Originally Posted by
zephyr9900
Is there such a thing as a sticky contactor? They seem to me to be a kind of heavy-duty relay, and I know relays can have sticky contacts. Are there any other problems contactors can have? I don't think it is a case of low voltage, because the other contactors always work reliably.
It should be easy to trouble shoot by measuring the coil voltage, what does the contactor coil use voltage? AC DC?
If a AC contactor does not fully pick up, i.e. the armature sticks, the coil will either over heat or burn out.
If DC then it may not be fully engaging, again, I would trouble shoot using voltage measurements first.
If this is a new contactor, it is unlikely that you have burnt contacts, in a VFD type application, the contactor should pick up under relatively low load,
as the spindle motor command should occur after pick up.
Systematic trouble shooting by voltage readings should pin-point the problem.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.