Overview
The Allen-Bradley W57 is a replacement heating element designed for thermal overload relays in the Bulletin 500 line of motor starters. This eutectic alloy element delivers Class 20 trip protection and is the standard choice for general industrial applications requiring dependable motor overload protection.
Key Features
- Eutectic alloy construction for consistent thermal response
- Class 20 trip classification for general motor control
- Type W element compatible with Bulletin 500 line starters
- Manual reset design for controlled operator intervention
- Compact, drop-in replacement element
Technical Specifications
The Allen-Bradley W57 heating element is engineered to work across multiple motor starter sizes with precise current ratings:
- Current Rating: 15.3–18.5 Amps
- Trip Class: Class 20
- Element Type: Type W, Eutectic Alloy
- Reset Type: Manual
- Line: Bulletin 500 Line Starters
- Size 00–0: 15.7 A Full Load Amps (FLA)
- Size 1: 16.3 A Full Load Amps (FLA)
- Size 2: 16.4 A Full Load Amps (FLA)
- Standard Compliance: NEMA
- Certification: KC standard
Typical Applications
The Allen-Bradley W57 is ideal for protecting 3-phase AC motors in a wide range of industrial environments. Common applications include:
- Magnetic motor starter protection in manufacturing facilities
- Motor control circuits in pump and compressor systems
- General purpose industrial automation equipment
- Replacement in existing Bulletin 500 motor control centers
- Facility maintenance and spare parts inventory
Compatibility & Replacements
Compatible With
- Bulletin 500 line motor starters (all sizes)
- Type W thermal overload relay assemblies
- NEMA-rated motor starter enclosures
- 3-phase AC induction motors
Replaces / Drop-In Replacement For
The Allen-Bradley W57 serves as a direct replacement for OEM heating elements in Bulletin 500 thermal overload relay assemblies. Always verify the specific starter model and size before ordering to ensure proper current rating match.
Works With
- Allen-Bradley Bulletin 500 line motor starter controllers
- Manual and electromechanical motor control systems
- NEMA-compliant facility electrical systems
- Standard 3-phase industrial power distribution
