I noted that the motor turns easily and all rollers, etcetera are moving freely and the belt has been lubricated.
Have you changed the brushes yet?
My hypothesis is that the motor's insulation resistance is decreasing as it warms up, most markedly when the treadmill is on load (and a significant load at that
).
As a result, the earth leakage current of the motor is increasing with time(temperature) and of course is added to the normal earth leakage of the EMI filter. I guess the motor controller is a PWM type since motor is a PM one.
It is observed that the RCBO does not trip when the treadmill is run unloaded - thus much decreased work by the motor, less Ohmic heating heat, less temperature rise, less motor earth leakage....total earth leakage does not then cause the the RCBO to trip.
When run hot or hotter than designed, a motor's insulation resistance can be expected to reduce over time.
By the by, there may be a secondary effect of high temperature causing the demagnetisation over its lifetime of the motor's permanent magnets - the result would be that a higher armature current would be required to create the same torque...thus more Ohmic heating.....
I think you are at the stage of asking a motor specialist to test out the motor.
When we perform insulation resistance tester,temperature winding effected the accuracy of Mega Ohms reading.The basic theory is when temperature increase,the insulation resistance decrease due to physical factor of material for winding. To get a accurate reading for insulation resistance ( Mega...
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