Small portable generator repair

[Legacysteve]

I'm not overly familiar with small generator repair. It's a 5000 watt off the shelf generator, and it worked good until recently when it quit in the middle of running. Engine starts and runs good, but no voltage is produced. Measured for resistance across the 2 ac leads, and never got any resistance. After opening her up I found this.

It looks like that insulated wire should go somewhere....

 

[slow]

Can't see the picture, can you repost it?

 

[Legacysteve]

Can't see the picture, can you repost it?

Sorry I just reposted the link. Just add https to it.

 

[Bighead38]

I see it but don’t know what they are supposed to look like inside.

 

[Legacysteve]

Yeah thats my problem also.. I haven't done a lot of work on them outside of the engine... It looks to me like that wire blew off of somewhere, but I can't find any stray connections...

 

[theoldwizard1]

Generators (which technically are alternators because they make AC current, but then again we call car "generators" alternators when the output DC power ! Are you confused yet ?) are really simple. The part that spins an electromagnet call the field and it get power through brushes that ride on those 2 rings. You should be able to measure some resistance there.

The windings that are stationary are called the stator. Assuming it is a US 240V generator it is made of one continuous piece of wire with a "tap" in the middle (neutral).

Are you sure those are wires ? They look like some kind of cord used to wrap the insulation and keep it in place. Cut back the insulation around that spot on the left and see if any wires are chafed through underneath.

You should be able to read resistance between the 2 hot and either hot or neutral. If not there is an open somewhere.

 

[TractorJeff]

To one of those copper rings.
That would make the magnetic field to produce AC in the stator winding.
Engine must run at 3600 rpm as there are only poles on that armature.
The AC is produced in the outer stationary ring (stator).
I would assume that there should be a measurable resistance, even if it is only an Ohm or two.

 

[Bretny]

The unit is in front of you and not us. We cant see whats behind that bundle of wires but i would suggest starting by looking around in there.

I had one box store generator with 4hrs..the rectifier wireing was rubbing on the stator. All could have been fixed with a zip tie from the factory. These things dont have the best quality control.

 

[log man]

In the upper and lower left of the picture, several of the copper windings have been impacted by something and would need to be addressed and re-vanished too to prevent shorting, assuming you can address the white wire issue.

 

[nsula_country]

My experience with modern generators is the Automatic Voltage Regulator (AVR). I have seen some with a capacitor and some with a diode board with capacitors. When the AVR fails, 0V output... Find where the AVR is. If cap check it. If a board, find one and replace, I have replaced them before under $50.

Another thing that really stresses the AVR on generators. Starting and stopping the genset while under load (loads plugged in) is bad practice. ALWAYS start unit before plugging in, ALWAYS unplug before shutting down and try not to run out of fuel while under a load.

CT

 

[Dingleburry]

But car alternators output ac...?

Generators (which technically are alternators because they make AC current, but then again we call car "generators" alternators when the output DC power ! Are you confused yet ?) are really simple. The part that spins an electromagnet call the field and it get power through brushes that ride on those 2 rings. You should be able to measure some resistance there.

The windings that are stationary are called the stator. Assuming it is a US 240V generator it is made of one continuous piece of wire with a "tap" in the middle (neutral).

Are you sure those are wires ? They look like some kind of cord used to wrap the insulation and keep it in place. Cut back the insulation around that spot on the left and see if any wires are chafed through underneath.

You should be able to read resistance between the 2 hot and either hot or neutral. If not there is an open somewhere.

 

[nsula_country]

But car alternators output ac...?

I believe they are 3 phase AC rectified to DC.

Dingleburry, is your avatar a picture of a Troy Bilt rear tine tiller, tine shaft and drive gear? It looks VERY familiar to what I found when I rebuilt a 1978 Troy Bilt Horse...

CT