The NGRM500 is only intended for use in high-resistance grounded systems. In these systems, the NGRM500 monitors:
the current through the neutral-grounding resistor (NGR),
the voltage between the star point of the transformer and earth (voltage drop across the NGR),
the condition of the NGR.
In order to meet the requirements of applicable standards, customised parameter settings must be made on the device to configure it for local equipment and operating conditions.
Features
Determination of RNGR with passive and active measurement methods
Continuous monitoring of the RNGR even if the installation is de-energised;
Alarm or trip on ground fault
Monitoring of the current INGR
Monitoring of the voltage UNGR
Ethernet communication
Web server
Language selection (German, English GB and US, Spanish, French)
Test button (internal, external) with/without tripping
FFT analysis of the measuring signals
Pulser for manual ground fault location
Relay for detection of ground faults and resistor faults
Relay for shutdown of the installation after a configurable time
Can be combined with RCMS… for automatic shutdown of feeders
Graphical user interface
Wide supply voltage range
Range of use up to 2000 m AMSL
Fault/History memory
Analogue output of measured values (0…10 V, 4…20 mA, etc., selectable parameters)
Password protection
Tripping on RMS, fundamental component signal or harmonics
Detection of AC and DC ground faults