3 phase gas generator uses

[tawilson]

A friend just offered me a working generator. I can't turn down a good deal, even if I don't need it. But can I use this for 110 and 220 volt equipment? I think so, just checking.

[RonMar]

What are the specs on the genset?

Generator basics:
A single phase generator typically has 2 hot leads and a neutral/ground. Each hot leg(or phase) measured to neutral is 120VAC. One hot leg measured to the other is 240V. This is the same as what is run into the typical american household(2 hots, neutral and ground) and what most household power panels are built to distribute. A 10KW single phase generator as I just described can only deliver 5KW out of each 120V-Neutral connection. the distribution panel, like that used for the commercial power feeding your home must have the loads wired to the circuit breakers so that the two available legs are balanced to get full power out of the generator without overloading a single leg. 240V loads will draw their current equally from both legs so they are not a problem.

A 3 phase generator is similar to what I have described above except there is an additional hot lead/leg. Any of the 3 hot legs measured to neutral will be 120VAC, any hot measured to any other hot will be 240VAC. 3 phase power is typically used in industrial applications, particularly those that employ large horsepower electric motors. It will require a 3 phase distribution panel to get the full capacity out of the generator. You could wire 2 of the phases into a standard domestic panel, but the generators rated capacity is divided amongst the 3 phases. IE, a 15KW 3 phase generator can only support 5KW on each of it's 3 legs, or 10KW to a 240V load applied across 2 of the three legs. Because of this, a 3 phase generator needs to be a third larger than it's single phase counterpart to feed a typical domestic load. That means larger engine and greater fuel consumption for a given application. If the generator is Diesel powered, you may never be able to operate it near it's optimum loading using only 2 of the 3 phases. An underloaded diesel can have longer term mechanical problems and requires more frequent oil changes to deal with fuel oil diluting the lube oil.

[dqdave1]

check voltage output on generator; it could be a 208 volt, 3 phase generator.

[DieselPower]

It isn't by chance a surplus military generator is it? If it is, I have two surplus 10K and one 5K gen set's. All three are 3 phase. There is a master switch behind the gauge panel that let's you change from single to 3 phase and between a couple of different voltage setting's.

[tawilson]

It is. I'm looking for something to run my 220v air compressor and my 110v mig welder. I've got a 5000w Honda generator now, but it doesn't have enough beans to start the aircompressor. Sounds like this may do the trick. And the price is right. Thanks everyone.
Ronmar, that's about as clear and concise an explanation as anyone could ask for. Thanks. It is gas.

[DieselPower]

What size is it? I may have the manual for it if it does not come with one. I also know of lot's of places to get surplus parts for them in case you need anything like carbs, govoners, cylinder heads or even whole engines or generator heads.

[tawilson]

That's all I know about it till I get it. When I do, I'll post here, probably a couple pics too. Thanks again to all who responded.

[tawilson]

Finally got it. Here's a couple pics.

[schmism]

very cool! were do i get one!

[tawilson]

Knowing the right person is what worked for me. I guess there's a lot of these around in municipal or state buildings and garages. This one was mounted in a ceiling in one and the insurance inspector told them to get rid of it, so they did.