Generator Issue

[strudeau]

Helping a buddy work on his Coach. Thought he was having a problem with his Transfer Switch because he has power when hooked up to 50 amp Shore, but when dry camping the genny will provide power sometimes and then nothing. All breakers are good, both on the genny and in the coach.

Tested the power to the transfer switch and it's good, so assumed that the switch just wasn't flipping over to provide power to the service panel. Replaced the Transfer Switch and the problem didn't go away. Still have genny power at the switch, but nothing into the Coach.

What are we missing here?

[garry1p]

I also suspect your new switch is bad.

The delay circuit provides 120V"DC" to the relay coils so you may have a bad delay circuit or a bad rectifier if so you will not pull in the contacts.

[strudeau]

dougrainer wrote:
What is the actual voltage from the Genset? Do NOT say 120, state the actual digital read out voltage. Doug

Sorry about the delay but as I said this is my buddies Coach so I didn't have immediate access.

Tested the L4 and L6 wires coming in from the generator. Both are reading 122-123 so it's within range. When I tested the T-4 and T-6 leads coming out of the contractor, I get 122-123 on the T-4 leg and zero on the T-6 leg. I'm guessing this new switch is bad?

[big_jim_2]

Try tightening all the connections on your converter with a screwdriver. Careful, shut off all power from shore, generator and inverter first. That worked for me I found one screw was slightly loose.

[crasster]

Yeah, I would say voltage regulator as well. Post some read outs.

[dougrainer]

What is the actual voltage from the Genset? Do NOT say 120, state the actual digital read out voltage. Doug

[enblethen]

I would suggest putting a load directly onto the genset side of the transfer switch.
It should be about 1200 watts. This would do a light load test on the genset itself.
You could try resetting the circuit breakers on the genset.
Have you checked the control fuses on the genset?

[mfox20]

Yes, the voltage regulator on mounted on the generator.

[GNR]

Yours should have shore power connected through and when the generator feeds power to the transfer switch, a time delay of about 30 seconds allows the generator time to warm up and then the contactor coil is energized and power is then provided from generator through the transfer switch and into the coach.
If it is a Newer coach a Surge Guard may be built into your EMS system and this is normal operation. It may also be why the power dropped out after 20 minutes. If the voltage gets too low or too high, or even a surge can cause the Surge Guard to do it job and protect your coach by disconnecting power.
When the power has been interrupted, and if you are comfortable in checking inside the transfer switch with a volt meter to determine if power is getting through the Surge Guard and if so getting through the transfer switch. These terminals will be marked on the inside of the transfer switch . Remember to use the Neutral from the generator for all Volt Meter readings

[strudeau]

mfox20 wrote:
Could be the voltage regulator. Had same symptoms on a Onan 5000 a couple of years ago and that was the fix.

If you post the brand, size/model number you will get a lot of good troubleshooting tips.

Onan 8KW. Are you referring to the voltage regulator on the genset itself?

[strudeau]

enblethen wrote:
When you checked for incoming power to the transfer switch from the genset, did you read two legs of 120 volts to the neutral from the genset?
Did you check for two legs of 120 volts leaving the transfer switch going to the 120 volt distribution panel?
What is make and model of genset. Is it 120/240 or two legs of 120?
Does the rig have an energy management system?

Generator is a Onan 8KW.

It's two legs of 120. Tested both legs coming in from genset and it's good. Nothing coming out to panel. This was happening both with the old, and now new transfer switch.

Coach does have a energy management system and it shows no power to the coach unless it's hooked up to shore power.

Weird thing is that after not working on the genset, he will drive the coach, park, and fire the genset and it will work for a period of time and then quit producing power. Again, all breakers are good and haven't tripped.

[enblethen]

When you checked for incoming power to the transfer switch from the genset, did you read two legs of 120 volts to the neutral from the genset?
Did you check for two legs of 120 volts leaving the transfer switch going to the 120 volt distribution panel?
What is make and model of genset. Is it 120/240 or two legs of 120?
Does the rig have an energy management system?

[mfox20]

Could be the voltage regulator. Had same symptoms on a Onan 5000 a couple of years ago and that was the fix.

If you post the brand, size/model number you will get a lot of good troubleshooting tips.