Westinghouse Electric M331B Mechanical Interlock

Description:

The Westinghouse M331B Mechanical Interlock is an industrial interlock accessory designed to mechanically prevent simultaneous operation of paired contactors or motor starters in reversing and transfer control applications. Commonly installed in motor control centers, reversing starter assemblies, and industrial automation panels where dependable mechanical interlocking and safe switching operation are required. Maintenance teams, electricians, and system integrators use this interlock assembly for replacement of worn control accessories, starter maintenance, and industrial control system upgrades.

Applications:

The Westinghouse M331B mechanical interlock is commonly used in reversing motor starters, conveyor systems, pumps, compressors, transfer systems, and manufacturing automation equipment where reliable contactor interlocking and prevention of simultaneous contact closure are critical for safe and continuous equipment operation.

Technical Specifications:

• Brand: Westinghouse
• Part Number: M331B
• Alternate Part Number: M33-1B
• Product Type: Mechanical Interlock
• NEMA Size Compatibility: Size 00, 0, and 1
• Application: Industrial motor control systems
• Function: Mechanical contactor interlocking
• Compatible Equipment: A200 and A900 starters and contactors
• Compatible Pole Configurations: 3x3 and 5x5 pole arrangements
• Installation Type: Contactor mounted
• Usage Environment: Commercial and industrial electrical systems
• Designed For: Reversing starters and interlocked control circuits
• Construction: Industrial mechanical interlock assembly
• Electrical Application: Motor control and automation switching systems

Common Replacements:

• Eaton M33-1B
• Cutler-Hammer M331B
• Allen-Bradley 1494V-MI