Generator overheat isssues

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Generator overheat isssues

August 31, 2019, 08:19:50 am

So story goes, after fuel line changes didn't worry about the generator, but when I finally tried to start, woudn't start. Fixed that, just poor prime.
But she would run for a little while then cut out. High temp alarm. Found coolant low. Fixed that.
Still having issues with high temp.
My Isuzu powertech 10K generator has a remote radiator and a squirrel cage fan under the drivers seat. Not sure if they are all like that.
The fan is not coming on. There is no 120 volt power coming off the generator. I have a manual transfer switch.
I ran a continuity tester to both poles of the circuit breaker and got tone. With or without the breaker tripped. That is strange I thought. The Generator electrical box has been modified in the past and part is remotely mounted next to the squirrel cage fan. Make it difficult to see the fault lights.
I have ordered a new thermostat, new water pump. Changed to air filter. Will do a oil change next week with new fuel filters. Fuel already goes thru a Racor 500 I installed when I switched the fuel lines out.
I am thinking its a electrical issue. What do the experts or more experienced people here think? Hate to take it in at this point to have someone do it if I can fix it myself.

Thanks!
Bob

Re: Generator overheat isssues

Reply #1 – August 31, 2019, 08:27:26 am

Already did a search on the forums and didn't find the answer to my issue.
What is the best way to check if the generator head is putting out power? I planned on running a tester on the breaker but it's so damn hot out here right now, got dehydrated and figured I would check tomorrow.
There are 3 breakers on the front panel for the electrical box on the genset, 1 45 amp breaker, 1 cooling fan switch breaker, and 1 generator breaker. Do they all have those 3 or is this a mod of this unit?
Thanks
Bob

Re: Generator overheat isssues

Reply #2 – August 31, 2019, 08:53:35 am

Bob, With all breakers at the gen engaged, start the gen. If the radiator fan is running, gen is making power. If no fan operation, no gen power, no cooling so please shut gen down.

If any electrical outlets in the coach show 120 vac with a vom meter, the gen is making power that is passing through the electrical breaker box under the bed.

Hope this helps

Re: Generator overheat isssues

Reply #3 – August 31, 2019, 09:31:25 am

As Rudy said above, check to see if fan is turning. If not check the start capacitor on the fan motor. I was having problems with over heating and it was the start capacitor.

Re: Generator overheat isssues

Reply #4 – August 31, 2019, 11:47:11 am

Thanks guys.
No 120V power in coach via genny
Fan is not turning. I will pull the motor and check the start capacitor.
But shouldn't there be power to the coach still.. before the overheat shuts it down?
Unless the breakers are bad.
Don't have time today to check it. Work the next 3 days and 4 12 hour shifts this week. But next week will have plenty of time to troubleshoot it.
Hopefully the AC units will be in by then too.

Re: Generator overheat isssues

Reply #5 – August 31, 2019, 12:16:24 pm

Try calling the Powertech tech,he has been helpful in the past.

Re: Generator overheat isssues

Reply #6 – August 31, 2019, 12:24:48 pm

You will have power in the coach until the generator overheats and shuts down. Doesn't seem like a bad fan. To trouble shoot check the voltage at the 45 amp breaker if you have 4 or more volts bad regulator. Also check the 45 amp breaker for continuity with power off.

Re: Generator overheat isssues

Reply #7 – August 31, 2019, 12:37:00 pm

Quote from: Bob and Julie – August 31, 2019, 11:47:11 am

Thanks guys.
No 120V power in coach via genny
Fan is not turning. I will pull the motor and check the start capacitor.
But shouldn't there be power to the coach still.. before the overheat shuts it down?
Unless the breakers are bad.
Don't have time today to check it. Work the next 3 days and 4 12 hour shifts this week. But next week will have plenty of time to troubleshoot it.
Hopefully the AC units will be in by then too.

If you don't have power to coach, then probably not the fan capacitor. On mine the generator would run for a while(10 minutes or so), make electricity, and then shut down.

The capacitor is right on front of fan. Just open door and there it is.

Re: Generator overheat isssues

Reply #8 – August 31, 2019, 01:05:29 pm

Quote from: craneman – August 31, 2019, 12:24:48 pm

You will have power in the coach until the generator overheats and shuts down. Doesn't seem like a bad fan. To trouble shoot check the voltage at the 45 amp breaker if you have 4 or more volts bad regulator. Also check the 45 amp breaker for continuity with power off.

checked it, it had a tone with both on and off. With it off should have no tone, correct?
Other place I can check is the power out in front of the genset to give power out like to run a house. I will try it there next. I think that with the fan running the the overheat issue will go away.

Re: Generator overheat isssues

Reply #9 – August 31, 2019, 01:17:15 pm

you would have to take one of the wires off the breaker to continuity check

Re: Generator overheat isssues

Reply #10 – August 31, 2019, 01:18:26 pm

I replaced the 2 45amp main breakers and the fan pop out breaker a while ago. Fixed that issue. They felt "good" tough life on them

Re: Generator overheat isssues

Reply #11 – August 31, 2019, 07:15:06 pm

When mine had a bad rotor winding, the generator would start and run for a short time, then shut down due to overheating due to radiator fan not running due to no ac power from the generator. First thing checked was the voltage regulator, no luck, needed rotor rewound.

