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What is the need of using a Line contactor with Soft Starter ?

We recommend the use of line contactor with the soft starter for the below reasons:
 
1-To have the line contactor as the method of switching the supply power to the starter due to contactor’s high mechanical durability compared with circuit breaker which is used for protection purpose not switching
2-You can connect R1 relay to the line contactor supply sequence in order that the circuit opens in case of fault, R1 relay can be configured as:
Fault Relay: Relay R1 is activated when the starter is powered up (minimum CL1/CL2 control).
Relay R1 is deactivated when a fault occurs and the motor switches to freewheel mode.
 
Isolating relay. Relay R1 is designed to control the line contactor on the basis of the RUN and
STOP commands and to indicate faults. Relay R1 is activated by a RUN command (or a
preheating command). It is deactivated at the end of braking or deceleration or when the
motor switches to freewheel mode after a STOP command. It is also deactivated when a fault
occurs. The motor switches to freewheel mode at this point.
 
3-To comply with our Coordination tables in accordance with standards IEC 60947-4-1 and IEC 60947-4-2, Line contactors are specified as per the attached catalog pages
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