My kit built belt sander, dropped down into start mode while running and shut off. Now motor won’t start.

[RaisedByWolves]

I say kit built as I pulled the machine out of a junkyard to rebuild.

I scored the motor and controls out of a Rockwell unit we were throwing out at work and installed them several years ago.

This combination was never easy to start, kinda laggy but would get there eventually. Once running it really never had the power the unit the motor came from even with similar size pullies, but it was usable as long as I didn’t push it.

Well I pushed it. It dropped out of run and into start a couple times, then the last time it quit full stop.

When I hit the power it hums and I can almost get it going kick starting it( moving belt by hand.

Would this be start cap related (hoping) or something internally to the windings?

 

[markba633csi]

Probably the cap, so unless you can measure it just replace it
Can you borrow a cap from another machine?

 

[RaisedByWolves]

Probably the cap, so unless you can measure it just replace it
Can you borrow a cap from another machine?

I have a spare from when my bandsaw was acting up.

That turned out to be the start slip ring contacts needed cleaned.

That would be simple, any other thought appreciated.

 

[markba633csi]

That could be the case here as well, eliminate the cap as a suspect if possible
Start caps can be smaller in uF value than the original, the motor will just start slower is all. It's fine for testing.
If the cap is larger the starting is very quick but the motor gets warmer and it puts a heavier load on the centrifugal switch.

 

[RJSakowski]

A bad capacitor wouldn't cause the poor run performance as the capacitor isn't in the circuit then. Given poor performance in both the dysty and run modes, I would expect either a poor connection or a shorted winding. A shorted winding causing the motor to drop into start mode could have taken out the capacitor for a double fault. A clamp on ammeter should give you a clue.

 

[benmychree]

Given the poor start and run performance, I'd make sure that it is wired for the proper voltage.

 

[markba633csi]

RJ is right- unless the motor has two caps (start and run) you may be looking at a winding problem and motor replacement