC; alternators produce AC.) The other is really critical on a diesel but it's important on any generator. When you pull load on a generator, you will cause it to work harder--you can actually hear them slow down. Diesels CAN NOT be run without a load on them for a long period of time, because you'll damage the engine. On a vehicle, they use the engine accessories--the alternators, compressor and so on--to load the engine. If you have a diesel generator--Yamaha makes them--make very certain that you don't see heavy black smoke coming out of the exhaust pipe. I love diesel generators and if I were to buy a generator right now it would be a diesel, but I can't in good faith recommend that anyone else get one. -- --jmowreader High quality hot dogs come eight in a package. If you're wondering why hot dogs come in packs of 10 and buns in packs of 8, it's because you're a skinflint.
I hadn't seen gopower.com before. Thanks for the link. But look again...I was pointing out that diesels are never small generators. The smallest generator gopower.com sells is an 8k Mitsubushi for $6999. Hell with that, man, if you go just a little ways down the page you can find a 30k John Deere for $8999. When you have a 30k generator you don't have to set up little regimens--"make sure you unplug the freezer when you want to use the microwave, and never turn on the range"--because with a 30k generator you can run everything in your home. The really interesting one was on the main page: they have six 250k generators powered by 12-cylinder Detroit Diesels for $15,000 each. Why is this interesting? Because you could form a nonprofit corporation with five of your neighbors, buy one of these generators, install transfer switches on everyone's house and get an electrician to run underground cables from the genset to everyone's transfer box, and have a nice little emergency power company. -- --jmowreader High quality hot dogs come eight in a package. If you're wondering why hot dogs come in packs of 10 and buns in packs of 8, it's because you're a skinflint.