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(ET) More lift motor observations
Got another pair of broken lift motors here at the house. Sat down and
took them apart for a look-see.
The first one was... well, cremated is a good way to describe it. One of
the brush wires had burned through, but before that happened the wire
from the field coils to the bottom brush incinerated *all* of it's
The circuit breaker likewise was toast. Think "destroyed" here. As in
burned away to nothing. The wire going to the back of the motor (the
common return wire) was also burned out to the point of being a crumbly
burned up mess.
Apparently this motor had a "hard" life.
The second one was in better shape, however it wasn't going to work.
Apparently the brushes were "replaced" and the new ones are so long the
springs can't keep them against the commutator. That would explain a lot.
I think this one had a more "gentle" life.
Summary: These motors are burning up due to overload. I'm not sure if
running them at 12 volts is a better idea, or if they just need to be
treated a bit better. They also have no grease in them, have high
friction, and are filthy as hell. Maybe running them at 18 volts just
causes the current to jump too high, and the wires can't take the extra
watts being dropped. Maybe the interconnect wires are old, and as a
result they increase in resistance and cause problems. Maybe 12 or 10
gauge wire will hold better than the 14 gauge stuff in there now.
I'll work on them over the next few weeks.