Motor circuit breaker PKZM4, Ir=2-25A PKZM4-25-EA 190019

Advanced electric motor protection

The PKZM4‑25‑EA motor starter is an advanced protective device from the PKZ series, which has been a synonym for reliable motor protection in the electrical industry since 1932. The Eaton product combines overload and short-circuit protection functions in one compact device, eliminating the need for additional fuse links.

Operating parameters and application capabilities

The device operates within an overload trip setting range of 16‑25 A with a rated continuous current of 25 A. It provides a rated AC-3 operational power of: 12.5 kW at 400V and 5.5 kW at 230V, making it an ideal solution for most industrial applications. The three-phase design (3P) works with voltages up to 690V, and a high rated ultimate short-circuit breaking capacity Icu of 150 kA at 400V AC guarantees effective protection even in the event of severe short circuits.

The thermomagnetic tripping method enables a precise response to different types of faults—instantaneous tripping during short circuits and delayed tripping during overloads. Additionally, the device features phase failure sensitivity, which protects motors from dangerous operating conditions caused by power asymmetry.

Construction and system compatibility

Compact dimensions (140×55×160 mm) and screw terminals ensure a stable and secure connection in applications requiring high reliability. The IP20 protection rating protects against contact with live parts. The device is fully compatible with the Eaton DIL series of contactors, allowing for the creation of complete motor starters without additional intermediate components.

PKZ breakers have been tested for compatibility with IE3 efficiency class motors, where the trip times of the short-circuit releases have been adjusted to the higher inrush currents of these devices. This solution effectively prevents nuisance tripping and guarantees the safe operation of modern drives.

Regulatory compliance and operating conditions

The product meets the requirements of international standards IEC/EN60947, confirming its high quality and operational safety. It can be mounted on DIN rails (top hat rail) in accordance with the IEC/EN60715 standard. Power losses of 14.7 W ensure the energy efficiency of the installation.

The device is available in two versions covering the entire current range from 0.1 A to 63 A, with the entire range requiring only 18 different types. Such versatility significantly simplifies project planning and saves storage space for installers and industrial automation system integrators.