140MT-D9E-B40

Overview of Allen Bradley 140MT-D9E-B40

The Allen Bradley 140MT-D9E-B40 is a motor protection circuit breaker engineered to deliver reliable overload and short-circuit protection for three-phase motor circuits. This D-frame device features an adjustable thermal current range of 2.5 to 4.0 amperes, making it suitable for protecting smaller motor loads in industrial automation environments. The circuit breaker incorporates a fixed magnetic trip set at 14 times the rated current, providing fast protection against short-circuit faults while maintaining Trip Class 10 overload characteristics. Built with high breaking capacity, the 140MT-D9E-B40 supports voltages up to 690V AC and is designed for DIN rail mounting, allowing straightforward integration into control panels and motor control centers. As part of Rockwell Automation's comprehensive motor protection portfolio, this device combines manual motor starting capability with phase loss sensitivity protection, offering a cost-effective solution for non-severe duty motor control applications.

Key Features of Allen Bradley 140MT-D9E-B40

• Adjustable thermal overload protection from 2.5 to 4.0 amperes with Trip Class 10 response
• Fixed magnetic trip at 14x rated current for short-circuit protection
• High breaking capacity rated for voltages up to 690V AC
• DIN rail mounting per EN 60715 standard for easy installation
• Phase loss sensitivity protection for three-phase motor circuits
• IP20 housing protection rating suitable for control panel environments

Technical Specs of 140MT-D9E-B40

• Frame Size: D-Frame
• Current Range: 2.5 to 4.0A adjustable thermal
• Magnetic Trip: Fixed at 14 x Ie (rated current)
• Trip Class: 10A overload protection
• Breaking Capacity: High performance
• Voltage Rating: Up to 690V AC
• Mounting: DIN rail (EN 60715)
• Protection Rating: IP20 housing, IP10 terminals
• Dimensions: 72.1 mm W x 89.2 mm D

Applications / Use Case

The Allen Bradley 140MT-D9E-B40 motor protection circuit breaker is deployed across a wide range of industrial motor control applications where reliable protection is required for fractional horsepower to small integral horsepower motors. Common installations include pump control systems, conveyor drives, fan motors, and process equipment in manufacturing facilities. The device serves as both a disconnect means and protection element, simplifying control panel design while ensuring compliance with IEC 60947-4-1 motor starter standards under utilization category AC-3. Its adjustable thermal range allows precise matching to specific motor full-load current ratings, preventing nuisance tripping while maintaining robust protection against overload conditions. The fixed magnetic trip provides deterministic short-circuit protection, coordinating with upstream protective devices in group motor installation configurations. This circuit breaker is particularly well-suited for single motor branch circuits where manual on/off control is sufficient, eliminating the need for more complex contactor-based starters in non-severe duty applications.

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