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Finding Siemens 3RT coil voltage

Finding Siemens 3RT coil voltage
To determine the correct coil voltage for your Siemens 3RT contactor, follow the steps below.


Each Siemens 3RT1 contactor comes with a specific coil voltage and voltage code that will match the control voltage of your application.  This is not to be confused with the line voltage, which usually is 480v and only applies to the voltage of you 3 power poles.  The coil voltage, or control voltage, is what actuates or enables your coil to operate the 3RT contactor.

To find this coil voltage, you will need to look on the top of the contactor behind the three screws that you see on the front of the contactor (click here for a picture of where to find the coil voltage).  Now in between two screws is a plastic piece which is your coil and will have the coil voltage listed (examples are 24v 50/60Hz, 110v50Hz/120v60Hz, etc).  Once you have this voltage, you can select the appropriate contactor.
Technical Specifications
  • Most common coil voltages are 24vAC, 110/120vAC, 208vAC and 220/240vAC
  • Make sure you know whether your coil voltage is AC or DC rated
  • Selecting the wrong coil voltage will destroy the coil and make the contactor inoperable
  • Coils can be replaced on all SIZE S0 contactors and above