I have a treadmill incline motor that is blowing its circuits fuse every time it starts to run. This is the motor that lifts the treadmill up and down.
The motor is labeled:
Output: 65W
Input 36VDC
Current: 3A
Speed: 3700 RPM
Torque: 1.7KG-CM
I tested the voltage off the board and it's correct per the manual. I have visually inspected the motor, taking the commutator out and it looks OK. I've performed the 3 tests (180 degree resistance, bar to bar resistance and bar to stack) here: http://www.groschopp.com/how-to-check-a-motor-armature/
Everything seems ok.
I did some other "cowboy" tests, which I doubt the validity:
- I hooked the bell end (end with brushes, I think it's called bell
end) to the board by itself. It's still an open circuit and sure
enough the fuse stayed fine. No surprise. I left the bell end hooked
up and I put the commutator in, alone without the housing. - With the brushes contacting the commutator the fuse immediately blew when
voltage was applied.
The resistance across for the 180 degree test was 2.5 ohm. That resistance doesn't work with the watts and voltage.
Is this motor bad? Shorted out somewhere? Or am I missing something?
Best Answer
DC motor current ratings are occasionally specified as their no-load current draw.
I would assume that the motor will draw considerably more power when it's starting, or if it's heavily loaded.
What kind of fuse is it blowing? If it's a fast-blow fuse, I would expect it to fail every time the motor starts.