LINETRAXX® NGRM750

The NGRM750 Neutral Grounding Resistor Monitor detects grounding-resistor failures and ground faults and monitors line voltages. It is intended for use in low-resistance grounded (LRG) commercial and industrial power systems. It is an advanced device that allows monitoring of :

  • Current through the neutral-grounding resistor (NGR)
  • Voltage between the transformer or generator neutral point and ground (voltage drop across the NGR)
  • NGR failure (open), including failure of connections between neutral and ground
  • Line-to-line and line-to-ground voltages

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 designed for easy retrofit with a panel mountable human-machine interface (HMI).  If preferred, the relay can easily be programmed via the built-in webserver.  NGRM750’s can easily connect to a supervisory system with Modbus TCP/IP or RTU communications.

For generator or transformer grounding applications at extreme altitudes, the NGRM750 features a 5,000 m above sea level capability.

It is an ideal solution that is easy to retrofit into existing LRG applications or factory-install in new LRG packages. Capabilities extend to 25 kV and 2,000 A.

Questions? Contact us!

[Translate to Canadian English:] NGRM750

The NGRM750 Neutral Grounding Resistor Monitor detects grounding-resistor failures and ground faults and monitors line voltages. It is intended for use in low-resistance grounded (LRG) commercial and industrial power systems. It is an advanced device that allows monitoring of :

  • Current through the neutral-grounding resistor (NGR)
  • Voltage between the transformer or generator neutral point and ground (voltage drop across the NGR)
  • NGR failure (open), including failure of connections between neutral and ground
  • Line-to-line and line-to-ground voltages

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 designed for easy retrofit with a panel mountable human-machine interface (HMI).  If preferred, the relay can easily be programmed via the built-in webserver.  NGRM750’s can easily connect to a supervisory system with Modbus TCP/IP or RTU communications.

For generator or transformer grounding applications at extreme altitudes, the NGRM750 features a 5,000 m above sea level capability.

It is an ideal solution that is easy to retrofit into existing LRG applications or factory-install in new LRG packages. Capabilities extend to 25 kV and 2,000 A.

Questions? Contact us!

Features

  • 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
  • Faulted-phase indication (optional; up to 690 V direct coupling, otherwise via potential transformers)
  • 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 (24 to 240 VAC/VDC)
  • Range of use up to 5,000 m AMSL
  • Fault/history memory
  • Analog output of measured values (0…10 V, 4…20 mA, etc., selectable parameters)
  • Detachable HMI for door mounting
  • Password protection
  • Tripping on RMS, fundamental component signal or harmonics
  • Detection of AC and DC ground faults

LINETRAXX® NGRM750 Variant(s)

TypeSupply voltage U/ Frequency range HzArt. No.
NGRM750AC 24…240 V, 40…70 Hz
DC 24…240 V
B94013750

Optional Accessories for LINETRAXX® NGRM750

CD-series coupling device

TypeVoltage UsysArt. No.
CD1000400…690 VB98039010
CD1000-2400…1000 VB98039053
CD50001000…4200 VB98039011
CD144004300…14550 VB98039054
CD2500014551…25000 VB98039055

Measuring current transformer

TypeVoltage/CurrentArt. No.
CTAC35
CTAC60
CTAS50
CTAS80
CTAS120
AC up to 30 AB98110007
B98110017
B98110009
B98110010
B98110011
CTUB103-CTBC35AC/DC up to 10 AB78120030
CTUB103-CTBC60
CTUB103-CTBC120
AC/DC up to 25 AB78120031
B78120032
CTB31…CTB51 seriesAC > 30…1000 AB980860xx

Voltage supply for measuring current transformers CTUB103…

Typemax. connected measuring current transformersArt. No.
STEP-PS/1 AC/24 DC/0.52B94053110
STEP-PS/1 AC/24 DC/1.757B94053111
STEP-PS/1 AC/24 DC/4.217B94053112

Downloads for LINETRAXX® NGRM750

NameCategorySizeLanguageTimestampD-/B-Number
NGR Product Comparison Flyers 630.6 KB EN2022/07/1818.07.2022
NGRM700/NGRM750 Quickstarts 1.4 MB EN2022/12/0202.12.2022D00292
NGRM700/NGRM750 Datasheets 1.0 MB EN2023/07/3131.07.2023D00292
NGRM700/NGRM750 Manuals 1.2 MB EN2024/02/2626.02.2024D00292
NGRM550 & NGRM750 Flyers 630.6 KB EN2022/05/2525.05.2022
NGRM…-Modbus Manuals 443.2 KB EN2022/06/0909.06.2022D00292
NGR Checklist (US) Technical Information 245.3 KB EN2022/11/0707.11.2022