Patent ID: 6433698
Filing Date: 2002-08-13
Classification: G01R

Abstract:
A fault indicator for indicating the occurrence of a fault current in an electrical conductor, comprising:a housing; a battery; a lamp operable from said battery and viewable from the exterior of the housing; a magnetic circuit including a magnetic pole piece, a magnetically actuated switch and a bias magnet, said bias magnet having a magnetic polarity which opposes a magnetic field in said magnetic pole piece in one direction, and reenforces a magnetic field in said magnetic pole piece in the other direction, whereby said magnetically actuated switch is conditioned to open in response to a magnetic field in said one direction and closed in response to a magnetic field in said other direction; circuit means including a magnetic winding in magnetic communication with said magnetic pole piece and responsive to the current in the monitored conductor for developing a magnetic field in said pole piece in a direction to condition said switch open during normal current flow in the monitored conductor, and for developing a magnetic field in said pole piece in said opposite direction to condition said switch closed upon occurrence of a fault current in the conductor; and said magnetically actuated switch connecting said battery to said lamp whereby said lamp lights in said fault indicating state.