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Re: (ET) Running but still odd things, tiny screw head on the thermal breaker, left or right?



The statement about the winding fault being relative to armature position is incorrect. There can be inter-winding faults, as well as a winding-rotor fault. Only way to isolate it is pull the armature and test on a growler. The brushes excite windings that are common from brush-brush and short windings that were once excited to remove stray currents, so they serve a dual-purpose. Due to that nature, it is also possible the commutator just needs undercut. That, too, can cause wierd issues.

Chad

On May 21, 2019 6:22 PM, Chris Zach <cz alembic crystel com> wrote:

Continuing the troubleshooting I took a look at the deck wiring by
removing the wire cover plates. All looked good so I started taking off
the motor wires to isolate the problem.

Sure enough with the center motor disconnected (the oldest one) the
ground fault disappeared. So it's in the motor. I took this one apart to
check and lubricate the bearings and clean out all the accumulated dust
and junk, so it's not that.

Either it's a short in the armature or in the brush housing. I don't
think it is the armature, as a winding short would only ground fault in
certain rotation points and this is faulting everywhere. So I'll pull
off the cap tomorrow and have a look at the two posts. One of them might
have a damaged insulator sleeve....

That and fixing the wire on the main motor with a new lug should fix all
the problems until I can get around to dropping and pulling the drive
motor. Maybe in the fall because I need it now for mowing.

C

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