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.
![[Translate to Canadian English:] NGRM750](/fileadmin/_processed_/c/c/csm_NGRM750_WEB_f1d049cc53.jpg "[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.
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)
| Type | Supply voltage US / Frequency range Hz | Art. No. |
|---|---|---|
| NGRM750 | AC 24…240 V, 40…70 Hz DC 24…240 V | B94013750 |
Optional Accessories for LINETRAXX® NGRM750
CD-series coupling device
| Type | Voltage Usys | Art. No. |
|---|---|---|
| CD1000 | 400…690 V | B98039010 |
| CD1000-2 | 400…1000 V | B98039053 |
| CD5000 | 1000…4200 V | B98039011 |
| CD14400 | 4300…14550 V | B98039054 |
| CD25000 | 14551…25000 V | B98039055 |
Measuring current transformer
| Type | Voltage/Current | Art. No. |
|---|---|---|
| CTAC35 CTAC60 CTAS50 CTAS80 CTAS120 | AC up to 30 A | B98110007 B98110017 B98110009 B98110010 B98110011 |
| CTUB103-CTBC35 | AC/DC up to 10 A | B78120030 |
| CTUB103-CTBC60 CTUB103-CTBC120 | AC/DC up to 25 A | B78120031 B78120032 |
| CTB31…CTB51 series | AC > 30…1000 A | B980860xx |
Voltage supply for measuring current transformers CTUB103…
| Type | max. connected measuring current transformers | Art. No. |
|---|---|---|
| STEP-PS/1 AC/24 DC/0.5 | 2 | B94053110 |
| STEP-PS/1 AC/24 DC/1.75 | 7 | B94053111 |
| STEP-PS/1 AC/24 DC/4.2 | 17 | B94053112 |
Downloads for LINETRAXX® NGRM750
| Name | Category | Size | Language | Timestamp | D-/B-Number |
|---|---|---|---|---|---|
| NGRM750 Update V4.00 | Software | 8.1 MB | 2024/04/2323.04.2024 | ||
| NGR Product Comparison | Flyers | 630.6 KB | EN | 2022/07/1818.07.2022 | |
| NGRM700/NGRM750 | Quickstarts | 1.4 MB | EN | 2022/12/0202.12.2022 | D00292 |
| NGRM700/NGRM750 | Datasheets | 1.0 MB | EN | 2023/07/3131.07.2023 | D00292 |
| NGRM700/NGRM750 | Manuals | 7.6 MB | EN | 2024/09/1818.09.2024 | D00292 |
| NGRM550 & NGRM750 | Flyers | 630.6 KB | EN | 2022/05/2525.05.2022 | |
| NGRM…-Modbus | Manuals | 443.2 KB | EN | 2022/06/0909.06.2022 | D00292 |
| NGR Checklist (US) | Technical Information | 245.3 KB | EN | 2022/11/0707.11.2022 |