Overview
The Allen-Bradley 140MT-C3E-B10 is a motor protection circuit breaker (MPCB) engineered for dependable short-circuit and overload protection in small motor circuits. Built with a C-frame design rated for up to 32 A frame capacity, this breaker combines adjustable thermal and fixed magnetic trip mechanisms for precise protection tailored to low-current motor applications.
Key Features
- Adjustable thermal trip range 0.63–1 A for accurate overload protection on small motors
- Fixed magnetic trip set at 14× rated current for fast short-circuit response
- Class 10 trip performance—trips in 10 seconds or less on overload
- Manual reset with rotary on/off handle and visual trip indication
- C-frame (32 A) compact design for space-efficient panel mounting
- DIN rail mountable with screw terminal connections
- Standard breaking capacity rated for industrial control applications
Technical Specifications
- Ampere Range: 0.63–1 A adjustable thermal
- Magnetic Trip: Fixed at 14× Ie (14 times rated current)
- Trip Class: 10 (Class 10 overload protection)
- Frame Size: C-frame (32 A)
- Voltage Rating: Up to 480 VAC / 690 VAC
- Breaking Capacity: Up to 100 kAIC (standard performance)
- Mounting: 35 mm DIN rail
- Terminal Type: Screw terminals
- Operating Temperature Range: –25°C to +70°C
- Reset Type: Manual
- Poles: 3-pole motor protection
- Series: 140MT (D9N version)
- Dimensions: 55 mm width
Typical Applications
- Small motor branch circuit protection (fractional and ½ HP motors)
- Control circuit protection in industrial automation panels
- Machine tool and CNC equipment motor control
- HVAC compressor and pump motor protection
- Industrial control cabinets and distribution systems
Compatibility & Replacements
The 140MT-C3E-B10 is part of Allen-Bradley’s modular 140MT series motor circuit protectors, designed as a direct replacement for equivalent small-ampere motor protection applications. Higher-ampere variants (e.g., 140MT-C3E-C10 at 6.3–10 A) are available for larger motors. This breaker integrates with three-component starter configurations using Allen-Bradley contactors and overload relays, and is compatible with standard industrial control architectures from Rockwell Automation.
