We offer you first-class quality and safety combined with global service and every support in resolving your monitoring problems.



  • Comprehensively configurable
  • Designed for easy retrofit
  • Multilingual user interface
  • Can operate on systems 5000 m above sea level without derating

The NGRM700 is an advanced device that allows continuous NGR monitoring to provide all necessary information of the system grounding.

The NGRM700 monitors the resistance value of the Neutral Grounding Resistor (NGR) and the fault current flowing through the NGR in High Resistance Grounded (HRG) systems. The ideal relay to protect HRG systems and to provide a comprehensive overview. The relay can be connected to the supervision system or directly to the communication network.

The NGRM700 allows the user to meet local requirements.


  • 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
  • Phase-to-ground fault indication (optional; up to 690 V direct coupling, otherwise via potential transformers)
  • 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 (24 to 240 Vac/Vdc)
  • Range of use up to 5000 m AMSL
  • Fault/History memory
  • Analogue 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® NGRM700 Variant(s)

TypeSupply voltage U/ Frequency range HzArt. No.
NGRM700AC 24…240 V, 40…70 Hz
DC 24…240 V
Accessory for FP200-NGRM: Transparent front cover 144x72 (for IP65)*B98060005

*When using the "transparent front cover 144x72 (IP 65)" the cutout in the switchboard cabinet must be extended in height from 66 mm to 68 mm (+0.7/-0 mm).

The degree of protection IP65 applies only to the user interface FP200-NGRM when using the front cover. The degree of protection for the complete device is still IP30.

Optional Accessories for LINETRAXX® NGRM700

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.
W20AC up to 10 AB98080003
AC up to 25 AB98080010
CTUB103-CTBC35AC/DC up to 10 AB78120030
AC/DC up to 25 AB78120031

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® NGRM700

CE Declarations of conformity NGRM 83.0 KB 2022/08/12 06:17:2512.08.2022 06:17:25
Quickstarts NGRM700/NGRM750 1.1 MB DE2022/12/02 11:08:2902.12.2022 11:08:29D00292
Quickstarts NGRM700/NGRM750 1.4 MB EN2022/12/02 11:08:3102.12.2022 11:08:31D00292
Datasheets NGRM700/NGRM750 1.0 MB DE2023/03/16 11:55:3216.03.2023 11:55:32D00292
Datasheets NGRM700/NGRM750 1.0 MB FR2023/03/16 11:57:4116.03.2023 11:57:41D00292
Datasheets NGRM700/NGRM750 1.1 MB EN2023/03/16 11:56:2516.03.2023 11:56:25D00292
Datasheets NGRM700/NGRM750 1.1 MB ES2023/03/16 11:56:5216.03.2023 11:56:52D00292
Manuals NGRM700/NGRM750 6.4 MB DE2022/12/02 11:07:2902.12.2022 11:07:29D00292
Manuals NGRM700/NGRM750 5.3 MB EN2022/12/02 11:07:5502.12.2022 11:07:55D00292
Technical information NGRM700 Guideform Specification (US) 141.8 KB EN2020/04/30 18:55:5630.04.2020 18:55:56
Technical information NGRM700 Guideform Specifications 159.5 KB ES2020/05/22 14:12:3022.05.2020 14:12:30
Manuals NGRM…-Modbus 453.9 KB DE2022/06/09 10:45:4109.06.2022 10:45:41D00292
Manuals NGRM…-Modbus 443.2 KB EN2022/06/09 10:47:4409.06.2022 10:47:44D00292
Manuals NGRM…-Modbus 463.4 KB ES2022/06/09 10:49:2509.06.2022 10:49:25D00292
Technical information How to Size an NGR (US) 424.0 KB EN2019/05/13 10:31:3513.05.2019 10:31:35
Technical information How to size an NGR (ES) 426.7 KB ES2021/05/26 11:31:0926.05.2021 11:31:09
Technical information NGR Checklist (US) 245.3 KB EN2022/11/07 16:39:0207.11.2022 16:39:02
Technical information Guideline on NGR/Safety Ground Monitoring 234.7 KB EN2019/09/20 13:52:3320.09.2019 13:52:33
Technical information Guideline on NGRM Relay Testing 522.3 KB EN2021/10/26 18:41:5226.10.2021 18:41:52
Application brochures System Grounding in the Americas, Australia, South Africa and Other Regions 576.7 KB EN2019/05/13 10:29:2213.05.2019 10:29:22
Product Brochures HRG & LRG Systems (US) 5.2 MB EN2020/03/05 21:02:3305.03.2020 21:02:33
Flyer Neutral Grounding Resistor Monitors (US) 343.7 KB EN2020/03/23 17:32:0023.03.2020 17:32:00
Product Brochures Mining 11.7 MB ES2020/05/22 14:37:3122.05.2020 14:37:31