WEG UMBW-1B1-25 - MINI CIRCUIT BREAKER UMBW-1B1-25 WEG specifications: UL approval UL1077; Trip curve B; Number of poles 1 pole; Rated current 25 A; Maximum voltage 277 VAC; Type Thermal-magnetic
WEG

UMBW-1B1-25

Alternate Item Number: 14351333

UPC: 7909492435136

Contact for Pricing

Overview

The WEG UMBW-1B1-25 Mini Circuit Breaker (MCB) is a compact, high-performance electrical protection device designed for industrial applications requiring precise overcurrent and short-circuit safeguarding. Engineered by WEG, a globally recognized leader in motor and electrical solutions, this miniature circuit breaker combines thermal and magnetic trip mechanisms to deliver comprehensive protection for branch circuits, distribution panels, and critical industrial systems. The UMBW-1B1-25 is part of WEG's robust portfolio of industrial circuit protection solutions, trusted by engineers and maintenance professionals worldwide for its reliability, durability, and adherence to stringent safety standards. Designed for seamless integration into motor circuits, control panels, and power distribution systems, the WEG UMBW-1B1-25 MCB provides essential protection against overloads and short circuits, preventing costly equipment damage, electrical fires, and system downtime. Its compact form factor makes it ideal for space-constrained installations, while its robust construction ensures long-term performance in harsh industrial environments. The thermal trip mechanism responds to sustained overcurrent conditions, gradually disconnecting the circuit to protect connected loads from heat-related damage. Meanwhile, the magnetic trip offers instantaneous response to short-circuit faults, isolating the fault within milliseconds to minimize risk to personnel and infrastructure. Industries such as manufacturing, oil and gas, mining, water treatment, and renewable energy rely on WEG circuit breakers like the UMBW-1B1-25 to maintain operational continuity and safety. Typical applications include protecting control circuits, lighting systems, motor starters, and branch distribution feeders. The UMBW-1B1-25 is particularly well-suited for use in WEG motor control centers (MCCs), switchgear, and panelboards, where its compatibility with WEG’s ecosystem ensures optimized performance and simplified maintenance. Installation and integration are straightforward, with the UMBW-1B1-25 designed for DIN rail mounting, a standard in industrial electrical systems. Professionals appreciate its user-friendly design, which includes clear markings, easy-to-access terminals, and a snap-in mechanism for quick deployment. WEG’s commitment to quality is evident in the MCB’s compliance with international standards such as IEC 60898-1 and UL 1077, ensuring it meets the rigorous demands of global industrial markets. Choosing the right circuit breaker is critical to system safety and efficiency. The WEG UMBW-1B1-25 stands out for its combination of compact size, rapid response, and robust construction, making it a preferred choice for engineers seeking reliable protection without compromising on performance. Whether deployed in a new installation or as part of an upgrade to existing infrastructure, this MCB delivers the peace of mind that comes with WEG’s decades of expertise in electrical protection and industrial automation. For facilities where uptime and safety are non-negotiable, the UMBW-1B1-25 is a trusted solution that aligns with WEG’s reputation for innovation and reliability.
  • Dual thermal and magnetic trip mechanisms for overload and short-circuit protection
  • Compact DIN rail mounting design for space-efficient installations
  • Compliant with IEC 60898-1 and UL 1077 safety standards
  • Ideal for motor circuits, distribution panels, and industrial power systems
  • Trusted WEG quality for long-term reliability and performance

Specifications

Maximum voltage
277 VAC
Number of poles
1 pole
Rated current
25 A
Trip curve
B
Type
Thermal-magnetic
UL approval
UL1077
Package Weight (Imperial)
0.3 LB
One-hole, metric conductor, standard barrel with window lug, 4-6mm wire, M8 stud hole.

LCMA6-8-C

One-hole, metric conductor, standard barrel with window lug, 4-6mm wire, M8 stud hole.
JB5-2 2 POLE JUMPER 5.2MM SPACING

1SNK905302R0000

JB5-2 2 POLE JUMPER 5.2MM SPACING
JB5-5 5 POLE JUMPER 5.2MM SPACING

1SNK905305R0000

JB5-5 5 POLE JUMPER 5.2MM SPACING
Ground Lug

DNGL

Ground Lug
ZCT,LZR-030(V),EMPR,EXP

76512124011

ZCT,LZR-030(V),EMPR,EXP
INTERLOCK UNIT,AR-12M(SEPERATE),GMC(D)-6~16M

83411621001

INTERLOCK UNIT,AR-12M(SEPERATE),GMC(D)-6~16M

Frequently Asked Questions about WEG

What certifications and standards do WEG products comply with?

