120v generator to 240v transfer switch

[dseg]

I currently have a Champion 3400w RV generator and want to pair it with a 310CRK switch to power two rooms in my house. I know the switch overkill but I'll probably end up utilizing it more with a bigger generator in the future.
Since my generator doesn't have a 240 outlet and only has a RV 120v 30A TT-30R. Can I just buy this adapter and connect the generator to the switch to power a few 15-20amp breakers?
They are mostly lights and a refrigerator but usage wouldn't go over 3,100 watts.

 

[Bert_]

Looks good. The only real concern is that you don't overload a neutral somewhere that is sized for the imbalance of two opposite 120v lines. I doubt that would be a problem though.

Nothing wrong with a switch panel that's a little overkill now. At least it won't be a limitation in the future.

 

[dseg]

Thanks for the feedback. How would I overload a neutral somewhere that is sized for the imbalance of two opposite 120v lines?
If you could dumb that down, that would be great lol
Is there something I should watch out for?
FYI - the two hots on the L14-30R are being jumped from one hot 120v.

 

[Bert_]

A multi wire circuit would be the only problem.

The photo shows a multi wire circuit we'll say it's a 15A circuit with #14 wire, normally the red and black have 240v between them. Say you have 15A on the black wire and 10A on the red, the neutral would only carry 5A.

Now say the red and black wires are fed from the same phase, like with your 120v only generator. Rather than subtract now the neutral current adds. Using the same 15A on black and 10A on red, the neutral would now carry 25A.

 

[theoldwizard1]

I currently have a Champion 3400w RV generator and want to pair it with a 310CRK switch to power two rooms in my house.

Why not use a generator interlock on your existing panel ? It would be a lot less money.

 

[theoldwizard1]

A multi wire circuit would be the only problem.

Not that I have a lot of experience, but I have NEVER actually seen a multi wire branch circuit installed in any house. It could be simply because of their age or ???

 

[Bert_]

Not that I have a lot of experience, but I have NEVER actually seen a multi wire branch circuit installed in any house. It could be simply because of their age or ???

I don't run many in houses since they now require a handle tie. Seems like they were pretty popular in the 70's-80's. I've seen houses with a half dozen or so multiwire circuits.

 

[Frost]

I just installed a similar setup at my house this past fall.

I have the Champion 3100W inverter generator, and installed a Generac manual transfer switch, which is a 30A/240V switch with an included inlet and a generator extension cord.

In my case, the generator inlet is wired for both phases, but I modified the included 10ft extension with a 120V 30A cord end. In the transfer switch, I connected the one powered wire to both lugs in the transfer switch.

In my case, there are no multi-wire circuits in the house, so there is no issue with an overloaded neutral.

My goal with this setup was to be able to hookup a 240V generator in the future with fairly minimal rewiring, if necessary.

In the last power outage here, I found that I was able to power the furnace, fridge, TV/Stereo, and Kitchen/Living Room lighting with about 1000VA based on the gauge on the panel. The Champion 3100W did not rev up noticeably with this load on it.

For a total of about $1000 Canadian, I am very happy so far with my new generator and switch setup.

 

[EOC_Jason]

Sure, that seems reasonable... Obviously you wouldn't be able to power anything on that double-pole breaker because that would require 240V... But for now you can run all those single pole breakers just fine.

I currently have a Champion 3400w RV generator and want to pair it with a 310CRK switch to power two rooms in my house. I know the switch overkill but I'll probably end up utilizing it more with a bigger generator in the future.
Since my generator doesn't have a 240 outlet and only has a RV 120v 30A TT-30R. Can I just buy this adapter and connect the generator to the switch to power a few 15-20amp breakers?
They are mostly lights and a refrigerator but usage wouldn't go over 3,100 watts.

 

[Falcon67]

A multi wire circuit would be the only problem.

The photo shows a multi wire circuit we'll say it's a 15A circuit with #14 wire, normally the red and black have 240v between them. Say you have 15A on the black wire and 10A on the red, the neutral would only carry 5A.

Now say the red and black wires are fed from the same phase, like with your 120v only generator. Rather than subtract now the neutral current adds. Using the same 15A on black and 10A on red, the neutral would now carry 25A.

