NM10 · MCCB
NM10 provides feeder protection and, in smaller frames, infrequent motor-start protection duties.
The 2026 source describes NM10 for 50 Hz distribution networks, working voltage to 380 V and current to 600 A. Ratings of 250 A and below can also be used for infrequent motor starting and motor overload/short-circuit/undervoltage protection.
Verified source data
Use exact trip data and fault-current requirements for final selection.
| Item | NM10 source data | Selection note |
|---|---|---|
| Frequency | 50 Hz | Confirm system frequency |
| Working voltage | Up to 380 V for the cited NM10 series description | Check exact frame/version |
| Current | Up to 600 A | Frame and trip rating must be selected separately |
| Motor use | 250 A and below may be used for infrequent motor starting/protection | Coordinate with contactor and overload relay |
| Protection | Overload, short circuit, undervoltage | Available fault current must be checked |
Motor-starter coordination
A breaker, contactor and overload relay protect different failure modes.
Do not replace the overload relay with the breaker by assumption. Upstream short-circuit protection, contactor switching duty and motor overload protection must be coordinated as a system.
Source reference
Internal database reference for engineering review.
2026 B11 compilation: NM10 detailed pages 101–106. The B12 overview does not list NM10 in its shorter MCCB summary.