WEG products meet extensive international standards across multiple critical categories, including safety, electromagnetic compatibility (EMC), functional safety, and regulatory compliance. Key certifications include UL, cUL, CE, TÜV Rheinland, and compliance with international standards such as EN 61800 series, IEC 61508, ISO 13849-1, and directives like Low Voltage (2014/35/EU), EMC (2014/30/EU), and RoHS. Their products are certified for safe operation in various industrial environments, with specific standards covering electrical safety, thermal performance, electromagnetic immunity, and environmental protection.

What is WEG's warranty policy?

WEG offers an 18-month standard warranty for automation products, covering defects in workmanship and materials. The warranty requires proper transportation, handling, storage, and installation within specified environmental conditions. Repairs must be performed by authorized WEG service, and the warranty is limited to the replacement or repair of the product itself, excluding consequential damages. Extended warranty options are available, including purchasing additional coverage at 2.5% of the product's selling price per year, up to 4 additional years.

What industries and applications are WEG products used for?

WEG products are extensively used across multiple industrial sectors, including packaging equipment, material handling, food processing, pumps, medical/lab equipment, door/gate openers, office machinery, and lawn/garden applications. Their versatile DC motors and variable frequency drives (VFDs) are designed for general industrial use, with solutions ranging from off-the-shelf products to custom OEM designs that meet UL/CSA standards for diverse manufacturing and processing environments.

What technical support does WEG offer?

WEG offers comprehensive technical support through multiple channels, including a dedicated Automation Service Department accessible via toll-free phone (1-877-934-3748) and email ([email protected]). They maintain a global network of accredited service centers worldwide, which customers can locate on their website. Additionally, WEG provides warranty support and technical assistance for their industrial automation products, with pre-approval required for warranty repairs.

What are the key features of WEG products?

WEG products feature advanced industrial automation technologies with key characteristics including high performance, flexibility, and connectivity. Their flagship CFW900 Variable Speed Drive demonstrates core product strengths: intelligent thermal management, built-in safety functions, IoT readiness, advanced energy saving capabilities, and comprehensive communication protocols. WEG drives offer robust performance with features like 150% overload capacity, modern graphic HMI, plug-and-play expansion modules, and compatibility across multiple industrial segments including food and beverage, pulp and paper, and manufacturing.

What communication protocols do WEG products support?

WEG products support multiple industrial communication protocols across their product lines, including EtherNet/IP, Modbus-TCP, Modbus-RTU, CANopen, and optional protocols like Profibus-DP and DeviceNet. Specifically, the PLC500 offers 2x Gigabit Ethernet Ports, 1x CAN Port, and 1x RS485 port, enabling seamless integration with major industrial communication networks.

What environmental ratings do WEG products have?

WEG products feature multiple environmental ratings and protection classes. They offer Protection Class 3C2 as a standard coating and Protection Class 3C3 as an optional extra coating, both compliant with IEC 60721-3-3. Environmental specifications include air relative humidity from 5% to 95% non-condensing, altitude ratings up to 1,000m standard (with current derating above that), and Pollution Degree 2 classification with non-conductive pollution requirements.

What accessories are available for WEG products?

WEG offers a comprehensive range of accessories across multiple product lines. For variable frequency drives like the CFW900, accessories include I/O expansion modules, communication modules, encoder modules, temperature transducer modules, relay output modules, and HMI accessories. These accessories expand communication capabilities, input/output functions, and application flexibility. Most accessories are interchangeable between drive frames and can be installed in backplane slots, with communication network accessories limited to one per variable speed drive.

What are the main product lines offered by WEG?

WEG offers a comprehensive range of industrial automation products, including variable frequency drives (CFW series like CFW100, CFW300, CFW500), soft starters (SSW series including SSW05, SSW07, SSW900), and the innovative Motion Fleet Management (MFM) system for predictive maintenance and asset monitoring. Their product lines are designed to support industrial automation needs across various sectors, providing solutions for motor control, fleet management, and operational efficiency.

How are WEG products typically installed?

WEG products are typically installed with careful attention to mounting specifications, protection ratings, and airflow requirements. For variable speed drives like the CFW900, installation methods include surface mounting, flange mounting, and side-by-side configurations with specific clearance guidelines. Installers must follow precise dimensional requirements for each product frame size, ensuring proper ventilation and electrical connections.