Rockwell Automation 1560E SMC Flex Smart Motor Controller - Manual (Page 62)

2-14 Installation
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Installation (cont.) Power Factor Correction Capacitors
The controller can be installed on a system with power factor correction
capacitors. The capacitors must be located on the line side of the controller.
This is required to prevent damage to the SCRs in the MV SMC-Flex
controller. A separate switching contactor is recommended to apply the
capacitors only after the bypass contactor has closed, and to remove them
when the bypass contactor opens. See Figure 2.7 for two different
acceptable connection methods.
NOTE: Consult the factory if there are any capacitors on the same
branch circuit as the MV SMC-Flex.
When discharged, a capacitor has essentially zero impedance. For
switching, sufficient impedance should be connected in series with the
capacitor bank to limit the inrush current. A method of limiting the surge
current is to add inductance in the capacitor conductors. This can be accom-
plished by putting turns or coils of wire in the power connections to the
capacitors (6-inch diameter coil, six loops). For more information, refer
to NEMA standard ICS 2, Part 2, Capacitor Applications.
Care should be used in mounting the coils so that they are not stacked
directly on top of each other or they will have a cancelling effect. Also,
the coils should be mounted on insulated supports away from metal parts
so they will not act like induction heaters.
Any covers or barriers removed during installation must
be replaced and securely fastened before energizing
equipment. Failure to do so may result in severe burns,
injury or death.
A T T E N T I O N A T T E N T I O N