Control Panels and Contactors

Greetings,

1000 ways to skin a cat, none right and none wrong, just different.

I would like to help, but I will need more info before I can give any useful info.

What MFG of contactor are you referring to, are the controls set up for a 3 wire start/stop, two wire switch control, with or with out limit switches?

What size contactor, what is the control voltage/coil voltage?

What is the FLA on the motor?

T.

Simple. Connect the contactor coil in series with Thermal Over Load relay NC contact.

An example using a 460V 3phase power drop, use a 460V 3 phase-to-24VDC power supply for the control voltage. The control element (a switch in your case or PLC output in our case) is wired in series with the motor overload and contactor coil. Look for a monitoring contact on the overload that can be wired using the control voltage to turn on a OVERLOAD FAULT light (or PLC input). We also use a monitoring contact on the contactor itself to acknowledge that the contactor is turned on when the control voltage is applied.

In general the keyswitch and lights are wired into the coil circuit of the contactor, (Starter), which contains the thermal overload elements. (These last open the motor
circuit or may open the coil circuit on overload.)

Depending on the control voltage and system, L1 to ground, or L1 to L2 are the primary for the control transformer. Some times L1 to groung is the control voltage. Find out.