LINETRAXX® NGRM550
The NGRM550 Neutral Grounding Resistor Monitor detects grounding-resistor failures and ground faults. It is intended for use in low-resistance grounded transformers and generators used in commercial and industrial power systems. This versatility makes the NGRM550 an essential component in enhancing ground fault protection and electrical safety. In these systems, the NGRM550 monitors:
- Current through the neutral-grounding resistor
- Voltage between the star point of the transformer and ground (voltage drop across the NGR)
- NGR failure (open), including failure of connections between neutral and ground
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 an ideal solution that is easy to retrofit into existing LRG (low resistance grounding) applications or factory-install in new LRG packages. If customers prefer, they can easily program the relay via the built-in webserver. NGRM550’s can easily connect to a supervisory system with Modbus TCP/IP or RTU communications. Capabilities extend to 25 kV and 2,000 A.
![[Translate to Canadian English:] NGRM550](/fileadmin/_processed_/1/0/csm_NGRM550_WEB_debfd7ed60.jpg "[Translate to Canadian English:] NGRM550")
The NGRM550 Neutral Grounding Resistor Monitor detects grounding-resistor failures and ground faults. It is intended for use in low-resistance grounded transformers and generators used in commercial and industrial power systems. This versatility makes the NGRM550 an essential component in enhancing ground fault protection and electrical safety. In these systems, the NGRM550 monitors:
- Current through the neutral-grounding resistor
- Voltage between the star point of the transformer and ground (voltage drop across the NGR)
- NGR failure (open), including failure of connections between neutral and ground
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 an ideal solution that is easy to retrofit into existing LRG (low resistance grounding) applications or factory-install in new LRG packages. If customers prefer, they can easily program the relay via the built-in webserver. NGRM550’s can easily connect to a supervisory system with Modbus TCP/IP or RTU communications. 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
- 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
- Range of use up to 2,000 m AMSL
- Fault/history memory
- Analog 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® NGRM550 Variant(s)
| Type | Supply voltage US / Frequency range Hz | Art. No. |
|---|---|---|
| NGRM550 | AC 48…240 V, 40…70 Hz DC 48…240 V | B94013550 |
Optional Accessories for LINETRAXX® NGRM550
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® NGRM550
| Name | Category | Size | Language | Timestamp | D-/B-Number |
|---|---|---|---|---|---|
| NGRM550 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 | |
| NGRM…-Modbus | Manuals | 443.2 KB | EN | 2022/06/0909.06.2022 | D00292 |
| NGRM500/NGRM550 | Datasheets | 1.2 MB | EN | 2023/06/2020.06.2023 | D00373 |
| NGRM500/NGRM550 | Quickstarts | 1.1 MB | EN | 2024/02/0707.02.2024 | D00373 |
| NGRM500/NGRM550 | Manuals | 7.4 MB | EN | 2024/09/1818.09.2024 | D00373 |
| NGR Checklist (US) | Technical Information | 245.3 KB | EN | 2022/11/0707.11.2022 |