NM10, NM20 — induction and synchronous motor protection relays
NM10 and NM20 are digital relays of the PRO-N family for protection of electric motors in medium- and low-voltage networks. NM10 is intended for small and medium-power motors, NM20 for large induction and synchronous machines in MV networks. They are used on pumps, fans, compressors, crushers and mills.
- NM10
- small and medium motors in radial MV and LV networks; 49MG, 51LR(48)/14, 66, 46, 37, 50/51, 50N/51N, breaker failure protection, 74CT, 74TCS
- NM20
- large induction and synchronous motors in MV networks; 27, 27D, 37P, 37, 40, 47, 55, 66, 67N, 81, breaker failure protection
- Option
- function 26, temperature via Pt100
- Certificate
- IEC 61850 (PRO-N NM20)
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
NM10 is intended for small and medium-power motors in radial medium- and low-voltage networks. It is installed on lines of various lengths in networks with a solidly earthed or low-resistance earthed neutral, and on short lines in networks with an isolated neutral or a neutral earthed through an arc suppression reactor or a high-resistance resistor. The standard set of NM10 covers undercurrent protection, negative-sequence current protection, a specialized motor/generator thermal model (49MG), phase and zero-sequence overcurrent protection, locked rotor protection (51LR(48)/14), start count limiting with restart inhibit (66), breaker failure protection, CT supervision and trip circuit supervision.
NM20 is intended for large induction and synchronous motors in medium-voltage networks and works on lines of any length with an isolated or solidly earthed neutral, or a neutral earthed through an arc suppression reactor and/or resistor. The standard functions of NM20 include undervoltage and positive-sequence undervoltage protection, directional underpower protection (37P), undercurrent protection, loss of excitation protection (40) for synchronous machines, negative-sequence overvoltage protection, minimum power factor protection (55), start count limiting with restart inhibit (66), directional earth fault protection, overfrequency and underfrequency protections, and circuit breaker and trip circuit supervision.
In both relays function 26, thermal protection based on machine temperature measured by Pt100 sensors, can optionally be integrated. Additional hardware and software packs extend the configuration options, and the relays are configured in ThyVisor software. An IEC 61850 conformity certificate has been published for NM20. The specification for NM10 also lists codes 46, 37, 50/51, 50N/51N, 74CT and 74TCS, and for NM20 codes 27, 27D, 37, 47, 67N and 81.
The relays are installed on motors of pumps, fans, compressors, crushers and mills at power plants and in water supply, chemical, metallurgical and mining industries. For complex tasks with motor differential protection, the XMR-D terminal is intended.
Technical specifications
| NM10 | small and medium motors in radial MV and LV networks; 49MG, 51LR(48)/14, 66, 46, 37, 50/51, 50N/51N, breaker failure protection, 74CT, 74TCS |
|---|---|
| NM20 | large induction and synchronous motors in MV networks; 27, 27D, 37P, 37, 40, 47, 55, 66, 67N, 81, breaker failure protection |
| Option | function 26, temperature via Pt100 |
| Certificate | IEC 61850 (PRO-N NM20) |
Request a price and lead time
NM10, NM20 — induction and synchronous motor protection relays. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
Which motors is NM10 intended for?
Small and medium-power motors in radial medium- and low-voltage networks. The set includes the 49MG thermal model, locked rotor protection 51LR(48)/14 and start count limiting (66).
Which NM20 functions are needed for synchronous motors?
Loss of excitation protection (40), minimum power factor protection (55) and directional underpower protection (37P).
Does the relay have an IEC 61850 certificate?
An IEC 61850 conformity certificate has been published for NM20.
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