Allen-Bradley 140M-C2E-B63 Bulletin 140M Motor Protection Circuit Breaker

Product Description

The 140M-C2E-B63 is a high-performance C-Frame motor protector designed for the comprehensive safeguarding of three-phase motors. This Bulletin 140M device integrates both magnetic and thermal trip mechanisms into a single, compact unit, providing essential protection against short circuits and thermal overloads. The "E" protection class signifies an adjustable thermal trip for precise motor current matching alongside a fixed magnetic trip set at 13 times the rated current ($13 \times I_n$) to handle high inrush currents without nuisance tripping.

Engineered for C-Frame compatibility with a 32A frame rating, the 140M-C2E-B63 (Part Number: 140M-C2E-B63) is rated for a 4 to 6.3 Amp operational range. It offers a normal breaking capacity that reaches up to 100 kA at 415V, making it suitable for demanding industrial power environments. This 3-pole breaker effectively eliminates the need for separate overloads and fuses in many motor starter applications, optimizing panel space and reducing installation complexity.

Technical Specifications

• Manufacturer: Allen-Bradley (Rockwell Automation)

• Model Number: 140M-C2E-B63

• Frame Size: C-Frame (32A rated)

• Adjustment Range: 4.0 to 6.3 Amperes

• Trip Type: Adjustable Thermal / Fixed Magnetic ($13 \times I_n$)

• Breaking Capacity ($I_{cu}$): 100 kA @ 415V AC

• Voltage Rating: 415V AC / 690V AC (Maximum)

• Number of Poles: 3-Pole

• Series: Bulletin 140M

• Mechanical Life: 100,000 Operations

• Mounting: 35mm DIN Rail / Screw Mounting

Application and Selection

This motor protection circuit breaker is primarily utilized in motor control centers (MCC) and localized control panels to protect small to medium motors. It is specifically calibrated for loads requiring a 6.3A maximum ceiling. For optimal performance, the thermal dial should be adjusted to the Full Load Amps (FLA) listed on the motor nameplate.

Engineering FAQ

What does the "Normal Break" rating mean for this unit?

In the 140M series, a "2" designation indicates a standard interrupting capacity suitable for most industrial distribution networks. Despite the "Normal" label, this unit still achieves a high-tier 100 kA breaking capacity at 415V, providing exceptional fault protection.

Can this breaker be used for single-phase motor protection?

While designed as a 3-pole device, it can protect single-phase loads. However, all three poles must be wired in series (looping the signal through all poles) to ensure the internal bimetallic strips heat evenly and prevent premature phase-loss tripping.