LINETRAXX® NGRM500

The NGRM500 Neutral Grounding Resistor Monitor detects grounding-resistor failures and ground faults. It is intended for use in high-resistance grounded transformers and generators used in commercial and industrial power systems. In these systems, the NGRM500 monitors:

• Current through the neutral-grounding resistor (NGR)
• Voltage between the star point of the transformer and ground (voltage drop across the NGR)
• NGR failure (open and short), including failure of connections between neutral and ground

The NGRM500 can display the measured values, including current and voltage harmonics on the human machine interface (HMI). Users are able to select filters for ground-fault current and NGR voltage to prevent nuisance operation in noisy applications. 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 a compact design with DIN rail mounting making it easy to retrofit into existing HRG applications or factory-install in new HRG packages. If customers prefer, they can easily program the relay via the built-in webserver. NGRM500’s can easily connect to a supervisory system with Modbus TCP/IP or RTU communications. Capabilities extend to 25 kV and 100 A.

The NGRM500 allows the user to meet Canadian requirements. It can be used to perform the functions required by Rule 10-302, Use of Impedance Grounded Systems, of the CE Code, C22.1-21, Section 10, Grounding and Bonding.