WEG RWB40E-3-A4U008 - OVERLOAD RELAY BU RWB40E-3-A4U008
WEG

RWB40E-3-A4U008

Alternate Item Number: 12786061

UPC: 7909158767878

Contact for Pricing

Overview

The WEG RWB40E-3-A4U008 thermal overload relay is a critical component in industrial motor protection and control systems, designed to safeguard motors from thermal damage caused by sustained overcurrent conditions. As a leading manufacturer in the electrical and automation industry, WEG has engineered this overload relay to deliver precise, reliable protection tailored to the demands of modern industrial applications. Unlike generic circuit breakers that prioritize wiring protection, the RWB40E-3-A4U008 is specifically calibrated to protect motors from burnout by monitoring current levels and tripping the circuit when overload conditions persist beyond safe thresholds. This thermal overload relay is part of WEG's RWB40E series, a trusted line of protection devices known for their durability, accuracy, and ease of integration into motor control centers (MCCs), starters, and other industrial control panels. The primary function of the RWB40E-3-A4U008 is to prevent motor damage by disconnecting the power supply when the motor draws excessive current for an extended period. This is achieved through a thermal sensing element that reacts to heat generated by overcurrent, ensuring that the motor is protected from both short-term overloads and prolonged thermal stress. The relay's adjustable trip settings allow technicians to precisely match the protection level to the motor's full load amperage (FLA), providing flexibility across a wide range of motor sizes and applications. This adjustability is particularly valuable in industries where motors operate under varying load conditions, such as manufacturing, mining, water treatment, and HVAC systems. One of the standout features of the RWB40E-3-A4U008 is its compatibility with WEG's extensive lineup of motor control products, including contactors and motor starters. This seamless integration ensures optimal performance and reduces the complexity of system design and maintenance. The relay is designed for use in environments where reliability and uptime are critical, featuring robust construction and compliance with international standards for industrial electrical equipment. Its compact form factor and DIN rail mounting capability make it an ideal choice for space-constrained control panels, while its user-friendly interface simplifies installation and adjustment. Industries that rely on continuous motor operation—such as oil and gas, pulp and paper, food and beverage, and renewable energy—benefit significantly from the protection offered by the RWB40E-3-A4U008. In these sectors, motor failure can lead to costly downtime, production losses, and safety hazards. By deploying this overload relay, facilities can mitigate these risks, extend motor lifespan, and reduce maintenance costs. The relay's thermal protection mechanism is particularly effective in applications where motors are exposed to harsh conditions, such as high ambient temperatures, dust, or moisture, as it responds directly to the heat generated by the motor windings. Selecting the right overload relay involves considering factors such as motor type, load characteristics, and environmental conditions. The RWB40E-3-A4U008 addresses these needs with its class 10 trip curve, which is suitable for most general-purpose motors, as well as its ability to handle a wide current range. Installation is straightforward, typically involving connection to the motor starter's auxiliary contacts and wiring to the control circuit. WEG provides comprehensive documentation and support to assist engineers and technicians in configuring and maintaining the relay, ensuring long-term reliability. WEG's reputation as a global leader in electrical engineering and automation solutions further enhances the value of the RWB40E-3-A4U008. With decades of experience in developing industrial motor protection solutions, WEG is trusted by engineers and facility managers worldwide for its innovation, quality, and adherence to stringent safety standards. The RWB40E-3-A4U008 exemplifies this commitment, offering a balance of performance, durability, and ease of use that makes it a preferred choice for protecting critical motor assets in diverse industrial settings.
  • Thermal overload protection for industrial motors to prevent burnout
  • Adjustable trip settings for precise motor current protection
  • Class 10 trip curve for compatibility with general-purpose motors
  • Compact DIN rail mounting for space-efficient control panels
  • Seamless integration with WEG motor control and starter systems

Specifications

Package Weight (Imperial)
0.55 LB
Combine high performance with compact dimensions: - 1000 V AC / DC IEC 600 V UL, - Opt for the best marking visibility thanks to the up-front, flat marker zone, which lets you mark up to eight digits or increase the font size.

