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, C22.1-18, Section 10, Grounding and Bonding.

Questions? Contact us!

LINETRAXX® NGRM500
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, C22.1-18, Section 10, Grounding and Bonding.

Questions? Contact us!

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

LINETRAXX® NGRM500 Variant(s)

TypeSupply voltage U/ Frequency range HzArt. No.
NGRM500AC 48…240 V, 40…70 Hz
DC 48…240 V
B94013500

Optional Accessories for LINETRAXX® NGRM500

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® NGRM500

NameCategorySizeLanguageTimestampD-/B-Number
NGRM5x0 SW 2024-04 Software 13.8 MB EN2024/04/1919.04.2024
NGR Product Comparison Flyers 630.6 KB EN2022/07/1818.07.2022
NGRM CE Declarations of Conformity 88.5 KB 2023/05/0303.05.2023
NGRM…-Modbus Manuals 443.2 KB EN2022/06/0909.06.2022D00292
How to Size an NGR (US) Technical Information 424.0 KB EN2019/05/1313.05.2019
NGRM500/NGRM550 Quickstarts 1.1 MB EN2024/02/0707.02.2024D00373
NGRM500/NGRM550 Manuals 1.1 MB EN2024/02/2626.02.2024D00373
NGRM500 Guideform Specification (US) Technical Information 141.3 KB EN2020/04/3030.04.2020
NGR Checklist (US) Technical Information 245.3 KB EN2022/11/0707.11.2022
Guideline on NGR/Safety Ground Monitoring Technical Information 234.7 KB EN2019/09/2020.09.2019
NGRM500 Retrofit Guide (US) Technical Information 1.3 MB EN2021/02/1010.02.2021
Guideline on NGRM Relay Testing Technical Information 522.3 KB EN2021/10/2626.10.2021
HRG & LRG Systems (US) Product Brochures 5.2 MB EN2020/03/0505.03.2020
Neutral Grounding Resistor Monitors (US) Flyers 343.7 KB EN2020/03/2323.03.2020
NGRM500/NGRM550 Datasheets 1.2 MB EN2023/06/2020.06.2023D00373
NGRM550 & NGRM750 Flyers 630.6 KB EN2022/05/2525.05.2022