I was curious what method others use to provide coordination settings for an MCC Main breaker of Feeder breaker (If MCC is MLO).
Per the red book when modeling motors in an MCC motors 50hp or less are typically lumped into a single lump sum while motors over 50hp are represented seperately. Assuming that we are dealing with an MCC that has several motors under 50hp lumped together and single motors over 100hp represented seperately how do you typically go about setting the MCC main breaker?
Do you typically set the breaker to allow for some combination of the motors in the MCC starting? Largest motors? Largest 2 motors? Lump sum starting?
Do you try to coordinate the main breaker with the largest MCP in the MCC, accounting for the adjustable instantaneous setting on the MCP.
Just curious to hear what others do or have done when performing a coordination study, in order to derive settings for an MCC main or feeder breaker.
Thanks
Per the red book when modeling motors in an MCC motors 50hp or less are typically lumped into a single lump sum while motors over 50hp are represented seperately. Assuming that we are dealing with an MCC that has several motors under 50hp lumped together and single motors over 100hp represented seperately how do you typically go about setting the MCC main breaker?
Do you typically set the breaker to allow for some combination of the motors in the MCC starting? Largest motors? Largest 2 motors? Lump sum starting?
Do you try to coordinate the main breaker with the largest MCP in the MCC, accounting for the adjustable instantaneous setting on the MCP.
Just curious to hear what others do or have done when performing a coordination study, in order to derive settings for an MCC main or feeder breaker.
Thanks