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SQUARE D Door Mount Operating Mechanism: Door Mount Op Mechanism, 125 A Amps - Square D Circuit Breaker Handles & Operators
SQUARE DSquare D Circuit Breaker Handles & Operators

SQUARE D Door Mount Operating Mechanism: Door Mount Op Mechanism, 125 A Amps

The SQUARE D Door Mount Operating Mechanism (MPN 9421LB7) is a circuit breaker handle and operator accessory designed for use with NEMA 1, 3, 3R, 4, 4X, and 12 enclosures containing PowerPact(R) B Circuit Breakers…

SKU 3G-OTH-19343

Brand
SQUARE D
Item
Door Mount Operating Mechanism: Door Mount Op Mechanism, 125 A Amps
Category
Square D Circuit Breaker Handles & Operators
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Delivery
Worldwide DHL shipping from Singapore; 7–14 business days door-to-door for most destinations.
Payment
Invoicing in USD. Bank transfer (SWIFT) and corporate PO accepted.

Technical Specifications

SQUARE D
Manufacturer Part Number
9421LB7
Amps
125 A
Poles
3
For Use With
NEMA 1, 3, 3R, 4, 4X, 12 Enclosures with PowerPact(R) B Circuit Breakers
Accessory Type
Door Mount Operating Mechanism
Number of Poles
3

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SQUARE D Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The SQUARE D Door Mount Operating Mechanism (MPN 9421LB7) is a circuit breaker handle and operator accessory designed for use with NEMA 1, 3, 3R, 4, 4X, and 12 enclosures containing PowerPact(R) B Circuit Breakers. This 3-pole, 125 A accessory provides a door-mounted operating mechanism for Square D circuit breakers.

Frequently Asked Questions

What is the Square D 9421LB7 door mount operating mechanism used for?

The Square D 9421LB7 is a door-mounted operating mechanism for PowerPact B circuit breakers. It allows external on/off control of a 3-pole, 125 A breaker housed in NEMA 1, 3, 3R, 4, 4X, or 12 enclosures, enabling safe operation without opening the enclosure door.

What are the specifications of the Square D 9421LB7?

The Square D 9421LB7 is a door mount operating mechanism rated for 125 A and 3 poles. It is designed for use with PowerPact B circuit breakers in NEMA 1, 3, 3R, 4, 4X, and 12 enclosures. The accessory type is a door mount operating mechanism, manufactured by Square D.

Where to buy the Square D 9421LB7 worldwide?

3G Electric supplies the Square D 9421LB7 door mount operating mechanism worldwide. As a global industrial distributor, we handle full logistics, customs clearance, and delivery to your site. Contact us for availability and lead time; we source and deliver this Square D accessory globally.

How to install the Square D 9421LB7 door mount operating mechanism?

Install the Square D 9421LB7 by mounting it on the enclosure door per the manufacturer's instructions. Align the mechanism with the PowerPact B breaker handle, secure with provided hardware, and verify smooth operation. Always disconnect power before installation and follow local electrical codes.

Used in

Common applications for SQUARE D
Commercial building electrical panels — Square D QO series plug-in circuit breakers for branch circuit protection
Industrial motor control centers — Square D QOB series bolt-on breakers in NQOD panelboards
Heating equipment installations — Square D QOU series unit-mount breakers for overcurrent protection
Outdoor electrical distribution — Square D L-Frame enclosures housing LAL/LHL breakers for 400 A service
Indoor facility power distribution — Square D Q-Frame enclosures with QBL/QDL breakers for 225 A circuits
Retrofit and replacement in existing Square D load centers — QO series breakers for 120/240V AC systems

SQUARE D Products

3G Electric supplies SQUARE D square d circuit breaker handles & operators. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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