Onan 8.0 High Voltage Problem

[K Sarich]

Hello,

Started up Generator and noticed the voltmeter inside was reading in the red, measured volts at an outlet and read 135v. Shut generator down, read manual, and it mentions being able to adjust voltage at the transformer using "tabs". Doesn't say how too though.
Is this something this the right way to adjust and is it something an average person(me) should attempt.
The generator runs great, but has sat for probably a year or so without being under load.

As always looking for suggestions.

Thanks
Kevin

Kevin,

Here's a thread where a condition similar to yours was caused by a shorted rotor, although it wasn't diagnosed on an Onan generator. Good reading nonetheless:

http://www.wanderlodgeownersgroup.co...?t=7554&page=2

[K Sarich]

Thanks for the link David,

Going to give Onan a call and see what their guess is and will report back. Hoping for something that doesn't require removing the genny, although it was one item that the previous owner said was in unknown condition.

Kevin

[Bill Pape]

.
There are two 110v meters , were they both at 135 volts ???
was the transfer switch in the generator position ??
what is the meter readings on shore power??


If the cooling fan under the rear bus is running it may be at the proper voltage, the fan needs 220 , which indicates both legs have power.

To not power up the main AC panel , you may want to check for proper voltage, at the generator circuit breaker panel located in the next bay or under the bed. careful with the meter, when checking 220 volts, it is present on the terminals.

[gcyeaw]

Kevin,
I know a few folks that have had problems with their later model FC generator due to the sound proofing material flaking off over the years and blocking the cooling. If not addressed it can result in major engine damage and a BIG repair bill on the Onan. I do not know the specifics of the Onan but if the voltage is really at 135, something is wrong. Normally once set the voltage level shouldn't vary very much. Better to diagnose and fix it now than to try to adjust it and have a failure in the middle of a trip.

You are right to check with Onan, but thay are likley to refer you to a service facility. Maybe someone on the forum can reccomend someone near you.

[jnxmas]

Check engine speed.

[K Sarich]

Thanks for all the replies guys, they were spot on.

Spoke to an Onan repair guy and he mentioned it could simply be engine speed. Went back fired genny up and after a brief warm up put legs under a load.
Leg 1 with water heater on was 123v.
Leg 2 with small space heater on was122v.

Removed loads and each leg jumped a volt or two. Not perfect but way better. Ran the genny for about 20 minutes and voltage seemed to drop the longer it ran.

I'll read up on the throttle and adjust it tomorrrow. Hopefully that will work.

What is the best or maybe I should say easiest way to get rid of any insulation that may be blocking the radiator? Compressed air? Vaccuum?

Thanks
Kevin

[Bill Pape]

difficult to clean the radiator & fan without removal, it is under the bus. try spray soap & hose water.
There is also a small squirrel fan behind the reservoir & battery, it is probably blocked. Suck some of the loose insulation with a shop vac out of the generator bay.

[iamflagman]

Originally Posted by K Sarich

Thanks for all the replies guys, they were spot on.

Spoke to an Onan repair guy and he mentioned it could simply be engine speed. Went back fired genny up and after a brief warm up put legs under a load.
Leg 1 with water heater on was 123v.
Leg 2 with small space heater on was122v.

Removed loads and each leg jumped a volt or two. Not perfect but way better. Ran the genny for about 20 minutes and voltage seemed to drop the longer it ran.

I'll read up on the throttle and adjust it tomorrrow. Hopefully that will work.

What is the best or maybe I should say easiest way to get rid of any insulation that may be blocking the radiator? Compressed air? Vaccuum?

Thanks
Kevin

Kevin,

How dirty is the throttle linkage joints? It could be that just after the engine warms up the greasy joints loosen up a little and thus the engine speed settles down, cleaning them up and then some fresh lubricant on the throttle linkage might resolve the issue.

I know my body joints work better once I warm up...................even after I remove all of the dirt and grease

[Turbokitty]

A Kill-A-Watt meter is great because it will tell cycles (Hz) as well. There are around $40.00 and are a quick glance to see what is happn'n