I am designing an application with field mountable IP65 VFDs. I'm looking at using a Group Motor Installation configuration per NEC 430-53. Does this code only apply to Contactors as the motor controlling device or would VFDs apply as well? If it does, how would you size that main breaker.
e.g. I have three 1HP motors and VFDs on field. The VFD recommends a 10A breaker. Would the main breaker be 30A? Or would I size it according to the motor FLA?
In front of every VFD I was thinking of having an Enclosed MMP (Manual Motor Protector) to cover the requirements for 1) Disconnect, 2) Short Circuit/Ground Protection, 3) Overload (redundant since VFD is overload protected). Again should this be sized by the 10A VFD requirement or the motor FLA?
Any thoughts/suggestions?
e.g. I have three 1HP motors and VFDs on field. The VFD recommends a 10A breaker. Would the main breaker be 30A? Or would I size it according to the motor FLA?
In front of every VFD I was thinking of having an Enclosed MMP (Manual Motor Protector) to cover the requirements for 1) Disconnect, 2) Short Circuit/Ground Protection, 3) Overload (redundant since VFD is overload protected). Again should this be sized by the 10A VFD requirement or the motor FLA?
Any thoughts/suggestions?
