Patent ID: 9664716
Date: 2017-05-30
CPC Classifications: G01R

Claim:
1. An automatic permanently installed insulation resistance testing and monitoring apparatus for measuring insulation resistance of LV, MV and high-rated voltage, grounded or ungrounded, electrical equipment having a control cabinet used to operate said electrical equipment and that control cabinet having a door panel, the apparatus comprising: an automatic insulation resistance tester and monitoring module located in the control cabinet of the electrical equipment; a remote control display assembly located outside the control cabinet of the electrical equipment and operatively connected to the insulation resistance tester and monitoring module located in the control cabinet for operating the insulation resistance tester and monitoring module located in the control cabinet without having to open the door panel and thus potentially exposing personnel to an arc flash accident, the remote control assembly including at least an alarm reset button, a test/calibrate button, and a calibration potentiometer; and an isolation circuit which includes a secondary high voltage sensing transformer with a primary winding connected in series with a main high voltage transformer secondary winding, a blocking diode, and a resistor bridge for completely isolating HV circuitry of the insulation resistance testing and monitoring apparatus from LV circuitry of the insulation resistance testing and monitoring apparatus and providing a signal to a meter that indicates an insulation value of the electrical equipment in meg-ohms.