120v Generator, 240v Transfer Switch

[Sterlingcash]

Need some help here on using a 120v, 3500watt generator.

The setup: I live in a mobile home next to a larger house. The main power line feeds into the panel on the main house. On that panel is a 100amp breaker for the mobile home. There is a professionally installed 50amp transfer switch (reliance) on the panel. My landlord powers both units using a 10000watt generac unit, L14-30. We switch off the 240v circuits and the generator handles all other loads (5 refrigerators, 2 furnaces, etc) perfectly fine. The mobile home is 120v only.

My landlord has gone on vacation and I would like to power my mobile home using a more fuel efficient generator. Here’s what I have: https://generatorbible.com/generators/westinghouse/igen4200/
I bought an adapter to connect the TT30 outlet to the L14-30 transfer switch cord.

On the main unit panel, I have switched off all breakers except that running to the mobile home. However, power is not running to the unit. I only have two appliances plugged in (about 2400 starting watts). I understand only the very basics of home electrical systems. I can’t figure out why I can’t power the smaller unit with this generator. I’ve seen other threads on this type of setup, but have been unable to troubleshoot. Your help is appreciated.

 

[pattenp]

In picture it appears the interlock is slid left but the generator breaker is not turned on.

 

[Sterlingcash]

In picture it appears the interlock is slid left but the generator breaker is not turned on.

Thanks, I flip it on when the generator gets warmed up. Then flip it off just before shutting down the generator. The picture was taken after shutting it down, thus it’s off.

 

[wyliesdiesels]

You say the mobile is 120v only yet the breaker feeding it in the main panel is a double-pole 240v breaker and the disconnect breaker (50a) in the mobile home subpanel is double pole, along with the air conditioner. So the mobile home is definitey not 120v only.

So the most likely issue here is the single ungrounded conductor (hot) coming from the generator is powering the opposite phase to the double pole breaker than what the circuits you need powered are on. Meaning all your 120v loads in the trailer are on the opposite phase thats not being powered.

One way to fix this is to make a custom adapter that jumps the single hot condutor in the TT-30 to both sides of the 14-30. You wont have 240v as you know though...

 

[pattenp]

You say the mobile is 120v only yet the breaker feeding it in the main panel is a double-pole 240v breaker and the disconnect breaker (50a) in the mobile home subpanel is double pole, along with the air conditioner. So the mobile home is definitey not 120v only.

So the most likely issue here is the single ungrounded conductor (hot) coming from the generator is powering the opposite phase to the double pole breaker than what the circuits you need powered are on. Meaning all your 120v loads in the trailer are on the opposite phase thats not being powered.

One way to fix this is to make a custom adapter that jumps the single hot condutor in the TT-30 to both sides of the 14-30. You wont have 240v as you know though...

Yep.. I just responded to the same question on another forum thinking the same thing.

 

[Sterlingcash]

You say the mobile is 120v only yet the breaker feeding it in the main panel is a double-pole 240v breaker and the disconnect breaker (50a) in the mobile home subpanel is double pole, along with the air conditioner. So the mobile home is definitey not 120v only.

So the most likely issue here is the single ungrounded conductor (hot) coming from the generator is powering the opposite phase to the double pole breaker than what the circuits you need powered are on. Meaning all your 120v loads in the trailer are on the opposite phase thats not being powered.

One way to fix this is to make a custom adapter that jumps the single hot condutor in the TT-30 to both sides of the 14-30. You wont have 240v as you know though...

Thanks, yes I think this is the problem.

The mobile doesn’t actually have AC, the 30amp circuit on the left side of the panel doesn’t power anything (to my knowledge). All appliances, including the furnace are in the right side, 120v.

I will go ahead with the custom adapter.

 

[Sterlingcash]

You say the mobile is 120v only yet the breaker feeding it in the main panel is a double-pole 240v breaker and the disconnect breaker (50a) in the mobile home subpanel is double pole, along with the air conditioner. So the mobile home is definitey not 120v only.

So the most likely issue here is the single ungrounded conductor (hot) coming from the generator is powering the opposite phase to the double pole breaker than what the circuits you need powered are on. Meaning all your 120v loads in the trailer are on the opposite phase thats not being powered.

One way to fix this is to make a custom adapter that jumps the single hot condutor in the TT-30 to both sides of the 14-30. You wont have 240v as you know though...

Let me make sure I understand this. So there is one 120v hot coming out of the generator. It is only powering one phase. Since nothing in the mobile works, does that mean it’s powering the “AC” or left side of the panel? Or is no power going to the mobile at all?

 

[89MustangGX]

Not an electrician - but to my knowledge usually the buses will zig-zag back and forth, so if it's only getting one leg, I would think half of the panel would be powered. Unless this panel is different, I think something else is wrong. Might end up needing that custom adapter anyway, but I think I'd back it up a bit and make sure the generator is actually putting out power. Check the circuit breaker on the generator, use a volt-meter, etc.

 

[89MustangGX]

I looked up what I *think* is the adapter you are using (orange cord to go from TT-30R to L14?) and the ones I found indicate the hots are bridged together. That would eliminate needing any type of custom adapter. So I am more convinced something else is wrong. Either with the generator or the adapter. I'd check circuit breakers and reset switch on the generator and if you have a volt-meter check the outlet on the generator and then on the adapter and even the cord. It's possible the cord is not in the receptacle on the house all the way or something of the sort - that style needs to push in and twist to lock.

 

[wyliesdiesels]

Let me make sure I understand this. So there is one 120v hot coming out of the generator. It is only powering one phase. Since nothing in the mobile works, does that mean it’s powering the “AC” or left side of the panel? Or is no power going to the mobile at all?

NO, the phases in a panel alternate between the breaker spaces on both sides of the panel. since you may be only powering one phase leg with the generator (if the tt-30 to 14-30 adapter doesnt bridge the hot legs) then only breakers on that phase in the mobile home panel would get power.

Do you have a multimeter you could use to test power in your panel and on the generator output?

I looked up what I *think* is the adapter you are using (orange cord to go from TT-30R to L14?) and the ones I found indicate the hots are bridged together. That would eliminate needing any type of custom adapter. So I am more convinced something else is wrong. Either with the generator or the adapter. I'd check circuit breakers and reset switch on the generator and if you have a volt-meter check the outlet on the generator and then on the adapter and even the cord. It's possible the cord is not in the receptacle on the house all the way or something of the sort - that style needs to push in and twist to lock.

Depends on the brand and model. some bridge both sides and some dont.

 

[StillTooManyHobbies]

Thanks for this thread. Power went out yesterday and my gen's with 240 were down. I read this, had a spare L14-30 for the transfer panel and made a cord with the hots jumpered to plug into a 120v generator and we had enough power to get through the evening. Thanks again everyone.