LS MC-400/MC-500 Heavy-Duty Power Contactor

The LS MC-400/MC-500 Heavy-Duty Power Contactor is a large-frame three-pole or four-pole electromechanical contactor covering 400 A to 500 A AC rated current at 660 V AC, designed for the most demanding industrial motor starting and power distribution switching duties in accordance with IEC 60947-4-1. The MC-400a provides 400 A AC1 (resistive/slightly inductive) and 185 kW at 400 V AC3 (motor switching) continuous service ratings, making it suitable for direct-on-line starting of motors from 90 kW to 185 kW without derating, and for power feeder switching applications up to 400 A. The contactor is available with 24 V DC, 110 V AC, and 230 V AC coil options to match the control circuit voltage of the panel, and auxiliary contact blocks (up to 4NO + 4NC) can be added front-mounted or side-mounted to provide status feedback and interlock signals in motor control circuit applications.

The MC-400 uses a double-break main contact geometry per pole, providing inherently higher contact separation than single-break designs and improving arc interruption performance at high current levels. The contacts are silver cadmium oxide (AgCdO) or silver tin oxide (AgSnO₂) type for superior arc erosion resistance and welding resistance under high-cycling motor starting duties. Mechanical endurance is rated at 10 million operations and electrical endurance at 1 million operations at AC3 duty, equating to approximately 27 years of service at 100 starts per day — reflecting the long service life expected from large motor starters at continuous process facilities in Saudi Arabia. The coil features an energy-efficient AC/DC magnet coil technology that reduces holding power consumption by up to 80% versus conventional AC coils, reducing panel heat load and control circuit power consumption in high-density MCC installations.

Heavy-duty 400-500 A contactors are fundamental components in motor control centres for Saudi Arabia's largest industrial motors — including compressor motors, large pump motors, and fan drive motors at ARAMCO gas compression stations, SWCC desalination pump trains, and NWC main pumping stations. The MC-400/500 is specified in SEC-approved MCC designs for utility substations and industrial switchgear panels across the Kingdom, and meets ARAMCO SAES-P-100 and SEC distribution equipment standards. Saudi panel builders manufacturing SEC-approved motor control centres and switchgear panels regularly use the MC series as the standard contactor for AC3 duty up to 200 kW, benefiting from the wide availability of spare parts and interchangeable auxiliary contact blocks through the LS Electric distributor network.

Razz Middle East maintains local stock of MC-400a and MC-500a contactors with all standard coil voltages (24 V DC, 110 V AC, 230 V AC) for same-week delivery to panel builders and MCC manufacturers across Saudi Arabia. Volume pricing for MCC projects and spare parts contracts is available with annual price agreements for high-volume customers. Our technical team provides coil selection, auxiliary contact configuration, and replacement sizing guidance for existing Telemecanique, Siemens, and ABB contactor replacement projects. All LS MC contactors are supplied with a two-year manufacturer warranty.