Rockwell Automation 7763 Medium Voltage OneGear SMC Flex Motor Controller (10-15 kV) - Manual (Page 18)

18 Rockwell Automation Publication 7760-UM001D-EN-P - October 2014
Chapter 1 Product Overview
Power Factor Correction Capacitors
OneGear SMCs can be installed on a system with power factor correction
capacitors. These capacitors must be installed on the line side of the Power
Converter to prevent damage to the SMC Flex Controller silicon-controlled
rectifiers (SCR). A separate switching contactor or breaker is required for the
power factor correction capacitors. This switching device closes only after the
bypass contactor has closed. The power factor correction capacitors must also be
opened before the bypass contactor is opened to perform a stop function.
When discharged, a capacitor as essentially zero impedance. Therefore,
impedance must be added in series with the capacitors to limit inrush current.
Acceptable optional PFCC connection methods for Bulletin 7760, 7762, and
7763 are shown in
Figure 5 , Figure 6 , and Figure 7 . The same concept applies to
Bulletin 7761.
Figure 5 - Typical OneGear Single Line Diagram Bulletin 7760 (10…14.4 kV) with two optional
Power Factor Correction Capacitor positions (Vacuum Breaker)
TIP Consult the factory is there are capacitors on the same branch circuit as the
OneGear SMC.
WARNING: Do not connect power factor correction capacitors in the circuit
when OneGear SMC SCRs are gating.
Power Converter Bypass Controller Optional PFCC
Breaker
Fused
Contactor
PFCC
SMC Flex
Control
Module
R, S, T R, S, T
R, S, T R, S, T
U, V, W
M
R, S, T
R, S, T
Fused
Contactor
PFCC
Optional PFCC Cable Connection Point Existing Controller
Breaker
Optional
Earthing
Switch