140M-F8E-C45 — F-Frame Motor Protection Circuit Breaker, 45A, 600V

The 140M-F8E-C45 is an F-frame motor protection circuit breaker with an adjustable thermal current range of 32–45A and a fixed magnetic trip at 13× the set current. Rated for 600V AC and listed as both a manual motor controller and a self-protected (Type E) combination motor controller, it combines disconnecting means, short-circuit protection, and thermal overload protection in a single DIN-rail mounted device — covering the full set of motor branch circuit requirements without a separate fuse or upstream breaker.

Specifications

Parameter	Value
Part Number	140M-F8E-C45
Frame Size	F
Adjustable Thermal Range	32–45 A
Magnetic Trip	Fixed at 13× Ie (set current)
Rated Voltage	600V AC max
Interrupt Capacity	Up to 65 kA at 480Y/277V AC
Poles	3
Mounting	DIN rail or panel mount
Operating Temperature	−25°C to 60°C

One Device, Full Branch Circuit Protection

A conventional motor branch circuit needs three separate functions: a disconnecting means, short-circuit protection, and overload protection. Traditionally that meant a disconnect switch, a set of fuses, and a separate overload relay — three devices to specify, wire, and maintain. The 140M-F8E-C45's Type E self-protected combination motor controller listing covers all three in one unit: the adjustable thermal trip handles overload protection, the fixed magnetic trip clears short-circuit faults instantly, and the manual operating handle provides the lockable disconnect function.

This consolidation simplifies panel design meaningfully at the individual motor circuit level — fewer devices, less wiring, and one component to coordinate rather than three. The Type E listing specifically means no additional upstream short-circuit protective device is required for that individual motor circuit when used within its rated parameters.

FAQ

Q: Does this breaker require a separate fuse for short-circuit protection?

No. As a Type E self-protected combination motor controller, it provides its own short-circuit protection internally — no additional branch circuit fuse is required for the individual motor circuit it serves.

Q: Can the magnetic trip threshold be adjusted?

No. The magnetic trip is fixed at 13 times the thermal setting current — only the thermal overload range (32–45A) is field-adjustable on this model.

Q: Is this breaker suitable for high-inrush motor starting?

The fixed 13× magnetic trip threshold is intended for standard inrush characteristics. For motors with notably high starting current, verify the trip curve against the motor's actual starting profile to avoid nuisance trips on startup.

Q: Can the 140M-F8E-C45 be combined with a separate contactor for remote starting?

Yes. Pairing this breaker with a magnetic contactor forms a Type F combination motor controller, allowing remote (electrically controlled) starting while retaining the breaker's integrated short-circuit and overload protection.

140M-F8E-C45 New Factory Sealed 140MF8EC45 Ser C Starter Contactor