1SNK705010R0000

Combine high performance with compact dimensions: - 1000 V AC / DC IEC 600 V UL, - Opt for the best marking visibility thanks to the up-front, flat marker zone, which lets you mark up to eight digits or increase the font size.
HPS Open Style Control Transformer, 150VA 240x480V-120x240V 50/60Hz

C2G0150MQMJ

HPS Open Style Control Transformer, 150VA 240x480V-120x240V 50/60Hz
Power supply for DIN-rail

PS-60

Power supply for DIN-rail
BK63H 1P B2A 10kA 120/240VAC UL1077

0626030563

BK63H 1P B2A 10kA 120/240VAC UL1077
ACS380 AC Drive, 3-380-480V In, 3HP, 6A, Type OPEN, 1.5 overload, Integrated, HxWxD 6.69x2.76x7.52 in, Module

ACS380-040S-07A2-4

ACS380 AC Drive, 3-380-480V In, 3HP, 6A, Type OPEN, 1.5 overload, Integrated, HxWxD 6.69x2.76x7.52 in, Module
C.BREAKER TMAX XT2N 125 UL/CSA FIXED THREE-POLE WITH FRONT TERMINALS AND THERMOMAGNETIC RELEASE TMA R 90 I3=450...900 A

XT2NU3090BFF000XXX

C.BREAKER TMAX XT2N 125 UL/CSA FIXED THREE-POLE WITH FRONT TERMINALS AND THERMOMAGNETIC RELEASE TMA R 90 I3=450...900 A
Pushbuttons. 104P heavy duty Oiltight Pushbutton. Nameplate. XN1B PR.No. CR100699

CR104PXN1B

Pushbuttons. 104P heavy duty Oiltight Pushbutton. Nameplate. XN1B PR.No. CR100699
MC-50a AC120V 50/60Hz SCREW 1a1b (Metasol) EXP (MC50A-30-11-K7-S-E)

1338006700

MC-50a AC120V 50/60Hz SCREW 1a1b (Metasol) EXP (MC50A-30-11-K7-S-E)
N3 SCREW COVER - 10X10X6 - GRA

C3SC10106GY

N3 SCREW COVER - 10X10X6 - GRA
The NNC75X75WH2 Halogen-Free Wide Slot Wiring Duct is used to route, protect, and manage wires near sensitive electronic equipment and in environments where heat resistance or public safety is a concern. UL 94 flame class of V-0 with a UL recognized continuous-use temperature up to 95 C (203 F). Halogen-Free, Polyphenylene Oxide (PPO). Mounting holes provided. 2.85" x 2.97" (72.4 mm x 75.4 mm) and 6.6' (2 m) long. Cover included. Color White. 5 pieces per package.

NNC75X75WH2

The NNC75X75WH2 Halogen-Free Wide Slot Wiring Duct is used to route, protect, and manage wires near sensitive electronic equipment and in environments where heat resistance or public safety is a concern. UL 94 flame class of V-0 with a UL recognized continuous-use temperature up to 95 C (203 F). Halogen-Free, Polyphenylene Oxide (PPO). Mounting holes provided. 2.85" x 2.97" (72.4 mm x 75.4 mm) and 6.6' (2 m) long. Cover included. Color White. 5 pieces per package.
DS9 RECEPTACLE POLY BLUE SIZE 5 IP 66/67/69 3P+G 150 A 480 VAC 60 Hz

3194213000K04

DS9 RECEPTACLE POLY BLUE SIZE 5 IP 66/67/69 3P+G 150 A 480 VAC 60 Hz
General Electric Control Products. Nema Power Devices. Ol Relay 610F8364

CR324E610F

General Electric Control Products. Nema Power Devices. Ol Relay 610F8364

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.