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What is our recommendations for power factor correction capacitors (PFCC) on an Altistart ATS46 or ATS48 softstart?

A capacitor placed on the output of a soft starter causes a short circuit across the SCR stacks upon startup, which may damage the SCRs. If PFCCs are required, the capacitors must be located on the line side of the ALTISTART Soft Start and should only be in the circuit while the motor is operating at full speed.  Even when applied correctly to ensure that the ALTISTART starter can maintain synchronization within the line voltage, maximum correction for power factor should not exceed 95%.
See SquareD Bulletin No. 8638PD9603R1/98

Reviewed 10/2011

CTA-ID : 7324
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