Generator voltage drop.

[gsf35099]

Hi gang,
I've got a Guardian QDP75 generator that is dropping volts and squealing when a heavy load is on. Pretty sure it's the drive belt slipping & I have a new one for replacement.

Has anyone had a problem with the barring going out on the tensioner? Wondering if I should get a replacement for that as well or just try the belt first.

I found a post on another site where someone had the exact same problem & said spraying belt spray on it made the problem go away. Assuming that was only temporary.

Thanks for any advice.

[gsf35099]

Figured I would come back with update.

Replaced tensioner, pulley, and drive belt. Loaded generator down with both AC's & a compressor and voltage never dropped below 115v. :B
Tensioner, pulley, and belt were all about shot!!

Thanks again for the feedback. Can't say enough about the people out here willing to provide advice. This DIY saved me a $ Grand easy. Having a shop unbolt and move the generator around to be able to get to things would have cost me a fortune. With a buddy's help, took us <1 1/2 hours and that included the clean up.

[gsf35099]

bounder39zman wrote:
you are probably correct in your diagnosis, and you are right....belt spray may take the squeel out, but not the slippage (for very long).
The tensioner pulley usually needs replaced when belt is replaced. It may seem ok for now, if the pulley spins freely and belt surface not worn, but will it last the whole life of the new belt? It is not that expensive of an item, and a good idea to replace while you are doing job. If other belt has not been replaced, would be a good idea (P.M.wise) to change it also. If voltage output is ok under light to medium loads, then your generator components, ie rotor, stator, voltage regulator are probably good

Thanks. I was thinking it would be good idea to replace the tensioner as well. Just to be safe.
The other belt was replaced last year & I have two spares. :-). I also had the voltage regulator replaced a couple years ago because it was all over the place. I'm betting it's the belt & pulley as I have a consistent 115v with light to medium loads.

Thanks again.

[mci7]

Yes Generjunk did produce belt driven 3600 rm generators, most have realized the folly on the overall short longevity cheap non econimical ads that Generac has.
Dave M

[bounder39zman]

you are probably correct in your diagnosis, and you are right....belt spray may take the squeel out, but not the slippage (for very long).
The tensioner pulley usually needs replaced when belt is replaced. It may seem ok for now, if the pulley spins freely and belt surface not worn, but will it last the whole life of the new belt? It is not that expensive of an item, and a good idea to replace while you are doing job. If other belt has not been replaced, would be a good idea (P.M.wise) to change it also. If voltage output is ok under light to medium loads, then your generator components, ie rotor, stator, voltage regulator are probably good

[jolooote]

It could also be that the Generator? or Alternator? has an abnormally high current load on it. This causes very high torque on its armature an makes it very hard to spin which could result in the belt slipping/squeeling.

[gsf35099]

Well, the style I have has a belt for the drive on one side and water pump belt on the other. Plus seeing a similar problem someone else had 3 years ago gives me confidence it's the problem. Just wasn't sure if I have a bad bearing as well since the gene only squeals under a heavy load.

[bshpilot]

most generators are direct drive at least to between the engine & motor (gen head).

unless its the belt for the fan or alternator ? I wouldn't think those would impact the voltage output much though.