Square D 9421LW7 100A Breaker Operating Mechanism

Product Description

The SQUARE D 9421LW7 is a 100-amp circuit breaker operating mechanism designed for use with PowerPact M and P Frame circuit breakers. The operating mechanism provides the manual actuation interface that allows technicians to open, close, and trip the breaker under load. It mounts to the breaker assembly and translates handle movement into reliable switching action inside the frame. Licensed electricians and industrial maintenance personnel are the primary installers. The unit ships as a single piece and weighs 7.02 pounds, making it manageable for panel work without additional lifting equipment.

This operating mechanism is suited for commercial and industrial electrical distribution applications where PowerPact M or P Frame breakers are installed. These frames are commonly found in motor control centers, switchboards, and panel assemblies handling branch and feeder circuits. The 9421LW7 is a direct accessory replacement, restoring full manual switching function without requiring replacement of the entire breaker frame. It is appropriate for both new installation builds and field service on existing PowerPact assemblies.

Key Features

• Rated for 100-amp circuit breaker operating service
• Compatible accessory for PowerPact M and P Frame circuit breakers
• Provides manual open, close, and trip actuation for the breaker
• Single-unit package simplifies ordering for one-for-one replacement
• Dimensions of 13.2 inches length by 9 inches width by 10.6 inches height accommodate standard frame mounting envelopes

Compatibility

Designed for use with PowerPact M Frame and P Frame circuit breakers as stated by the manufacturer.

Installation Notes

Installation should be performed by a licensed electrician in accordance with applicable NEC requirements and the equipment manufacturer's instructions. De-energize and lock out the circuit and verify the absence of voltage before handling any breaker accessory or operating mechanism. Confirm the breaker frame designation matches M or P Frame before mounting to avoid improper fitment. Do not force the mechanism into position; verify alignment with the breaker actuator before securing the assembly.