Overview
The Allen-Bradley W40 thermal overload heater element is a precision-engineered component for industrial motor control and protection. Part of the W Series family, the W40 is designed for use in thermal overload relays, magnetic motor starters, and motor control circuits. This lot includes 5 units, each rated for 3.04 amps maximum, providing Class 20 trip characteristics with manual reset functionality. The eutectic alloy design ensures consistent, reliable performance across NEMA-compliant motor protection systems.
Key Features
- Type W eutectic alloy construction for stable thermal response
- Class 20 trip protection—standard for general industrial motor control
- Rated current: 3.04 amps maximum full load
- Manual reset type with KC standard compliance
- Compatible with Bulletin 500 line starters and NEMA sizes 0 and 1 overload relays
- Lot of 5 units for cost-effective equipment maintenance and spares inventory
Technical Specifications
- Heater element type: Eutectic alloy
- Series: W Series
- Rated current: 3.04A (full load)
- Trip class: Class 20
- Reset type: Manual
- Standard: KC
- Application: Thermal overload relay protection
- NEMA compatibility: Sizes 0 and 1
- Weight per unit: 0.03–0.04 lbs
- Quantity: 5 heater elements
Typical Applications
Allen-Bradley W40 heater elements are widely used in:
- Motor starter and contactor control circuits
- Fractional and small horsepower motor protection
- Industrial machinery with continuous or intermittent duty cycles
- OEM and retrofit motor control panels
- Facilities requiring spare heater element inventory for fast maintenance response
Compatibility & Replacements
Compatible With
- Allen-Bradley Bulletin 500 line starters and overload relays
- NEMA sizes 0 and 1 thermal overload relay bases
- Magnetic motor starters with thermal protection
- Manual reset overload relay circuits (eutectic type)
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator before ordering. The W40 is a standard replacement for equivalent W Series Type W eutectic heater elements in Bulletin 500 motor control circuits.
Works With
- NEMA-standard motor control relay logic
- Thermal overload protection systems
- Class 20 trip-rated motor starters
- Manual reset electromechanical controls
















