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Topic: Generator cooling fan motor fouling (Read 925 times) previous topic - next topic

Generator cooling fan motor fouling

Seven years ago I had a Sheppard steering box seal failure as many of you have experienced.  I had it replaced with a Sheppard reman unit and cleaned up the basement bay next to the steering box, the side of the coach, and the toad.  Last week I experienced generator shutdown on overheating.  This was traced to the generator cooling fan motor.  FT Parts promptly sent me an exact replacement, as well as the motor capacitor(which they recommended).  When I removed the old motor, the bearings seemed fine.  I didn't notice any electrical burns or smell.  But I did find the motor absolutely filled with oily dirt plugging all the motor cooling slots.  I think that the motor sucked in oil mist until I cleaned the compartment, which then promoted the dirt build up. 

I can't yet guarantee my diagnosis, but I mention it because the corrective action is so easy.  The motor is covered by a sheet metal cover attached to the cooling fan housing with a half dozen sheet metal screws.  Once removed, the motor is very accessible.  You can't remove it without removing the whole fan assembly, but you can clean it.  The new motor instructions call for vacuuming dirt from cooling slots and blowing out with air.  They caution about using solvents, but I think you could safely wipe down the outside with a rag and cleaning fluids before blowing out the motor.

I suggest everyone that has experienced a steering box seal failure check the cleanliness of their generator cooling fan motor.

Re: Generator cooling fan motor fouling

Reply #1 –
Brett, cleaning after raising dirt is always a good idea. BUT, not to steal your post, but I am, I pulled our generator in our '89 GV.
After removing the engine shrouds I found a lot of black "stuff" melted onto the engine fins. I think it was the plastic tape FOT edged the insulation with.
  When I touched the original black foam insulation it just crumbled into powder. I used my shop vac to remove the loose stuff and then scraped down to bare metal. New sound insulation fire proof barrier going on next week when it arrives.
If anyone still has the old black foam insulation, check it by touching it. If it crumbles--get busy!! If you find loose shiny black plastic hanging anywhere you will probably find some melted on the engine fins.

Re: Generator cooling fan motor fouling

Reply #2 –
You also should look at the generator radiator. Mine was full of that old insulation.

Re: Generator cooling fan motor fouling

Reply #3 –
They do make spray and imersion type cleaners for electric motors.

Re: Generator cooling fan motor fouling

Reply #4 –
Yes, I cleaned the radiator as well-I should have mentioned that.  The water ran black for quite a while.

Re: Generator cooling fan motor fouling

Reply #5 –
Sorry, John. Ain't got no radiator on our generator!! Air cooled two cylinder propane fueled Onan Emerald III.
Very low tech. Still works after 28 years and 348 hours on the meter.

Re: Generator cooling fan motor fouling

Reply #6 –
Only 348 hours after 28 years?  I hope you're running it once a month under load to keep it in good shape. 

Re: Generator cooling fan motor fouling

Reply #7 –
Maybe twice a year. Don't want to overdo it! >:D
I know what people say, but we are not in the high moisture environment like you folks down south. Most of the time the humidity is so low that if you spit it almost never reaches the ground.
The generator has started and ran perfectly every time I start it up. Only reason I took it out was to clean out the mouse housekeeping mess and try to determine why the start feature on the control panel and in the bedroom don't work.
Now I am replacing the powdery O.E.M. insulation--using today's technology plus the old mechanical standby--fender washers and pop rivets to supplement the spray adhesive. ^.^d

Re: Generator cooling fan motor fouling

Reply #8 –
Well, generator was out, OEM compartment insulation out (YUK!!) new insulation in, and now slid generator back in after tuneup, cleaning, new plugs, air cleaner, and greasing the angle slide rails. Took a whole 20-30 seconds to get the generator back in place including sliding it off the cart. Perfect height--and mobile.

Re: Generator cooling fan motor fouling

Reply #9 –
Color me green with envy. That baby looks fine!
jor
 

Re: Generator cooling fan motor fouling

Reply #10 –
Well, got the generator in. Had to wait for exhaust elbow, as the old one was cracked. They are cast iron by the way. Wired it up, took a deep, deep breath--had the DW standing by the generator and watching for smoke, took another deep, deep breath, and started it up and let it run.
YAHOO!!! Fired right up, Powerwatch gauge  popped on and read 115 volts. Life is good!! OH OH!! All kinds of cotton fuzz flying out by the cooling fan and between the shrouds and the engine cooling fins!! Guess I didn't get it all when I had the shrouds off. We collected and pulled about a hardball size ball of cotton. I had previously taken that much out when I had the generator out and the shrouds off.
Compartment & generator now look as good as the drive engine compartment and now no black crumbling powder getting all over everything.

Next week? New slide bars for the Zip Dee patio awning on the coach!