Rockwell Automation 1413-CAP-ME-PE Capacitor Bank Controller, Series C - Manual (Page 56)

56 Rockwell Automation Publication 1413-UM001D-EN-P - November 2010
Chapter 4 Operation
• Balanced (mode = 2) – This mode counts the number of opening
operations on each capacitor step and switch-capacitor steps to balance the
number of opening operations equally across all of the employed capacitor
steps. This mode is also most useful when all of the steps are of similar size.
• Best Fit (mode = 3) – This mode selects capacitor steps to be switched on
and off to most closely achieve the target power factor and kVAR needs of
the system. When the system’s kVAR needs increase, the available step or
steps with the closest (aggregated) kVAR rating is added. On decreasing
kVAR demand, steps are switched off in similar fashion.
Fault Relay Operation
Fault-protection relays can be used to immediately discharge all or specific
capacitor steps during a fault occurrence. Input 0 is wired to a normally closed
fault-protection relay and discharges all capacitor steps during a fault occurrence
(low-state condition). Inputs 1… 10 are wired to normally closed fault-protection
relays, and discharges its respective capacitor step during a fault occurrence (low-
state condition). If fault protection is not being used for a specific capacitor step,
then that respective input is wired closed by using the controller supplied
24V DC power.
A normally-open momentary pushbutton is wired to Input 11. This pushbutton
is used to reset the controller after a fault occurrence.
Output 0 is used as an alarm relay and is wired normally open to an external alarm
indicator. Outputs 1…10 are wired to normally-open contactors for each
respective capacitor step.