Square D 9421LD7 Circuit Breaker Operating Mechanism 400A

Product Description

The SQUARE D 9421LD7 is a circuit breaker operating mechanism designed as an accessory for 400-amp circuit breakers. The operating mechanism provides the manual or motorized actuation interface that allows the breaker to be opened and closed during normal operation or service. Licensed electricians and qualified electrical contractors install this type of component during panel service, switchgear maintenance, or breaker replacement work. The unit measures 12.5 inches in length, 8.5 inches in width, and 8.5 inches in height, and weighs 3.68 pounds.

This operating mechanism is intended for use in commercial and industrial electrical distribution applications where 400A circuit breakers require an external or replacement actuating mechanism. It is suited for installation in switchboards, panelboards, or switchgear enclosures where the original operating mechanism has failed or must be replaced during a system upgrade or repair.

Key Features

• Designed for use with 400A circuit breakers
• Provides the actuation interface for breaker open and close operations
• Compact form factor: 12.5 x 8.5 x 8.5 inches
• Lightweight at 3.68 pounds for ease of handling during installation
• OEM-style replacement for straightforward fitment

Compatibility

Designed for use with 400A circuit breakers as specified by SQUARE D. Confirm exact breaker model compatibility against SQUARE D documentation before ordering.

Installation Notes

Installation should be performed by a licensed electrician in accordance with NEC requirements and the authority having jurisdiction. De-energize and lock out the circuit and verify absence of voltage before beginning any work on the breaker or its operating mechanism. Follow SQUARE D installation instructions for proper alignment and attachment of the mechanism to the breaker frame. Do not attempt to install or service this component while the breaker is energized.