Allen-Bradley 140M-K8P-D40 Motor Protection Circuit Breaker

Configured for adjustable magnetic motor branch protection in Bulletin 140M motor control systems, the Allen-Bradley 140M-K8P-D40 (140M-K8P Motor Protection Circuit Breaker) provides direct electrical interruption for high-current three-phase motor feeders with fixed thermal characteristics and magnetic-only trip execution.

Suffix Breakdown & Model Matrix

The provided documentation identifies the unit as a fixed catalog configuration within the Bulletin 140M series. No manufacturer-defined suffix matrix or configurable ordering breakdown was specified in the source material.

Hardware Specifications

EtherNet/IP and Backplane Integration Characteristics

The Bulletin 140M protection platform is commonly deployed alongside Allen-Bradley motor control assemblies interfaced through deterministic industrial networks including EtherNet/IP architectures. In coordinated motor control panels, the breaker trip state is typically monitored through auxiliary contact assemblies connected to Logix input structures for status acquisition and interlock handling.

The K-frame mechanical construction supports higher feeder density within MCC sections while maintaining clearance spacing for high magnetic trip thresholds. Firmware dependency is not applicable to the breaker itself because trip execution is electromechanical rather than processor-controlled.

Frequently Asked Questions

Q: Does the 140M-K8P-D40 support hot replacement while the motor feeder remains energized?
A: Mechanical replacement should only be performed after upstream isolation and lockout procedures are completed. The breaker is not specified for energized insertion or removal.

Q: Is external control power required for trip operation?
A: No. Magnetic trip execution operates independently from auxiliary control voltage sources. Protective interruption is performed internally by the breaker mechanism.

Q: Can the breaker be mounted directly beside other high-current devices in a control enclosure?
A: Side-by-side mounting depends on enclosure thermal conditions and manufacturer spacing practices. Heat dissipation and conductor bending radius must be verified during panel layout.

Field Installation Guidelines

• Verify conductor torque against terminal labeling before energization.

• Separate motor power conductors from low-level analog or communication wiring inside the enclosure.

• Use copper conductors within the specified terminal wire range and insulation rating.

• Confirm short-circuit coordination with upstream protective devices before commissioning.

• Maintain enclosure grounding continuity between panel backplate, breaker mounting structure, and incoming feeder ground.

• Perform insulation resistance testing on feeder conductors before connecting the motor branch circuit to the breaker terminals.