Browse FAQs

How do I connect a shorting contactor to an ATS48 soft starter without using an interposing relay?

Published date: 08 May 2019

Issue:
Customer has an ATS48 soft starter and wants to connect a shorting contactor without using an interposing relay.

Product Line:
ATS48

Environment:
ATS48 soft starters with shorting contactor where the coil current of the shorting contactor does not exceed the ratings of the R2 relay contacts of the starter.

Cause:
Information in current literature is vague in this situation.

Resolution:
The R2 relay of the ATS48 soft starter is a dedicated purpose relay.  It will be used to switch on and off the coil voltage for the shorting contactor.  It can not be assigned to any other function.
The R2 relay has the following limitations:

Minimum Switching Capacity: 10 mA for 6Vdc
Maximum switching capacity on inductive load:
1.8 A for 230 Vac and 30Vdc
Maximum voltage 400Vac.

Make sure that the coil voltage / current requirements of your shorting contactor do not exceed the above ratings.  If they do then an interposing relay is necessary to prevent damage to the soft starter internal circuitry.  Please see FA234738 for installing a shorting contactor with an interposing relay.

You will need to provide external voltage to the R2C terminal.  The voltage should be compatible with the coil of your shorting contactor.
Connect R2A of the soft starter to one side of the coil of your shorting contactor.
Connect the other side of your shorting contactor coil to  the common / neutral for the power supply used to power the R2C terminal.
Connect line 1,2 and 3 of your shorting contactor to line 1,2, and 3 of your incoming three phase power.
Connect load lines 1,2, and 3 of your shorting contactor to terminals A2, B2, and C2 on the bottom of the soft starter.  OBSERVE PHASE ROTATION. Do not cross the phases.  

Note that there are no programming changes necessary in the starter to enable the shorting contactor.   Once the ACC time has been reached and the motor current measured by the starter is below 110% of the motor FLA rating, the starter will close the R2 relay and send power to the coil of your shorting contactor.

 

Was this helpful?

What can we do to improve the information ?

Can't find what you are looking for?

Reach out to our customer care team to receive information on technical support, assistance for complaints and more.