Generator Tripping with Manual Transer Switch

[JohnnyVV]

Hello everybody. My name is John and I’m a contractor who is stumped with an issue. I recently installed a reliance controls 10 circuit manual transfer switch (model 310crk pro/tran 2). The switch seems to be working fine when in line mode. All circuits to the house are fine and running ok. All 10 circuits are also single pole so no 240 needed. Client has a firman 4000W inverter generator (model.WH03242) with a standard three prong RV plug. Looking in the manual this model has a floating neutral so should be compatible with the switch. Client has a bridged adapter that converts to a four prong twist lock that feeds into the inlet box.

We fire up the generator, leave all in the line position plug in the electrical wire that goes to the transfer switch inlet into the generator and it goes into overload mode and cuts off all outlets to the generator. Have tried the same with the transfer switch in the off position and again cuts power. This generator is not gfci protected and all the circuits wired to the transfer switch are regular single breakers (no afci or gfci)

Does anybody know what can be causing this?

 

[ptonsparky]

Does it work when all the cords and adaptors are connected to the Gen but not the inlet of the transfer panel?

 

[Little Bill]

Get a 3-wire inlet and do away with the adapter.

 

[LarryFine]

I'd start with a basic troubleshoot looking for shorts/faults.

 

[Little Bill]

I'd start with a basic troubleshoot looking for shorts/faults.

Since the TS works with utility I don't think the fault/short would be in that wiring. The adapter is suspect in my mind as it trips the genny when it is plugged in.

 

[ptonsparky]

I'd start with a basic troubleshoot looking for shorts/faults.

Since the TS works with utility I don't think the fault/short would be in that wiring. The adapter is suspect in my mind as it trips the genny when it is plugged in.

Ditto & Ditto

 

[Todd0x1]

Floating neutral 120v inverter generators typically have the neutral at 60v over ground. When plugged into a transfer switch the N-G bond 'short circuits' the inverter and it shuts down.

 

[ptonsparky]

Floating neutral 120v inverter generators typically have the neutral at 60v over ground. When plugged into a transfer switch the N-G bond 'short circuits' the inverter and it shuts down.

Mine don't.

I pretty much have what the OP has described but my two small gens run in parallel.

 

[Todd0x1]

Mine don't.

I pretty much have what the OP has described but my two small gens run in parallel.

What make/model do you have?

 

[Todd0x1]

Mine don't.

I pretty much have what the OP has described but my two small gens run in parallel.

I just pulled out a Predator 3500 inverter generator, threw a meter on it and it has 60v neutral to ground.

 

[ptonsparky]

They are Powerhorse. Model IDK offhand. 1500 watt or in that area.

 

[Todd0x1]

They are Powerhorse. Model IDK offhand. 1500 watt or in that area.

Interestingly the manual for the powerhorse specifically makes mention of plugging it into a transfer switch (which tells me the neutral is not 60v above ground) and the Firman manual says nothing about plugging it into a transfer switch.

 

[ptonsparky]

I didn't think it was 60v. I did have old Genset that was though.

 

[synchro]

It might be possible that some generators show 60V to GND on both hot and neutral because the output has approximately equal capacitances to ground on them from internal filter capactors, but is otherwise floating. But I know that some 120V inverters (at least from the past) have an output transformer with a center tap to GND, and in that case you definitely shouldn't ground what would normally be a "neutral" terminal on the generator outlet.
I'd be curious if a very light HOT to GND load like a Wiggy was put on a Predator 3500 whether it would still maintain the same 60V.

 

[Knuckle Dragger]

Hello everybody. My name is John and I’m a contractor who is stumped with an issue. I recently installed a reliance controls 10 circuit manual transfer switch (model 310crk pro/tran 2). The switch seems to be working fine when in line mode. All circuits to the house are fine and running ok. All 10 circuits are also single pole so no 240 needed. Client has a firman 4000W inverter generator (model.WH03242) with a standard three prong RV plug. Looking in the manual this model has a floating neutral so should be compatible with the switch. Client has a bridged adapter that converts to a four prong twist lock that feeds into the inlet box.

We fire up the generator, leave all in the line position plug in the electrical wire that goes to the transfer switch inlet into the generator and it goes into overload mode and cuts off all outlets to the generator. Have tried the same with the transfer switch in the off position and again cuts power. This generator is not gfci protected and all the circuits wired to the transfer switch are regular single breakers (no afci or gfci)

Does anybody know what can be causing this?

You just received a lot of leads. If you can't figure it out, you should call a qualified electrician.

 

[Little Bill]

The inverter/generator in question is a 120V model and the OP is trying to feed a 240V TS with it. In using the adapter, from 4-wire to 3-wire, it's obviously creating a short and tripping the breaker on the inverter. Either need to get a 240V generator or connect the TS the proper way. OP doesn't appear to be an electrician or electrical contractor so I'm closing the thread as he has enough information to correct the problem without giving DIY advice on how to do it.