Allen‑Bradley 140U‑K6X3 Bulletin 140U Molded Case Circuit Breaker Frame

Overview

The Allen‑Bradley 140U‑K6X3 is a K‑frame 400A molded case circuit breaker frame from Rockwell Automation Bulletin 140U series. This 140U‑K6X3 is a bare frame unit without trip unit installed, which accepts interchangeable thermal‑magnetic or electronic trip modules for power distribution and motor feeder protection. It is rated 3‑pole, 600VAC, with interrupting rating around 65kA at 480VAC. It is widely used in MCC panels, process skids, pump and fan control, and industrial low‑voltage distribution systems as spare replacement.

Features

The Allen‑Bradley 140U‑K6X3 is a 140U K‑frame MCCB bare frame.140U‑K6X3 supports both thermal‑magnetic and electronic trip units for flexible protection configuration. High interrupting capacity for selective coordination in industrial switchgear. 3‑pole standard arrangement, bolt‑on terminal structure. Modular design; trip unit can be replaced on site without changing the breaker frame. Visible trip indicator for quick fault status identification. Compliant with UL489, CSA C22.2 No.5, IEC 60947‑2 and CE standards.

Specs

Device Type: Molded Case Circuit Breaker Frame Model: Allen‑Bradley 140U‑K6X3 Brand: Allen‑Bradley (Rockwell Automation) Series: Bulletin 140U Frame size: K Frame Frame rated current: 400 A Poles: 3P Rated voltage: 600 VAC Interrupting rating: 65 kA @ 480 VAC Trip unit: Not included, sold separately Certification: UL489, CSA, IEC 60947‑2, CE Status: Legacy spare part

Principle

The Allen‑Bradley 140U‑K6X3 provides the mechanical frame, contact assembly and bus connection for the molded case circuit breaker. Protection logic is implemented by the separately fitted trip unit. When overcurrent or short‑circuit fault occurs, the trip unit triggers the internal mechanism to open the main contacts and isolate the fault circuit.

Applications

The Allen‑Bradley 140U‑K6X3 is deployed in MCC cabinets, power distribution skids, chemical and water treatment automation systems for branch circuit protection. The 140U‑K6X3 is stocked as spare replacement for breaker frame overhaul.