Re: Generator overheat isssues

Reply #12 – August 31, 2019, 07:33:04 pm

Tom where in la did you take your coach to for the gen issue?

Re: Generator overheat isssues

Reply #13 – September 01, 2019, 01:43:40 am

Here's where I took it.

Wrights Supply, Inc | Sell and Repair Electric Motors

I used the power tech website to find them, that was ten+ years ago.

Service Dealer Map - Power Tech Mobile Generators

Re: Generator overheat isssues

Reply #14 – September 01, 2019, 11:04:43 am

Thanks. You took the coach to the Glendale location?

Re: Generator overheat isssues

Reply #15 – September 01, 2019, 11:14:32 pm

Yes, Glendale.

Re: Generator overheat isssues

Reply #16 – September 02, 2019, 01:23:47 am

Quote from: Tom Lang – August 31, 2019, 07:15:06 pm

When mine had a bad rotor winding, the generator would start and run for a short time, then shut down due to overheating due to radiator fan not running due to no ac power from the generator. First thing checked was the voltage regulator, no luck, needed rotor rewound.

Ouch. How many coach bucks would that set me back?

Re: Generator overheat isssues

Reply #17 – September 02, 2019, 12:07:53 pm

Bob I sent you a PM

Re: Generator overheat isssues

Reply #18 – September 02, 2019, 01:13:30 pm

Quote from: Bob and Julie – September 02, 2019, 01:23:47 am

Ouch. How many coach bucks would that set me back?

.

That was ten years ago. Good Sam extended service paid about $2000 for the repair. Mostly after lost of attempted refusals to pay. I canceled the service plan after that, it wasn't worth the anguish.

Re: Generator overheat isssues

Reply #19 – September 03, 2019, 01:08:27 pm

OK all fixed. Found the issue. The white wire coming off the generator push breaker that goes to the #3 on the regulator was broken off. A quick change out with a new connector and all is well. Probably should rewire the entire thing pretty soon. Looks beat up in there. Big squirrel cage fan comes on now. Ran the generator about 30 min with good voltage and no temp issues. The hoses read less than 140 deg F on the laser thermometer.

Appreciate all of you how took the time to help out. Hope this helps someone else down the road.
Next I will change the oil and filter and fuel filter. Waiting on a few replacement parts for the future. Might pull the genny out and put some sound insulation in too.
Bob

Re: Generator overheat isssues

Reply #20 – September 03, 2019, 08:12:01 pm

Bob,

Glad you solved the problem. Shortly after buying my coach twelve years ago I had a number of generator problems, all related to the significant vibration of the electrical box on the top of the generator. The squirrel cage fan circuit breaker gave out and tripped easily and I had several wires to the control board shaken loose or broken as well as two circuit boards themselves go bad.

So, I extended all the wires and relocated all the guts of the electrical box that is mounted on the top of the generator to the forward port side bay. The only thing left in that box is the double 45amp primary circuit breakers for the generator. The auto-start box had been moved by FOT when the original owner had the coach. Below are photos of my set-up. It does make access to the various components a bit of a PITA but I have had no generator electrical problems in the eight or ten years since I made the change. I added the listing of the fault light codes to the face of the Auto-start box since the original listing, on the side, is impossible to read.

Richard

Re: Generator overheat isssues

Reply #21 – September 03, 2019, 08:48:31 pm

Richard,
Do you have a Kabota or Isuzu? Curious if the Isuzu has more vibration.

Re: Generator overheat isssues

Reply #22 – September 03, 2019, 09:08:43 pm

Quote from: craneman – September 03, 2019, 08:48:31 pm

Richard,
Do you have a Kabota or Isuzu? Curious if the Isuzu has more vibration.

Isuzu. Has a lot of vibration on startup but settles down when running. Might need to replace the mounts.

Re: Generator overheat isssues

Reply #23 – September 03, 2019, 09:10:19 pm

Quote from: Jan & Richard – September 03, 2019, 08:12:01 pm

Bob,

Glad you solved the problem. Shortly after buying my coach twelve years ago I had a number of generator problems, all related to the significant vibration of the electrical box on the top of the generator. The squirrel cage fan circuit breaker gave out and tripped easily and I had several wires to the control board shaken loose or broken as well as two circuit boards themselves go bad.

So, I extended all the wires and relocated all the guts of the electrical box that is mounted on the top of the generator to the forward port side bay. The only thing left in that box is the double 45amp primary circuit breakers for the generator. The auto-start box had been moved by FOT when the original owner had the coach. Below are photos of my set-up. It does make access to the various components a bit of a PITA but I have had no generator electrical problems in the eight or ten years since I made the change. I added the listing of the fault light codes to the face of the Auto-start box since the original listing, on the side, is impossible to read.

Richard

Richard have somewhat the same setup but the breaker for the fan is not remote mounted. Makes it hard to see the fault lights there but if it cuts down on issues that is fine with me.

Re: Generator overheat isssues

Reply #24 – September 05, 2019, 08:15:22 pm

Richard,
I expect you found in your investigation that your start capacitor is on the back side of the fan motor. You can only see it by sliding under the front compartment and looking up.

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