Dead Generator

[dnmarkham]

So I just installed a new rooftop ac. After getting everything set up I started the generator to test my work. It was hot in the coach.

Everything worked fine for about 30 minutes and after I stowed my tools, I left the lot to drive the coach home.

When I got to the stop sign I heard the AC's shut down and looked at the gauges. No volts No Amps. Generator was still running.

I shut it down and continued to drive home. When I got home I checked and flipped the breaker in the gennie compartment and then restarted it.

No power, no cooling fan, but no abnormal noises. Smelled of electrical smoke in the compartment.

Everything is working normally on shore power.

I'm guessing I need a new voltage regulator, (I hope I didn't smoke a winding). It was still hot, and I had to get to work, so I didn't open the control box. It's a pain to get into it anyway

Any suggestions for a regulator? go with the Basler? or one of the less expensive knock offs? Any good suggestions for a source?

[Mallie Lennon]

Nathan, I hope the regular is your fix. But if not, a new head it not too bad, I think I have the links if you happen to need one.

[MarkYuma]

The whole with the real Basler. They cost around $500 not the Chinese made version for 50 or $60. I know it’s a big chunk of change but you will be feel a lot more secure if you buy the real one from the factory. I just went through this song and dance a couple of months ago.

[dnmarkham]

Talked to Jeff at powertech today. He had met check voltages across the gennie breaker while it was running. 1 volt across l1 and l3. .4 volts across l1 to common.

According to Jeff, any less than 4 volts indicates dead generator head.

There's only 1504 hours on the hour meter and at least 300 of those are since I bought it.

[MarkYuma]

Well when I got stuck on my generator he was the guy I went to. He can be a little finicky but he will not steer you wrong.
Do you have any signs of a bad bearing or was the generator making any scraping noises when it was running because one of the things that can kill the head is a bad bearing.

You are correct to be looking for a cause of this problem because the hours to seem very low. It would normally take a lot more hours and then to make for a bad bearing as well.

[curtsprenger]

Originally Posted by dnmarkham

Talked to Jeff at powertech today. He had met check voltages across the gennie breaker while it was running. 1 volt across l1 and l3. .4 volts across l1 to common.

According to Jeff, any less than 4 volts indicates dead generator head.

There's only 1504 hours on the hour meter and at least 300 of those are since I bought it.

Low hours is not necessarily a good thing. Low hours usually mean lack of use. Windings get moisture in there and then the problems start.

[Dieselbird01]

Originally Posted by dnmarkham

Talked to Jeff at powertech today. He had met check voltages across the gennie breaker while it was running. 1 volt across l1 and l3. .4 volts across l1 to common.

According to Jeff, any less than 4 volts indicates dead generator head.

There's only 1504 hours on the hour meter and at least 300 of those are since I bought it.

Did you have the Main generator circuit breaker turned off during the test?

Just a guess but if the circuit breaker and fan switch were "on", it seems like that would influence the measurements across L1 & L3.

[dnmarkham]

Mark,

I'm not sure if it was making a "scraping" sound, but I did think it's been running a little loud lately.

It has always struggled under heavy load, anything over 30 amps per side and the voltages would drop.

Jeff seems to know his stuff, I'm considering taking the coach to him for the repair.

Curt,
I agree low hours is bad, I make a point to run my generator under load regularly, and I don't hesitate to run it on the road, especially in the summer.

John,
The breaker and the fan were on, Jeff didn't tell me to try it any other way. I called him initially to ask how to diagnose the AVR, and he told me before he could do anything to start it and measure the voltage. When I reported the voltages, he said there's nothing we can do, the windings are toast if less than 4 volts showing.

He suggested that the rear bearing may have failed, or the diode plate may have cracked, but said a sudden failure under load is how they usually go.
The AVR is one of the old style (completely sealed) and it looks completely normal, not overheated or cooked.

The generator compartment smells of burnt electrical insulation, so I'm not too surprised with the diagnosis.