motor monitoring for fault detection

[rutman]

I'd like to have provision on my machine such that it cannot destroy itself.
Is there a known way to look at the motor currents and determine that there is a problem (e.g. from unusually high currents?)

Then on the mechanical side, perhaps I can use some replaceable component that has been designed to be the weakest link, such that in a real screwup the replaceable component breaks instead of something important (as in the 'ear' connecting a mountain bike derailleur to the bike)

Are there for instance couplers (e.g. motor shaft to screw shaft) that are designed to break at a certain torque?


Thanks
Jeremy Rutman

[john_100]

Hi Jeremy ,

yes ,it all depends on the motor you want to protect

there is various mechanical fuses eg. shear pins or plastic gears that break
or slipping clutch torque limiters

for a mains powered ac motor you have a thermal overload switch
at least to switch off contactor

electronic speed controllers can either limit the motor current or switch off
depending on the overload current (and the design of the controller)

don't forget on cnc machines the limit switches to prevent you hitting the mechanical end stops

John