Allen-Bradley Motor protection circuit-breakers

Motor Protection: Why Allen Bradley “Motor Breakers” Matter

Electric motors are among the most vulnerable assets in a facility. Without proper protection, overloads, short circuits, and phase loss can destroy windings or shortening life drastically. Allen Bradley motor protection circuit breakers provide integrated safeguards—combining thermal-magnetic protection, short-circuit response, and disconnect capability in one compact device. For procurement managers, using Allen Bradley motor breakers (MPCBs) and associated motor protection devices simplifies panel design and ensures reliable motor safeguarding across installations.

Technical Characteristics of Allen Bradley Motor Protection Circuit Breakers

• Device Type: motor protection circuit breakers (MPCB) / motor circuit protectors
• Models / Bulletins: 140MP, 140MT series, and 140M frames supporting motor protection features
• Rated Current Range: typically from 0.1 A up to ~45 A depending on frame (C, D, F
• Trip Mechanism: thermal overload plus magnetic instantaneous trip built in (thermal-magnetic type) 
• Breaking / Interrupting Capacity: high fault current ratings (for example, interrupt rating at 400 V up to 100 kA in some models)
• Frame & Mounting: C, D, F frames with modular mounting for combination units or panel systems
• Phase Loss & Motor-specific Protections: many models detect phase loss, asymmetric currents, and provide motor-friendly trip curves
• Compatibility / Accessories: auxiliary contacts, shunt trips, undervoltage releases, handle operators are supported
• Standards & Certifications: IEC/EN 60947-2, 60947-4-1, UL / cULus, CE marking

Application & Installation Notes

In motor starter panels, Allen Bradley motor breakers typically act as both protection and isolating device. The integrated thermal-magnetic design means you don’t need separate overload relays for many applications. In group installations (multiple motors on same feeder), certain MPCBs can allow tap conductor protection, reducing the need for oversized wiring downstream of the breaker.

For installations downstream of VFDs (variable-frequency drives), specialized MPCB models (e.g. 140MT-D9V) are designed to handle high inrush and harmonics with appropriate trip behavior

Installation tips:

• Ensure correct adjustment of the thermal setting to motor full-load current
• Use proper torque on terminals (follow specs)
• Consider ambient temperature derating for thermal performance
• Coordinate with upstream devices for selectivity—doing time or current-based grading to ensure only the motor’s breaker trips, not the main feeder
• Use proper auxiliary modules for signaling or remote trips

Procurement & Wholesale Considerations

When purchasing Allen Bradley motor protection devices in bulk, procurement professionals typically compare:

• Current / frame match – ensuring motors are protected at correct ranges
• Breaking capacity – must meet fault levels of the installation
• Motor-specific features – phase loss detection, curves tuned for motor loads
• Compatibility with accessories – auxiliary contacts, shunt trip, handle modules
• Special models for VFD downstream or high inrush motors
• Stocking, MOQ, and lead time – maintaining buffer stock due to multiple frame types
• Standardization – using Allen Bradley motor breakers across sites reduces variety
• Certifications & regulatory compliance – ensure devices meet local and international norms

Having multiple motor circuits in one facility all using a unified Allen Bradley MPCB family simplifies spares, training, and maintenance.

Allen Bradley Motor Protection Devices via Bank of Lamps

Bank of Lamps acts as a European wholesale distributor of Allen Bradley motor protection circuit breakers, motor breakers, and associated motor protection equipment. Our stock is held in the Latvia warehouse, enabling timely delivery across UK, Germany, Netherlands, Baltics, France, Spain, Belgium.

We maintain a range of 140MP, 140MT, and 140M frame motor protection devices and accessories (auxiliary contacts, trip units, mounting hardware) to support system integrators, panel builders, and OEMs. For procurement teams seeking consistency, performance, and supply-chain confidence, Allen Bradley motor protection hardware via Bank of Lamps offers a robust foundation for motor safety and circuit protection