Abb CR309X100B Mechanical Interlock for Contactors

Product Description

The ABB CR309X100B is a mechanical interlock accessory designed to prevent two contactors from engaging simultaneously. This type of interlock is a critical safety component in motor control and power switching applications, ensuring that opposing contactors — such as those used in reversing starters or transfer switch circuits — cannot both close at the same time. Licensed electricians and industrial maintenance technicians install this interlock as part of a properly engineered motor control center or panel assembly. It provides a hard mechanical barrier against simultaneous energization, reducing the risk of phase-to-phase faults.

The CR309X100B is suited for use in commercial and industrial electrical installations where dual-contactor configurations require positive mechanical lockout. Typical applications include forward-reverse motor starters, automatic transfer switching, and multi-speed motor control circuits. The interlock mounts between two compatible ABB contactors and operates without electrical power, making it a purely mechanical safeguard. It is commonly installed in manufacturing facilities, pump stations, HVAC control panels, and similar environments where motor reversing or source transfer is required.

Key Features

• Prevents simultaneous closure of two contactors for hard mechanical lockout protection
• Purely mechanical operation — no auxiliary power required
• Designed for use in reversing starter and transfer switch configurations
• Compact form factor sized to mount directly between paired contactors
• Reduces risk of phase-to-phase fault caused by simultaneous contactor engagement

Compatibility

Designed as an OEM-style mechanical interlock accessory for use with compatible ABB contactor pairs in motor control and power switching assemblies. Consult ABB documentation to verify contactor series compatibility before installation.

Installation Notes

Installation should be performed by a licensed electrician in accordance with NFPA 70 (NEC) and applicable local codes. De-energize and lock out the panel or motor control center completely before servicing or installing this interlock. Verify that both contactors are identical in frame size and confirmed compatible with this interlock kit before assembly. Do not attempt to force or modify the interlock mechanism, as doing so will compromise its safety function.

Technical Specifications

• Weight: 8.02 pounds
• Dimensions (L x W x H): 21 inches x 11.5 inches x 4.5 inches

Standard Information

• Brand: ABB
• Manufacturer Part Number: CR309X100B