3-pole power circuit breaker 1250A NZMN4-AE1250 265761

3-pole power circuit breaker with 1250 A current rating, equipped with an electronic trip unit and a short-circuit breaking capacity of 37 kA

The device is fixed, mounted directly on the switchboard panel or frame — it is not suitable for DIN rail mounting or plug-in/withdrawable configurations. Main circuit terminals are located on the front side and are designed as screw connections, allowing the connection of copper conductors with a cross-section up to 300 mm² or aluminum conductors up to 240 mm². Touch protection in the control area corresponds to IP20 — meaning there is no protection against moisture or dust, and the device must be installed in an enclosure with a higher degree of protection.

The electronic trip unit allows adjustment of the overload current setting in the range from 630 A to 1250 A — enabling protection to be matched to the load characteristics, e.g., motors or devices with high inrush current. Instantaneous tripping during a short circuit operates from 2500 A to 15 000 A, ensuring a rapid response to faults. The rated short-circuit breaking capacity at 400 V is 37 kA — a value confirmed in internal data and compliant with IEC/EN 60947-2. Tripping time during a short circuit does not exceed 25 ms at a voltage ≤415 V.

The device does not have a built-in undervoltage release, ground fault protection, or an off-state indicator. Auxiliary contacts are also absent — if status signaling or remote control is required, accessories compatible with the NZM series (e.g., optional motor operator) must be added. Mounting on a TH35 rail or the use of plug-in modules is not possible.

An advantage is compatibility with a wide range of accessories — remote operators, mechanical interlocks, and terminal covers available for the LZM/NZM/LN/N series — facilitating integration with existing installations. The RMS measurement system and "thermal memory" enable more accurate load monitoring without additional sensors.

Operating temperature: from -25°C to +70°C — suitable for industrial and construction conditions. The degree of protection for terminations is IP10 — meaning there is no protection against moisture or dust at the connection points themselves; they must be protected by an appropriate cover or enclosure.