About the BFA Series Fuse Status Indicator from the ATC Diversified Electronics division of Marsh Bellofram: With nominal 3-phase line voltage applied, a flashing green NORMAL LED gives positive indication of a good fuse and integrity of the wire connection to each side of the fuse. A flashing red FAULT LED gives positive indication of an unconnected or open fuse, or a BFA wiring fault that needs corrected such as a lost connection to either side of the fuse or mismatched line and load wires.
When phase loss occurs, both FAULT and NORMAL LEDS will extinguish. The BFA will continue to indicate the status of the fuse during a phase loss if a regenerated voltage is produced on the open phase from a rotating motor.
