Differential Current Monitoring

The differential current or fault current monitoring is used in grounded systems to protect people and devices.

The protection of people and devices are done through a residual current circuit breaker.  These have the disadvantage that all connected system components are disconnected in the case of a fault.  The system then comes to a halt and can cause production losses.

For preventive maintenance differential current relays are used.  These display the current fault current through signal relays and monitor the possible current loops from the deterioration.

The information gathered here reduces the occurance of interruptions, failures, and fires.

Device Choices

Voltage Type of the Monitored SystemThreshold ValueVoltage SupplyUL
Device Type
Pure AC Voltage (50 - 60Hz)

Adjustable in 10 Steps
10mA - 3A

230VAC

NWD5220

RCD300M2

115VACX
24VDCX
Adjustable in 10 Steps
1A - 12A
230VAC
RCD300M2

115VACX
24VDCX
Pure AC Voltage (500 - 1000Hz)Fixed
10mA / 30mA
120VACXRCD310W2
24VDCX
AC & DC Components
> Sensitive to All Current Types <
Fixed
30mA
400VACRCMU200
230VAC
115VAC
24VDC