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Topic: Not switching to AC voltage with generator (Read 1842 times) previous topic - next topic
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Not switching to AC voltage with generator
My generator starts and runs fine however it's not switching to AC power nor are the batteries being charged.

I checked the circuit breakers and they aren't flipped.
Shore power works and charges batteries.

What should I check next?
2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #1 –
The circuit breaker on the generator.
Harry 2006RB
Re: Not switching to AC voltage with generator
Reply #2 –
The transfer switch on the back of the converter unit.

Steve
2004 FL
2013 Honda Fit
Re: Not switching to AC voltage with generator
Reply #3 –
Electrical path is Generator-->Automatic Transfer Switch-->Coach Power Center

Check the breaker on the generator, and then do your best to determine where the 120v power is and isn't.

If the generator breaker is on, I would be reaching for a non-contact voltage tester and checking the wires along the path for voltage.

https://youtu.be/wmeuTpZ1e0I?t=207

ATS: The Lazy Daze Companion: Automatic Transfer Switch (ATS)

Rich
2003 MB
Re: Not switching to AC voltage with generator
Reply #4 –
Quote from: hbn7hj  - 
The circuit breaker on the generator.

That was it.
It immediately switches to off when it tries to power on.
It is a 1995.
Could it be the breaker age rather than a short in the system considering shore power works fine?
😥
2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #5 –
Quote from: tedeboy  - 
That was it.
It immediately switches to off when it tries to power on.
It is a 1995.
Could it be the breaker age rather than a short in the system considering shore power works fine?
😥

Mine did it as well a few weeks back. Didn’t know about the circuit breaker on the generator until I read through the manual. Just ran the generator again yesterday and it switched over fine so it may just be something you need to check on occasion.
Greg & Victoria
2017 Mid-Bath  “Nocona” towing a manual 2015 Forester
Previously a 1985 TK
SKP #61264
Re: Not switching to AC voltage with generator
Reply #6 –
Quote from: HiLola  - 
Mine did it as well a few weeks back. Didn’t know about the circuit breaker on the generator until I read through the manual. Just ran the generator again yesterday and it switched over fine so it may just be something you need to check on occasion.


The generator AC circuit breaker switch won't stay on.
2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #7 –
Gotta be an easy (cheap) fix. Either the circuit breaker is faulty or the line is shorted to ground, possibly within the transfer switch.
Harry 2006RB
Re: Not switching to AC voltage with generator
Reply #8 –
Quote from: hbn7hj  - 
Gotta be an easy (cheap) fix. Either the circuit breaker is faulty or the line is shorted to ground, possibly within the transfer switch.

Thanks.
I have a Progressive Dynamics converter in it now. I assume it must have a transfer switch?

I think I'll start by replacing the circuit breaker.
2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #9 –
Tede, you will probably find the transfer switch on the back of the power panel. 

One BIG caution - do NOT EVER try to hold the breaker closed.  That is a really good way to start a fire.  Second big caution, do not try working on the ATS with power in the system.

Ken F in NM
'08 MB
Re: Not switching to AC voltage with generator
Reply #10 –
Quote from: Kenneth Fears  - 
Tede, you will probably find the transfer switch on the back of the power panel. 

One BIG caution - do NOT EVER try to hold the breaker closed.  That is a really good way to start a fire.  Second big caution, do not try working on the ATS with power in the system.

Ken F in NM

Thanks for those safety tips Ken.
I got the switch out.
I had the battery disconnected and the shore power unhooked.

Onan part #320-1323




2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #11 –
Quote from: tedeboy  - 
Thanks for those safety tips Ken.
I got the switch out.
I had the battery disconnected and the shore power unhooked.

Onan part #320-1323

Great, let us know if it solves the problem!
Greg & Victoria
2017 Mid-Bath  “Nocona” towing a manual 2015 Forester
Previously a 1985 TK
SKP #61264
 
Re: Not switching to AC voltage with generator
Reply #13 –
While your at it, with all the power off and the breaker disconnected check the leads with an ohm meter and make sure nothing reads to ground.

Jon
1994 MB
Re: Not switching to AC voltage with generator
Reply #14 –
Quote from: JonS  - 
While your at it, with all the power off and the breaker disconnected check the leads with an ohm meter and make sure nothing reads to ground.

Jon

A hooked the batteries up.
Should I disconnect them first?
2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #15 –
2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #16 –
Hi Ted;   There is a load relay in the converter that switches the 12 VDC part of the house to converter supply, instead of battery 12v. This only switches when the converter is connected to 120 VAC, and is producing 12Vdc. (really about 13.2VDC.)  This relay doesn't switch 120VAC, and isn't the bus transfer relay.   The Bus transfer relay, normally connected to shore power, has the time delay and switches to generator power, when the generator is producing 120VAC. You can leave the batteries connected to the coach. They aren't involved in 120VAC circuitry.  The PD converter's only involvement with AC is to take it from the bus transfer relay if it is available. If the generator isn't running, and shore power isn't connected, there isn't any 120VAC.
     If you have a whole house inverter, many times they can back charge the batteries when 120 Vac is available. It gets a lot more complicated. Unless you have a whole house inverter installed, it isn't likely to be a hazard.

