Product Details
Product Overview
The Allen Bradley 140M-K8P-D40 serves as a high-capacity motor protection and power distribution solution within the Bulletin 140M family. This K-Frame Molded Case Circuit Breaker (MCCB) handles heavy-duty loads up to 400 Amps, providing essential instantaneous magnetic trip protection for large-scale industrial motors and branch circuits. While the manufacturer has officially discontinued this series, we provide this unit as 100% Brand New original equipment to ensure your legacy systems maintain peak safety and performance standards.
Technical Specifications
| Feature | Technical Data |
| Manufacturer | Allen Bradley / Rockwell Automation |
| Part Number | 140M-K8P-D40 |
| Condition | 100% Brand New Original |
| Current Rating | 400 Amps |
| Voltage Rating | 480 VAC |
| Phase/Frequency | 3-Pole / 60 Hz |
| Frame Size | K-Frame |
| Horsepower Rating | 90 HP |
| Trip Type | Magnetic (Mag Trip Only) |
| Magnetic Trip Range | 2000 to 4000 Amps |
| Shipping Weight | 8.80 lbs (4.0 kg) |
Engineering Advantages
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Precision Short-Circuit Protection: The integrated magnetic-only trip mechanism monitors current surges instantly. With an adjustable or fixed range between 2000 and 4000 Amps, the breaker interrupts massive faults before they reach downstream equipment, preventing catastrophic motor failure.
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High Power Density: The K-Frame design packs a 400 Amp capacity into a relatively compact 8.80 lb housing. This allows engineers to upgrade power distribution in existing control panels without requiring extensive mechanical modifications or larger enclosures.
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Legacy System Support: As a discontinued component, the 140M-K8P-D40 facilitates direct "drop-in" replacement for failed units. This eliminates the need for expensive system re-engineering or the installation of newer, incompatible frames that would require updated mounting hardware and busbars.
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Optimized for 90 HP Motors: Specifically rated for 90 HP at 480V, this breaker provides the specific inrush current headroom required for large motor startups, preventing nuisance tripping during high-torque acceleration phases.
FAQs
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Since this model is discontinued, is this a refurbished unit?
No. We guarantee this unit is 100% Brand New original stock. It has never been installed or energized. While Rockwell Automation may no longer produce this frame, our supply consists of factory-sealed surplus inventory.
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Can I use the 140M-K8P-D40 as a main disconnect?
Yes. This Molded Case Circuit Breaker functions effectively as a branch circuit protector or a main disconnect for motor control centers, provided the 400 Amp rating and magnetic trip characteristics align with your local electrical code requirements.
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What should I check before installing this K-Frame breaker?
Ensure the lug connections and busbar spacing match the K-Frame footprint. Verify that the magnetic trip range (2000-4000A) appropriately protects your specific motor load based on its Locked Rotor Amps (LRA) to ensure the breaker does not trip during normal startup.
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How does the magnetic-only trip benefit motor circuits?
In motor applications, a separate overload relay typically handles thermal protection. Using a magnetic-only breaker like the 140M-K8P-D40 prevents "double-protection" conflicts, allowing the breaker to focus exclusively on interrupting high-current short circuits.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
Tech & Buying Guide
Understanding Safety Relays in Industrial Automation: Architecture, Operation, and Functional Safety
Standard electromechanical relays provide basic electrical isolation between low-voltage control circuits and high-power output loads. A traditional switching relay features a magnetic coil driving mechanical Common (COM), Normally-Open (NO), and Normally-Closed (NC) contacts. However, standard relays pose severe functional risks when deployed in critical safety interlock circuits. High current inrush or mechanical wear can weld contacts together permanently. If contact welding occurs in an emergency stop circuit, pressing the button fails to halt hazardous machinery movements. Consequently, global functional safety standards prohibit standard relays for critical machine guarding functions.
Mastering Wire Identification in Industrial Automation: The Power of Ferrules and Cross-Ferruling
Proper wire labeling forms the cornerstone of reliable control system installation and long-term maintenance. In complex industrial automation environments, technicians terminate thousands of conductor ends inside control panels, marshalling racks, and field junction boxes. Ferrules serve as individual tube-shaped sleeve markers slipped onto conductors before final termination. While technicians historically relied on pre-printed individual letter rings, modern control panel builders utilize automated ferrule printing machines. These thermal-transfer printers generate durable, single-sleeve heat-shrink tags directly matching approved wiring schematics, significantly accelerating cabinet assembly workflows.
Understanding Marshalling Cabinets in Industrial Automation and Control Systems
Marshalling cabinets serve as the crucial connection hub between field instruments and centralized processing units. In large DCS and PLC control system architectures, hundreds of multipair field cables run from local junction boxes to the central instrument equipment room. The marshalling cabinet houses field terminal blocks, surge arresters, intrinsic safety isolation barriers, and interposing relays. By segregating field field-wiring terminations from sensitive processor hardware, engineers protect expensive controller backplanes from high-voltage transients. Consequently, this modular separation dramatically streamlines maintenance workflows and simplifies system expansion.