For field installations of branch circuits supplying multiple motors rated more than 1 hp, 430.53(B) permits a common short-circuit and ground-fault protective device, provided that each motor is equipped with individual overload protection. This section also specifies that the conditions of operation must ensure that the SCGF device will not open under the most severe conditions of normal operation.

Based on this requirement, it is up to the user to select the proper SCGF device to accomplish this objective. In regard to the use of an instantaneous trip circuit breaker to provide the SCGF protection for branch circuits supplying more than one motor, it should be noted that the use of such devices must meet all the requirements specified in 430.52(C)(3) (including that for coordinated motor overload/SCGF protection) and any requirements for the application that might be specified in the installation instructions.