Electrical – use a 240/120 transformer and adapter cable to connect a generator to the house

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Tornado took out power around here for a good while. Parents aren't here and I'm stuck with the task of hooking up a generator. I'm not savvy with this stuff very much at all.

Here's the issue. The connection coming out of the house is L14-30P. The generator has L14-30R. In my head we just need a 30a cable between the two.

The only stuff we have right now is an adapter L14-30P to L14-20R. My dad says this adapter is needed because it puts the voltage down to 120v. It's literally just an adapter. He says at 240v it would fry our equipment and appliances in the house. Doesn't make sense to me to have this adapter, then have a L14-20P to L14-30R cord connected between the adapter and the house. Seems like an extra useless step right?

I'm not worried about breaker positioning and all that. I just need to make sure I have the cords done properly between the generator and the house. I've got the rest done.

Feel free to correct everything that is incorrect about what I just stated, logic and all.

Here is the front of the generator:
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Best Answer

It does seem like an extra useless step. The L14-30R on the generator has two 120 V slots, a neutral slot and a ground slot. The voltage between the two 120 V slots is 240 volts. If the L14-30P on the house is wired correctly, it is connected to both 120 and 240 V circuits in the house. However the generator is not big enough to power the 240 V appliances in the house. It is not even big enough to power very many 120 V appliances. It could be that the cord that you have does not have 4 wires. It may be wired to supply only the 120 V circuits in the house that are connected to one of the two L14-30P 120V prongs. If your dad has told you to use that arrangement and you have reason to believe he has used it in the past, I would say go ahead and use it. You may find that some things in the house will not turn on. If that is the case, determine if they are things that you can live without. If they are, that is your answer.