RE - Race Trailer with a 240V 50A box. 240V generator can handle 22A on each leg. Battery charger on one leg of a 240V generator pulls 10A, AC on the other legs pulls 13A. No problems. Splice same deal into your 3400W which is around 28A and you have a 23A load on the generator. Run a microwave to heat cup of water and your gen will kick the breaker.

 

[slow]

Inverter generator, Does it have a neutral/ground bond? What is the voltage from ground to neutral and power. I just checked my EU2000 honda, and it is 60 volts from ground to neutral and 60 volts hot to ground. I don't know what happens if you connect that to a bonded system.

 

[tyme2par4]

Not that I have a lot of experience, but I have NEVER actually seen a multi wire branch circuit installed in any house. It could be simply because of their age or ???

I have 1 in my house built in the early 70's. I believe they are just 2 separate outdoor lighting circuits though.

 

[ishiboo]

Not that I have a lot of experience, but I have NEVER actually seen a multi wire branch circuit installed in any house. It could be simply because of their age or ???

I put in a lot of MWBCs, because I figure it's doubling your capacity for not a lot more. Not much in the house, except in the basement and outdoor receptacles though. But in the barn/shop all my outlets are dual duplex receptacles, one on each leg of a MWBC.

If/when 12-4 NM becomes reasonable, I will be switching to that instead.

The key here is regardless of how often we see them, for this to be "safe" it has to be ensured that no MWBC is powered OR limit the entire circuit to the maximum of the smallest neutral on a MWBC, or 15A total to be safe.

I hate to be "that guy", but for feeding your existing house... a 240 generator is a no-brainer.

 

[dave*99]

Not that I have a lot of experience, but I have NEVER actually seen a multi wire branch circuit installed in any house. It could be simply because of their age or ???

My house had several MWBC's installed somewhere along the line before my ownership.

I have seen them in other houses. Often to feed kitchen counter receptacles.

I should add that these installations predate widespread use of GFCI's

 

[dseg]

A multi wire circuit would be the only problem.

The photo shows a multi wire circuit we'll say it's a 15A circuit with #14 wire, normally the red and black have 240v between them. Say you have 15A on the black wire and 10A on the red, the neutral would only carry 5A.

Now say the red and black wires are fed from the same phase, like with your 120v only generator. Rather than subtract now the neutral current adds. Using the same 15A on black and 10A on red, the neutral would now carry 25A.

Are multi wire circuits an issue if I just connect a transfer switch to a 240v generator with a L14-30R then?
Now I am worried I have a MWBC because (after Googling) it says to look for any double pole with 15-20 amps breakers. And I have one double pole for my dishwasher and sink disposal. My house was built in '96 but I am wondering if I have this multi wire circuit issue everyone is talking about now.
Also, what happens if there is an issue? Fire? Trip breaker?
Is there a way to avoid or know for sure if this is an issue for me?

 

[EOC_Jason]

Are multi wire circuits an issue if I just connect a transfer switch to a 240v generator with a L14-30R then?
Now I am worried I have a MWBC because (after Googling) it says to look for any double pole with 15-20 amps breakers. And I have one double pole for my dishwasher and sink disposal. My house was built in '96 but I am wondering if I have this multi wire circuit issue everyone is talking about now.
Also, what happens if there is an issue? Fire? Trip breaker?
Is there a way to avoid or know for sure if this is an issue for me?

Don't run your garbage disposal & dishwasher at the same time while running your generator...

 

[Falcon67]

Don't run your garbage disposal & dishwasher at the same time while running your generator...

At the track with AC, big battery charger, air compressor, microwave, toaster oven, lights, fans, computers, phone chargers and a small generator, it's called "budgeting power".

 

[theoldwizard1]

At the track with AC, big battery charger, air compressor, microwave, toaster oven, lights, fans, computers, phone chargers and a small generator, it's called "budgeting power".

Which is why I am such a big proponent of generator interlocks. If you overload the generator, there are 2 circuit breakers protecting it and the engine would probably stall anyway.

The point is, you don't have to GUESS which are the "important" circuit in your house. Why shouldn't you be able to turn on the bathroom light or even let the wife run her blow dryer. You just have to budget for the power that is available !

 

[EOC_Jason]

I meant it kind of jokingly for him not to run those two at the same time because that circuit is a MWBC in his house.

In reality those two devices don't use that much current and would probably be fine if both were going at the same time.