Generator Runs But No power to Coach

Latitude · 08-29-2009, 09:29 AM

Generator Onan Starts,Run light on,No Fault Codes,Breaker on Onan control Panel not tripped, But no power to Rig

Shore Power works So Transfer Switch is working!!!

Any ideas

Thanks
Rick

Alfa38User · 08-29-2009, 09:48 AM

Quote:

Originally Posted by Latitude

snipped...
Shore Power works So Transfer Switch is working!!!

Any ideas

Thanks
Rick

Are you sure?? The transfer switch (relay contacts) may be frozen/stuck/welded in the shore power position, thus shore power will be connected. Since Shore Power is likely the default position, the relay itself could also be defective.

When the Genny is running, is there power at the switch on the wires coming from the Genny?? Can you hear/feel the relay operate??

The usual problem for these ATS switches is caused by operating them while under load and damaging/burning/welding the contacts. Power transfer should only be done with all loads like A/C, Microwaves etc off.

GaryKD · 08-29-2009, 11:54 AM

Hi Rick,
Double check the transfer switch. Check the outgoing transfer switch power points with a meter, with the generator running.

**Gary RVRoamer** · 08-29-2009, 12:54 PM

Agree with the others - your transfer switch is not transferring. It's stuck in the shore power position or the generator power output is not getting to the switch to cause it to move.

**RV Wizard** · 08-30-2009, 04:42 AM

The transfer switch defaults to shore power. There is no power needed on the contactor coils of the transfer switch to pass the shore power to the coach. When the generator is started, the power from it energizes the contactor coils and the transfer switch now transfers the incoming power from the generator to the coach. You will need to open the transfer switch and with a volt meter measure the incoming generator voltage and the output into the coach. If you have power from the generator and the transfer switch does not put power into the coach (load side of transfer switch) you have a bad transfer switch.

Flagelpater · 08-30-2009, 09:52 AM

Check the Time Delay PCB inside the Transfer Switch box. There is a DIP Switch, On or OFF, change the position. I think ON enables the Time Delay, 20 or 30 seconds. Turn it OFF and see if this makes a difference. Have the GenSet OFF and No Shore Power as you open this Transfer Switch Box. If this is your problem you can operate okay while you get a new CB. Make sure you do not have any load until the GenSet warms up.

skipwil · 08-30-2009, 10:20 AM

Mine was as simple as the breakers had been turned off-(at the generator). I flipped them on and everything worked.
Good luck...

loulong · 08-30-2009, 08:53 PM

Check the breakers on the end of the generator not just the one on the front.
Flip them off and back on.

BZam · 08-30-2009, 09:43 PM

Quote:

Originally Posted by Latitude

Generator Onan Starts,Run light on,No Fault Codes,Breaker on Onan control Panel not tripped, But no power to Rig

Shore Power works So Transfer Switch is working!!!

Any ideas

Thanks
Rick

Not sure when you say breaker on Onan control panel not tripped. Its that out on the generator itself? My Onan Quiet Diesel has a circuit breaker out on the generator.

Flagelpater · 08-31-2009, 09:34 AM

Your problem is Inside the Transfer Switch Box. The Time Delay Circuit Board (CB) has Failed. Move the DIP Switch to OFF. I had the same problem and it fixed it, temporarily. Just because the Shore Power works does not mean the TS is working. Go to the web site of the TS Mfgr. They describe the way the CB works.

Latitude · 08-31-2009, 10:07 AM

Follow Up

The only Breaker I have found is the one on the control panel a 35 Amp 2 Pole AC Breaker which is on and appears to be OK

The Time Delay BiPass I have located But Is this bipass not for the time delay only ???

By turning it to "Off" only eliminates the time delay It does not by pass the TS?? or am I misinformed????

Still Learning

Rick

Flagelpater · 08-31-2009, 10:25 AM

If you turn it OFF the TS will immediately switch to the GenSet. It will not allow the GenSet to power the coach when it fails. Shore Power will pass to the coach okay. The CB is in the upper right corner, 4 wires, held in with a little silicone glue.

phil and terri · 09-01-2009, 09:27 AM

We had the same problem with our generator, replace transfer switch, no luck. Took it to an Onan dealer and they found the voltage regulator was bad. Runs fine now.