NGR Sensing Resistors are attached in parallel to the Neutral Grounding Resistor. The sensing resistor allows a protective relay which detects resistor failure in a continuous manner.
Sensing Resistors are used in combination with neutral grounding resistor monitor relays. The relay measures NGR resistance, NGR current and neutral to ground voltage. The relay continuously measures NGR ohmic value in an unfaulted system and it trips on, providing a warning, if NGR resistance varies from its calibrated value.
Sensing Resistors are used to continuously monitor the voltage drop on the neutral grounding resistor continuously and in case of a continuity failure on the NGR, the monitoring relay trips based on the preset current and time.
Hilkar sensing resistors are used both for sensing resistor purposes to monitor the NGR for continuity as well as a resistive voltage divider. When they are used as resistive voltage dividers, voltage measurement is obtained through the R1 and R2 terminals of the resistive voltage divider.