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excessive arcing on central vacuum motor brushes?
QUESTION: I had to replace the brushes on the Vacu-maid central vacuum lately (it has
a Lamb motor). When it runs, it arcs way too much, running until the safety
relay cuts out to turn it off (it is also pretty hot at this point).
Any ideas what is wrong? I used a special type of stone to clean off the
copper commutator that comes in contact with the brushes (I realize that
there should be some sparking, but this sparks way too much). Maybe the
commutator is too worn to make an even contact with the new brushes?
Anyone have any ideas?
ANSWER: Or maybe the brushes where not fitted to the commutator? did you take
some sand paper and turn it back ways on the commutator and then leave
the brushes in place and then turn the commutator back and forth with
the sandpaper to wear the brushes down to the correct arc? so they
will fit the commutator?
worth a try.
Sounds like you better think about a major overhaul here. At the least the
commutator should be machined smooth and the motor windings checked for shorts
and /or grounds. Stop gap measures could easily kill the motor. If it's already
on the way out you'll not waste time trying to revive a corpse. Check
replacement motor costs vs. service and repair costs and then decide. Good
luck.
Besides what the others said about matching the brushes to the
commutator, when ever I have a motor apart, I clean the commutator
carefully. Taking a very fine dental tool, I scrape out any crud
between the copper plates. Make sure you get all the way down to the
bottom insulator. Then I use a fiberglass brush
http://www.eraser.com/catalog.cgi?mode=details&product_id=1222 or a
http://www.eraser.com/catalog.cgi?mode=details&product_id=1225
to clean the tops of the copper, then once again, scrape out the crud
between the plates.
By the way, those are two tools that are indispensable in both my tool
box and in the shop. They clean electrical and electronic connections
better than anything else I have ever used. Be careful though, or you
will most likely get fiberglass splinters in your fingers. I am in no
way affiliated that company, I simply love those two tools.
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