     One way to test that Onan breaker is to hook it in series with the 'hot' black wire of a line cord, and see if it will stay on with a load like a table lamp.  If it doesn't, it is faulty. If it does stay on, then likely there is a short between 'hot' and neutral or ground, running to the bus transfer relay. The bus transfer relay could also have a problem. Do you have a 'surge protector' wired in somewhere?       RonB  
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: Not switching to AC voltage with generator
Reply #17 –
Quote from: RonB  - 
....

     One way to test that Onan breaker is to hook it in series with the 'hot' black wire of a line cord, and see if it will stay on with a load like a table lamp.  If it doesn't, it is faulty. If it does stay on, then likely there is a short between 'hot' and neutral or ground, running to the bus transfer relay. The bus transfer relay could also have a problem. Do you have a 'surge protector' wired in somewhere?       RonB  

No inverter and no wired in surge protector.

There are two black wires going to the breaker switch I removed. Not sure what you mean "hook it in series".

Thanks for the help RonB.
2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #18 –
Hi Ted, well after 25 years, that breaker might be faulty, so you could just replace it first. In my experience, a bad breaker wouldn't turn on or stay on at all, even with no power applied.  That it trips immediately, tells me there is a wiring problem somewhere on the way to the automatic bus transfer relay.  Thanks for that picture.  That breaker is rated for 30 Amps continuous duty. It is set to trip at 37.5 Amps.
      Digital Multi-Meters (DMM) are useful tools, and could pinpoint the problem more quickly.  I would check around the vicinty of the transfer relay for loose or disconnected wires. Especially if you recently had the distribution panel out when you replaced the Parallax converter with the PD converter.   RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: Not switching to AC voltage with generator
Reply #19 –
Quote from: RonB  - 

      Digital Multi-Meters (DMM) are useful tools, and could pinpoint the problem more quickly.  I would check around the vicinty of the transfer relay for loose or disconnected wires. Especially if you recently had the distribution panel out when you replaced the Parallax converter with the PD converter.   RonB

I changed the converter out about 8 years ago.

I do have a DMM. Any tips on where to attach it and what settings and readings I should get would be helpful. Electricity isn't my "specialty" 😂

Again, many thanks.

2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #20 –
Hi Ted. One of the black wires removed from the breaker, comes from the generator. With the generator running, see if the meter detects 110VAC on that wire.  With the genset off, (no shore power) see if the resistance of the other black wire to ground is near zero ohms. In this location, ground is essentially the same as neutral. You might read 100 ohms or so for the winding on the relay. A 'dead' short of the order of under 10 ohms would indicate a wiring issue, or a problem with the switching relay. Rats have been very active with all the rain last year in the San Diego area. Look around for wiring damage near the generator.  Hope that it is just a worn out breaker.   RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: Not switching to AC voltage with generator
Reply #21 –
Quote from: RonB  - 
Hi Ted. One of the black wires removed from the breaker, comes from the generator. With the generator running, see if the meter detects 110VAC on that wire.  With the genset off, (no shore power) see if the resistance of the other black wire to ground is near zero ohms. In this location, ground is essentially the same as neutral. You might read 100 ohms or so for the winding on the relay. A 'dead' short of the order of under 10 ohms would indicate a wiring issue, or a problem with the switching relay. Rats have been very active with all the rain last year in the San Diego area. Look around for wiring damage near the generator.  Hope that it is just a worn out breaker.  RonB

I tested the leads.

One produced about 170 volts AC (fluctuating).

The other read .266 on the ohms.
2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #22 –
I assume your reading is to ground, that isn't much resistance. We were looking for a dead short.  If it was mine, I'd put the breaker in and try it. The 170 Volts on the line side is kind of concerning though. I'm not really up on generators, it might need a load to bring the voltage into line. I have dealt with that kind of breaker in the past and they do go bad.

Jon
1994 MB
Re: Not switching to AC voltage with generator
Reply #23 –
Quote from: JonS  - 
I assume your reading is to ground, that isn't much resistance. We were looking for a dead short.  If it was mine, I'd put the breaker in and try it. The 170 Volts on the line side is kind of concerning though. I'm not really up on generators, it might need a load to bring the voltage into line. I have dealt with that kind of breaker in the past and they do go bad.

Jon
Thanks Jon. I have one on order.
2021 Mid Bath
Re: Not switching to AC voltage with generator
Reply #24 –
"The other read .266 on the ohms."

Thanks for posting that screenshot. .266 ohms would be a dead short, or near enough as makes no difference. But reading the "fine print" on your meter's display, it says .266 kilohms, or 266 ohms.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"