Eaton PKZM4 Motor Protective Circuit Breaker

The Eaton PKZM4 Motor Protective Circuit Breaker extends Eaton's proven PKZ motor protection platform to the higher current range of 40 A to 65 A, addressing medium-sized three-phase motors typically found in the 18.5 kW to 30 kW power range on 400 V AC supply systems. Building on the same architecture as the smaller PKZM0, the PKZM4 retains the integrated short-circuit protection, thermal overload release, and manual rotary switch functionality in a single compact unit, but scales the thermal trip mechanism and contact system to handle the higher continuous currents of medium process pump motors, compressor feeders, and large HVAC fan drives. The device complies with IEC 60947-2 for circuit-breaker applications and IEC 60947-4-1 for motor starter coordination, and achieves a rated short-circuit breaking capacity of up to 100 kA when correctly coordinated with Eaton's recommended upstream fusing — a breaking capacity that is more than sufficient for the fault levels encountered at industrial distribution boards in the Kingdom of Saudi Arabia.

The PKZM4's thermal release is a dual-bimetallic element design calibrated to IEC trip class 10, providing reliable protection against prolonged overloads that heat motor windings without triggering on the higher but brief inrush currents typical of direct-on-line starting of 40–65 A motors. An adjustable current setting dial allows field calibration to within ±5% of the rated motor nameplate current, eliminating the need for a separate adjustable overload relay. Phase-loss sensitivity is built in — if any one phase is lost, the remaining bimetal elements in the other two phases detect the resulting overload within seconds and trip the device, protecting the motor winding from unbalanced heating that is the leading cause of motor burnout at industrial sites. The rotary handle includes a hole for padlock application, meeting LOTO requirements under IEC 60204-1 and Saudi Aramco's electrical safety procedures.

The PKZM4 is widely used in Saudi Arabia for medium-sized industrial motor applications across the oil & gas, petrochemical, water, and power sectors. It is specified for booster pump motor panels at MARAFIQ water and power facilities in Jubail and Yanbu, for cooling compressor feeders at SABIC and SADAF chemical plants, and for large air handling unit fan motor circuits in commercial complexes and hospitals across Riyadh and Jeddah. The 50°C ambient operating temperature rating ensures reliable performance throughout Saudi Arabia's summer months, when switchgear room temperatures in unmaintained plant areas can approach 45°C. Panel builders supplying NEOM, KAPSARC, and Red Sea Project infrastructure regularly specify the PKZM4 for motor feeders where the combined protection and switching functions reduce panel component count and associated wiring labour.

Razz Middle East supplies the PKZM4 series from local in-Kingdom stock, offering 4-hour RFQ response with SAR pricing for all current settings in the 40–65 A range. Our technical team provides coordination studies to verify PKZM4 suitability with upstream MCC busbars and downstream motor cables, ensuring fault-level compliance with the applicable Saudi Aramco SAES or SABIC SES engineering standards. We support installation, commissioning, and warranty claims directly in-Kingdom, covering Riyadh, Jeddah, Dammam, Al Khobar, Jubail, and Yanbu, with no requirement to ship devices internationally for warranty assessment.