Product Description
The UL-listed Allen-Bradley 140U-K3L3-D40 is a space-saving, cost-effective, 3-pole K-Frame circuit breaker designed to protect industrial control panel applications from thermal overload and short circuits. Supporting back-feeding at 240/480VAC, it's suitable for control, feeder, HACR, and high-intensity-discharge circuits. Rated for 480VAC operation and 400 Amps, it features a 35kA interrupting rating and 750V insulation voltage. Its electronic trip unit, with microprocessor control and long/short time delay, mimics thermal/magnetic breakers, automatically adjusting current carrying capacity and delaying trips until the set value is reached (1.05-1.3x thermal rating). This open-type breaker includes bolt-on screw terminals and operates between -8 and 60 degrees Celsius up to 2000 meters altitude.
Is Your Device Showing These Signs?
The Allen Bradley 140U-K3L3-D40 molded case circuit breaker commonly experiences issues related to nuisance tripping caused by thermal overload or magnetic trip settings being improperly calibrated. Field failures often stem from contact erosion due to repetitive high inrush current loads or short circuit events, necessitating breaker replacement. Another frequent problem involves the operating mechanism failing to latch or unlatch correctly, preventing proper breaker operation and requiring internal component repair or full unit swap. Furthermore, damaged or corroded terminal connections contribute to voltage drops and overheating, demanding terminal cleaning or breaker replacement to ensure proper electrical continuity and prevent fire hazards.
Technical specifications
The Allen-Bradley 140U-K3L3-D40 is a compact and economical 3-pole circuit breaker for industrial control panels, protecting against overloads and short circuits. It supports back-feeding, is rated for 480VAC and 400 Amps, and features a 35kA interrupting rating. Its electronic trip unit with microprocessor control simulates thermal/magnetic breakers, automatically adjusting current capacity and delaying trips. It's an open-type breaker with bolt-on screw terminals, suitable for various circuit types, and operates in a wide temperature range and altitude.
Our Repair Process for the
140U-K3L3-D40
Our repair process for the Allen Bradley 140U-K3L3-D40 molded case circuit breaker begins with a comprehensive evaluation to pinpoint the root cause of the malfunction, whether it is nuisance tripping from thermal overload or magnetic trip setting miscalibration, contact erosion from high inrush current loads or short circuit events, a faulty operating mechanism preventing proper latching, or damaged/corroded terminal connections. Based on the assessment, we either recalibrate the thermal and magnetic trip settings, replace the breaker due to contact erosion or irreparable mechanical failure, repair or replace internal components of the operating mechanism, or meticulously clean/replace terminal connections to eliminate voltage drops and overheating. Each repaired breaker undergoes rigorous testing to confirm adherence to original performance specifications and ensure reliable operation, preventing future failures and maintaining electrical safety.
Your Guarantee: Warranty & Lifetime Support
Your satisfaction is our top priority, and we confidently stand behind the quality of our repairs. That's why every repair service is covered by our comprehensive 24-month warranty. Furthermore, we offer lifetime phone support – if you have questions or need assistance related to our repair down the road, we're here to help. Our service commitment is straightforward: we guarantee our work, and if you're not satisfied, we will make it right. Learn More about our Repair process.
Comprehensive Repairs You Can Depend On
We take immense pride in the quality and reliability of our work. Our process goes beyond simply fixing the immediate problem. We perform a comprehensive inspection of your main board (or other equipment) and proactively replace components known to be failure-prone or showing signs of potential future failure. Before any item is returned, it undergoes rigorous functional testing to ensure it meets performance specifications and operates flawlessly. Visit our main Repair Services page to learn more.
Save Significantly
Our primary goal is to save you hundreds, or even thousands, of dollars compared to the cost of new equipment replacement. By repairing existing components, we provide an economical solution that is also eco-friendly. At Roc Industrial, our commitment to integrity and community drives our consistent growth and ensures you receive a reliable, cost-effective solution.
Please Note: Roc Industrial operates as an independent service provider and is not an authorized distributor for the manufacturers or brands mentioned. Consequently, the original manufacturer's warranty is not applicable to items repaired or sold by us. Roc Industrial provides its own 2-year warranty on all repair services performed.
Buying Options
To receive a quote within 2 hours, please provide us with the details of your requirements. Our team will promptly review your request and send you a custom offer.
Ships from Rochester, NY