Bob,
The caps are wired static connection on the load side of the starters before the O\Ls.The chillers are 4160v and were screaming The draft towers,condenser,chilled and secondary water pumps are fed from a 600v MCC.
A secondary water pump cap shorted and tripped the distribution breaker instead of the main on the MCC.So much for the selective coordination.I wonder why so many of the capacitors on this on Mcc have failed?Have you seen this happen? .9 is the max pf allowed by the utility and one concern i have is high transient voltages in the motor circuit from an over corrected power factor.At what point does this occur?I took a look at the tables and the capacitors look about the right size but the tables are too general and every cap is supposed to be tailored to the individual motor.
thanks
