ZJJ Series Insulation Monitoring Relay

ZJJ DC insulation monitoring relay monitorsthe insulation of the DC bus, and it sendsalarm signal when the bus-to-groundinsulation drops to a certain value,also it ispanel mounted type,and the relay has a high-sensitivity grounding resistance monitoringand display circuit, it is great significance forthe safe operation of the DC system.

ZJJ Series Insulation Monitoring Relay
ZJJ Series Insulation Monitoring Relay


·Monitoring of the DC circuit bus barinsulation resistance RF to earth.
·LCD screen display resistance value.
·Bridge balance method for resistancemeasurement.
·Adjustable response value ranges of 0-100kΩ.
·Smaller short-circuit grounding current forsafe operation.


Model ZJJ-4S
Input voltage 300-1200VDC
Power supply voltage 90-150VDC
Power supply current 7-20mA
Operating temperature -40°C ~ 70°C, 85%
Measuring resistance 0~199.9KΩ
Precision V=220V (5%)
Short circuit ground current V=220V (2mA)
Alarm setting range 0~100KΩ
Action return factor Rs=50KΩ(95%-98%) 
Output contact capacity Sensitive load=5mS(DC220V0.2A)
Resistive load(DC220V 2A)
Installation type Panel mount



·DC or AC/DC main circuits.·UPS systems, battery systems.
·IT systems with high leakage capacitances.·DC charging stations for electric vehicles.