generator problem(s)

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember NoSpam saying something like:

The most common cause of this on a genset that's been lying unused for ages is damp in the windings. Take off the end cover and direct a 1kW fan heater into the end of the alternator for a few hours then try it.

Not too close with the heater, mind.

[Sylvain VAN DER WALDE]

How can damp affect _insulated_ windings?

Sylvain.

[Ed Sirett]

It most certainly can. Presumably the insulation is not very thick and can contain microscopic fracture which allow the ingress of moisture and/or dirt so great increasing leakage current and lowering breakdown voltage.

Armature winders would not otherwise go to great lengths to bake winding dry before and after dipping in the varnish vat.

[Mark]

I have dug out and scanned a test page from a manufacture, how much this applies to your generator only you can decide.

finial thought, you have checked for voltage on the hot side of the circuit breaker.

-

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Sylvain VAN DER WALDE" saying something like:

They're only insulated with pixie snot.

[Sylvain VAN DER WALDE]

Thanks for that info.

Sylvain.

[NoSpam]

Thanks Mark. I just did some poking around and it turned out to be a much simpler beast than I was expecting. 2 output windings (which are series/parallel switched for 240/110) and an excitation winding with a capacitor across it. All the windings were OK but the cap was short circuit - replaced it and all now works. Thanks for various suggestions and information.

Hugh

[Mark]

Well done, This would probably a close match to your wiring schematic then.

[NoSpam]

Sort of. There are two 110 windings which are series/parallel switched and there's no DC output. But the excitation and armature are the same.

Hugh