WEG MPW-65-3-D065 Motor Protection Circuit Breaker

The WEG MPW-65-3-D065 motor protection circuit breaker covers the 5.0 A to 6.5 A range in the MPW-65 frame, protecting three-phase motors from 3.0 kW to 4.0 kW at 400 V AC. At this motor size range, the MPW-65-3-D065 is frequently specified for HVAC air handling unit supply fans, cooling tower fan motors, wastewater lift pump starters, and light-duty process pump drives in Saudi industrial and commercial facilities. The 3.0–4.0 kW motor range represents a key inflection point in Saudi MCC design, where motor starter assemblies may be combined with soft-start or star-delta arrangements for longer starting cycles.

Technical Performance

The MPW-65-3-D065 delivers Class 10 thermal trip characteristics with phase-loss sensitivity and instantaneous magnetic short-circuit release at approximately 13× Ir. The 150 kA breaking capacity at 400 V AC (subject to specific series) qualifies the device for installation in high-fault-level LV switchboards typically found in main distribution substations of large Saudi industrial complexes. The adjustable dial provides calibration from 5.0 to 6.5 A, covering the full-load current range of 3.0–4.0 kW motors at 380–415 V supply.

Saudi Industrial Standards Compliance

Saudi Aramco's SAES-P-100 specifies motor protection requirements for all motors driven by AC supplies in Saudi Aramco facilities. The MPW-65-3-D065 meets those requirements as an IEC 60947-4-1 type-tested motor protection circuit breaker providing overload and short-circuit protection. SABIC's engineering standards for motor starters (STS series) similarly require IEC-certified MPCBs for motors up to 37 kW, with the MPW-65-3-D065 covering the lower end of this range. Razz Middle East provides Aramco and SABIC-formatted technical submittals and Material Approval Requests (MARs) to support Saudi project procurement processes.

Combination Starter Assemblies

For motors in the 3.0–4.0 kW range with frequent starting or high-inertia loads, WEG recommends combining the MPW-65-3-D065 with a SSW07 or SSW05 soft-starter rather than DOL configuration, reducing starting current and mechanical shock on conveyor and fan systems. Razz Middle East supplies complete combination starters — MPW-65-3-D065 + CWM contactor + SSW soft-starter — factory assembled and tested for Saudi industrial projects.