any electrical motor folks?

[idosubaru]

I drilled through a few, like maybe 5, copper windings in an electric motor. Small exhaust fan motor. Part of me thinks with all of those thousands of winds, losing a few isn't that big of a deal.

 

$150 for a new motor so I'd rather just install the $4 bearing and call it a day. It takes 5 minutes to install or remove so not much to worry about.

[nipper]

Well you may have opened up a circuit, or shorted out a few poles.

 

You may ant to take it apart and take a meter to it and see what damage you have done.

[presslab]

An exhaust fan like in a residential application? That would likely be an induction motor, with no brushes.

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/indmot.html

 

Cutting any of the windings will cause the motor to work very badly, as the consecutive winds are in series, and cutting just one turn will cause the current to stop flowing.

 

If a few turns are shorted out it's not a big deal. So maybe you can take a soldering iron to the cut windings and solder them all together. A soldering iron will eventually melt the varnish on the wires if you keep it there for a bit, and then you can blob solder on it. This is all assuming that the windings you cut are adjacent, and that's hard to say.

[Fairtax4me]

Like press said, each winding (wire) is basically a circuit all it's own. The copper winding is coated with an insulator so the electricity flows all the way through the length of the wire rather than jumping straight across to the closest exit point.

If its a brushed motor the open or shorted windings will create a dead phase. You'll get no "push" no magnetism from that winding. As the motor turns around you basically end up with the equivalent of a misfire to a gas engine. It causes the rest of the motor to work harder and creates more heat. There's also the possibility of the broken strands breaking loose and shorting against the case while the motor is turning. Do you like fireworks?

 

I'd see if there is a motor place nearby that can rewind it or source a new armature.

 

If its an induction motor (3 phase?) I'd just solder the broken ones together.

The affect depends on the number of turns and just how any windings are in each coil. Probably wont notice too much difference but it would be wise to monitor the temperature of the motor and the "repaired" coil for a while just to make sure it isn't going to overheat. (Could catch fire or burn out the solder)

[idosubaru]

The copper winding is coated with an insulator so the electricity flows all the way through the length of the wire rather than jumping straight across to the closest exit point.

Ah ha, that's what i didn't know, makes sense. I was just thinking it would still condust to the adjacent wires as you said, but now i get it - the circuit, the fields, never thought about it before.

 

New motor ordered. $130.

 

The thing was impossible to disassemble, the squirrel cage would not come off. no screws, heated it with a torch in case it was glued, plastic was bubbling and began to melt..wouldn't budge...drilled all over the place, no dice...sad to throw it away when it only needed a bearing. i eventually cut the rear of the case and removed the bad bearing in the back but by this time new just made more sense. I'll be cracking the wheel off with a hammer to at least learn how it's attached.

[ShawnW]

I have an electric motor repair guy here and most yellow pages do too.