What causes a the chatter if you wire a 3 phase contactor backward, that is put the load on the "L" marked screws and the line on the "T" marked screws?

I have heard from a few electricians that the contactor should work in either direction.

Thanks in advance for your help.

 

Depends on the Contactor, If its the type held in by a solenoid which is usualy on the load side, it may not be happy.

 

I've been installing contactors for 40 years and never had one chhattterr. In fact, I use them so often that I carry several in my truck. I can only suggest that your problem is not in the contactor, or, just install it the way it wants to be installed, if that fixes the problem.

 

Is there an auxiliary contact on the contactor that might be different from the old contactor?
Reversing the load and feed sides will have no impact on the contactor, but if the auxiliary contact is NC instead of NO then it may have an impact (still nothing to do with being reversed.)