Onan output wiring

[Halffull]

I have a 6500 w Onan with 2 - 120 v 30 amp breakers. Is it possible to run the two legs to an electrical panel, then to a 240v to 120v step down transformer? My question is for two reasons. With only one leg being loaded, it seems to me that it's putting uneven pressure on the generator, and also the one breaker being used sometimes trips if the inverter is doing a bulk charge on the battery bank AND another heavy load kicks in.

[Halffull]

MrWizard wrote:
One more test
Check hot #1 to neutral #2
Hot #2 to neutral #1
Make sure those readings are 120v

Or maybe you already did

This will verified they are already connected together

Finally had a minute to do your recommended confirmation test. Result: Both hot leads crossed with both neutrals result in the same 125 volt ac reading.

Thanks again sir, looking forward to not tripping the 30amp breaker.

[MrWizard]

One more test
Check hot #1 to neutral #2
Hot #2 to neutral #1
Make sure those readings are 120v

Or maybe you already did

This will verified they are already connected together

[Halffull]

MrWizard wrote:
You are good to go
Just make sure that you also use both neutrals, that they get connected together (you did say neutrals, plural)
And the two hots together feeding one 50 amp breaker

Don't want to have just one neutral trying to carry the full return circuit load

Yes, 2 hot leads, 2 neutrals and one ground. Thanks very kindly Mr. Wizard, much appreciated.

[MrWizard]

You are good to go
Just make sure that you also use both neutrals, that they get connected together (you did say neutrals, plural)
And the two hots together feeding one 50 amp breaker

Don't want to have just one neutral trying to carry the full return circuit load

[Halffull]

MrWizard wrote:
sure wish i could get a look at the wiring diagram

IF that is the one i am thinking of you will read ZERO or near ZERO across hot lead leads 1 & 2 going to the (2) breakers

the generator is capable of 120v 54 amps, but you are trying to pull to much from one 30a breaker

IF it measures zero across the hot leads and 120v from each hot to neutral
you should be able to connect the hots to together with (1) 50amp breaker

the problem is me doing something i know how to test for and do correctly
and telling somebody else its OK ?

the hgjab-904 is an emerald microlite belt drive, not the model i'm thinking about
still if its zero volts across the (2) breakers
you should be able to replace with a single 50 and connect them together
as the are already connected internally
and that is key to the whole thing

I metered the leads this morning and as you suspected, the unit has 120v across the hot leads and neutrals and zero across the two hot leads.

[Halffull]

MrWizard wrote:
sure wish i could get a look at the wiring diagram

IF that is the one i am thinking of you will read ZERO or near ZERO across hot lead leads 1 & 2 going to the (2) breakers

the generator is capable of 120v 54 amps, but you are trying to pull to much from one 30a breaker

IF it measures zero across the hot leads and 120v from each hot to neutral
you should be able to connect the hots to together with (1) 50amp breaker

the problem is me doing something i know how to test for and do correctly
and telling somebody else its OK ?

the hgjab-904 is an emerald microlite belt drive, not the model i'm thinking about
still if its zero volts across the (2) breakers
you should be able to replace with a single 50 and connect them together
as the are already connected internally
and that is key to the whole thing

AH! Ok, now you're talking the language of my good friend. I'll pass your post along to him and get him to do the analytics next time he comes in to do some fishing.

Thank you very much.

[Halffull]

Chris Bryant wrote:
According to the ***Link Removed***, the HJGAB-904 is 120 volt only.
Any way you can separate the other loads while on generator?

All loads are fed by the battery bank/inverter. 75% of the time, the solar panels/batteries/inverter supply is sufficient to meet the load demands. Only over a period of heavy overcast days and/or when utilizing higher demand equipment does the generator get started. So separating out loads would be onerous and entail running much more cabling not to mention having to start the generator for some loads but not others. I guess my last question is: is there any way to take advantage of the 2 - 30amp breakers or are the two legs never to meet?

Thanks for you input.

[MrWizard]

sure wish i could get a look at the wiring diagram

IF that is the one i am thinking of you will read ZERO or near ZERO across hot lead leads 1 & 2 going to the (2) breakers

the generator is capable of 120v 54 amps, but you are trying to pull to much from one 30a breaker

IF it measures zero across the hot leads and 120v from each hot to neutral
you should be able to connect the hots to together with (1) 50amp breaker

the problem is me doing something i know how to test for and do correctly
and telling somebody else its OK ?

the hgjab-904 is an emerald microlite belt drive, not the model i'm thinking about
still if its zero volts across the (2) breakers
you should be able to replace with a single 50 and connect them together
as the are already connected internally
and that is key to the whole thing

[Chris_Bryant]

According to the this Onan spec sheet, the HJGAB-904 is 120 volt only.
Any way you can separate the other loads while on generator?

[MEXICOWANDERER]

My transformer supplier


sales@electricalsurplus.net

[MEXICOWANDERER]

I am not familiar with new Onan units.

Do they have spec plaques designating 240/120?

I can see center tapping a stator to obtain N and two Lines for a three wire output. In that case a transformer would be mandatory for single phase/neutral full nameplate output.

At one time TRACE ENGINEERING sold a toroid 2/1 transformer rated 4 Kw. continuous 5 Kw surge. Very compact and significantly cooler (efficient). Check with OUTBACK company.

[Halffull]

Chris Bryant wrote:
Unless it is an old unit, or a commercial unit, your Onan is a 120 volt genset, both breakers come off of one single winding. Is your rig a 50 amp or 30 amp rig?

As posted below, the generator is a year old and is used at a remote off grid fishing camp as backup to a solar/battery system.

[Chris_Bryant]

You may well be correct, but my main point is that the units do not produce 240 volt power- on the schematics I looked at the windings all go to a common terminal, which feeds both breakers. It all depends on the model, though.

[Halffull]

MrWizard wrote:
Somebody wired your breaker box wrong? What is the main in your breaker box?
Too much load on one side
It is most likey wired with all your loads on one side including one air
And the other side is only carrying the other air

Yes it could be reconnected for 230v but you don't need too do that
Just need to have a two line input breaker box, using both generator output lines
And balance the load distribution

The other question is the water heater on LP? What about the fridge?
When In hot weather using the genset and air, making sure those stay on LP manually is a good idea, so they don't switch over and use the Onan power

That Onan is big enough provided the loads are balanced

The unit isn't in an RV, it's wired ONLY into a 120v 2500 w inverter/charger which is backup to a small solar bank.