"If I have one generator with a 120V/240V 50A outlet, and another generator with a 240V 50A outlet, what are the practical differences in wiring them to power my home??"
none.
i have the generac ultra source 15kw continous 22.5kw surge genset.
heres one dirty secret about generators that you should know. the 50 amp outlet is using a 50amp circuit breaker on the generators panel. this only allows 12,000 watts of power. (50x240=12000) so if you buy a 15kw generator youre paying for 15kw but only getting 12kw out of the 50 amp outlet. in order to get the full 15kw you would have to max out the 50 amp outlet and then plug in some other ---- to the other outlets on the generators power panel. thats a hassle. generator companys are very misleading when it comes to this. most people wouldnt catch this little detail.
the way around this is to replace the circuit breaker and outlet on the generator with one that is rated for higher output, which is exactly what i did.
by the way, a 240v outlet can power 120v appliances just fine. anyone telling you otherwise is full of it. i know because ive personally done it. all the 120v outlet is is half of the 240v outlet. you take the wires from the 240v outlet and use half of them for 120. dont believe me? open the power panel on the generator and have a look at the wiring.
so heres how i wired up my generator. i removed the 50 amp breaker from the power panel and replaced it with a 65 amp circuit breaker. (65x240=15600) this gives me the full 15,000 watts that the generator is rated for. actually its a touch over rated but thats ok. i doubt i even pull 10,000 out of this thing. i just dont like the idea of paying for 15000 and only being allowed to use 12000. i also upgraded the 240v outlet to one which can handle higher amperage. i forget the size though. i think its a 75amp outlet? cant remember for sure.
on the house end i bought a double throw double pole transfer switch. this is a special switch which has 2 positions. the first position is on-mains power. the second position is on-genset power. its designed in such a way that you cant have the mains and the genset engaged at the same time. this is a big safety item no house should be without. espically if youre ghetto wiring a generator like i did.
to connect the genset to the breaker box i added a 65 amp 240v breaker to an empty slot in the existing panel in the house and wired it to a heavy duty power cable with 4 wires of 6 or 4 gauge. i forget which. this cable has 4 internal wires, 2 for a/c hot and 1 neutral and 1 ground. on the end of the cable i put a plug in connector which fits the receptacle on the generator that i upgraded to handle more power.
when the power goes out i plug the generator in, fire it up wait a few minutes for it to warm up and then flip the double throw switch. the power comes on and all my 120 and 240v items work properly. i didnt use any generator sub panels or anything like that. i suppose you could if you wanted too but it greatly adds to the complexity of the wiring, and the cost. although it may be required for code.
keep in mind im not an electrician and if you are scared about working with electricity you probably shouldnt be doing it. for most people its probably nest to have an electrician install the generator. i dont want my advice to end up killing anyone but i believe the way i did it is very safe. at no point in time is any wires i own live and able to be touched or shorted out.
oh the other thing i did was to ground the generator via the ground wire in the 4 wire cable. i also drove a 6 foot copper pipe into ther ground with a hammer and attached a ground lead to the genset as an EXTRA ground using a wing nut *^*just in case*^* something were to happen. never know when lightning may strike.
