Overview
The Allen-Bradley W71 is a Type W eutectic alloy thermal overload heater element engineered for reliable overload protection in industrial motor control systems. With a current rating of 60-66 Amps, this element is designed to integrate seamlessly with Bulletin 500 line starters and operates under Class 20 trip protection standards, making it suitable for general-purpose motor applications requiring dependable thermal protection.
Key Features
- Current rating of 60-66 Amps — covers Size 2, 3, and 4 starter applications
- Eutectic alloy type overload relay element for Bulletin 500 line starters with Class 20 trip rating
- Used for thermal overload relays, magnetic motor starters and motor controls
- Manual reset design — requires manual intervention to re-engage after trip
- Operates across standard ambient temperatures of 40°C (104°F)
- New in box condition — factory sealed and ready for installation
Technical Specifications
This heater element meets NEMA standards and is rated as follows:
- Type: W (Standard for general applications)
- Current Range: 60–66 amps full load
- Trip Class: 20 (Class 20 protection)
- Overload Relay Type: Eutectic alloy
- Reset Type: Manual
- Application: Bulletin 500 line starters
- Motor Service Factor: 1.15 or greater
- Ambient Temperature Rating: 40°C (104°F)
Typical Applications
The W71 heater element is ideal for:
- Three-phase induction motor protection in industrial plants
- General-purpose motor starter circuits requiring standard thermal protection
- Retrofit and replacement installations in existing Bulletin 500 starter systems
- Packaging machinery, conveyor systems, and pump motor control
- Equipment where Class 20 (medium) response time is acceptable
Compatibility & Replacements
Compatible With
- Bulletin 500 line magnetic motor starters
- NEMA-rated thermal overload relays (Type W)
- AC induction motors with service factors 1.15 and above
- General industrial motor control circuits rated for Class 20 protection
Replaces / Drop-In Replacement For
The W71 is a direct replacement heater element within the Bulletin 500 line. Verify compatibility with your existing starter size (Size 2, 3, or 4) and amp rating before ordering. Consult your distributor or system integrator to confirm your exact replacement requirements.
Works With
- Allen-Bradley Bulletin 500 contactors and magnetic starters
- NEMA-compliant overload protection systems
- Manual and semi-automatic motor control installations
