Testing a Genny

[Farm130]

When testing the voltage being produced by the genny must the field terminal be grounded as well as the case while using a voltmeter on the Alt terminal?

 

[John T]

The case obviously has to be grounded cuz the armatures voltage is across the ARM terminal and the grounded brush. It will still produce voltage with an ungrounded field (provided the presence of residual magentism in the field poles) but less then if it were case grounded (field current produces electromagnetism). However, the open unloaded output voltage of a genny dont really tell ya all that much, its what it can produce when coupled up to a load and how much it can raise battery voltage when atatched to it that counts.....

If you need my charging troubleshooting procedure which includes a genny motor test and how to tell if non chargign is a genny or a voltage regulator problem, search the archives or let me know

best wishes

John T

john T

 

[hbauer]

John, Could you send me that non charging
genny checklist please? I suspect the voltage regulator. I scored the mica between commutator bars but it did not help. I advanced the third brush 3 bars from static brush..did not help either.

Could use some help. Thanks.