Grounding resistor monitoring system LINETRAXX® NGRM550

transformerEthernetModbus

The NGRM550 Neutral Grounding Resistor Monitor detects grounding-resistor failures and ground faults. It is intended for use in low-resistance grounded transformers and generators used in commercial and industrial power systems. In these systems, the NGRM550 monitors: • Current through the neutral-grounding resistor • Voltage between the star point of the transformer and ground (voltage drop across the NGR) • NGR failure (open), including failure of connections between neutral and ground A benefit to many users is the multilingual user interface that allows the comfort of reading values and programming in your native language. It is an ideal solution that is easy to retrofit into existing LRG applications or factory-install in new LRG packages. If customers prefer, they can easily program the relay via the built-in webserver.  NGRM550’s can easily connect to a supervisory system with Modbus TCP/IP or RTU communications. Capabilities extend to 25 kV and 2,000 A. • Determination of RNGR with passive and active measurement methods • Continuous monitoring of the RNGR even if the installation is de-energized • Alarm or trip on ground fault • Monitoring of the current INGR • Monitoring of the voltage UNGR • Ethernet communication • Webserver • Language selection (English, German, Spanish, French) • Test button (internal, external) with/without tripping • FFT analysis of the measuring signals • 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 2,000 m AMSL