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PCS and PF Softstarter Load Side voltage

Question:

Why is there voltage present on the load side terminals when using an PF/PCS soft starter and the motor is stopped with three phase power supplied to the input side of the controller?

Answer:

The leakage current through the SCR's cause voltage to be present. This voltage could be equal to the line voltage depending on how it is measured. The current is not enough to start the motor.

When using a three lead motor, verify the motor leads are connected to the T1, T2, and T3 terminals on the load side of the PCS and PF soft starters.

Line Connection

Line Connection is defined as using 3 leads from the motor to the soft starter.

• For PCS products, this means that dip switch 15 is in the Up position
• For PF controllers, Parameter 15 Motor Connection is configured for Line

Delta Connection

Delta Connection is defined as the soft starter is in series with each motor winding and the wiring follows the DELTA or Inside the Delta wiring.

• For PCS products this means switch 15 is in the Off position for Delta
• For PF controllers, Parameter 15 Motor Connection is configured for Delta

It is highly recommended that the user install an Isolation Contactor when using Wye Delta 6 lead motors with the PCS and PF soft starters.