Overview
The Allen-Bradley W51 thermal overload heater is a Type W heater element engineered for NEMA-compliant motor protection circuits. This compact, precision-manufactured component provides Class 20 thermal overload protection and is recommended for general-purpose industrial applications where reliable motor circuit protection is essential.
Key Features
- NEMA-rated thermal overload heater element for eutectic-type overload relays
- Class 20 operation suitable for general-purpose motor applications
- Rated 8.95–9.32 amps nominal current
- Manual reset type for controlled motor starter operation
- Drop-in replacement element compatible with bulletin 100/500/609/1200 line starters
- KC standard compliance for North American applications
Technical Specifications
- Current Rating: 8.95–9.32 amps
- Type: Type W heater element
- Trip Class: Class 20
- Reset Type: Manual
- Overload Relay Type: Eutectic
- Standard: KC (NEMA)
- Mounting: Eutectic overload relay socket
- Weight: 0.04 lb
- UPC: 781180154263
Typical Applications
The W51 heater element is widely used in:
- Magnetic motor starters and soft starters for general industrial machinery
- Three-phase and single-phase motor protection circuits in NEMA-compliant control cabinets
- OEM equipment manufacturers requiring drop-in thermal overload protection
- Retrofit and repair applications for existing motor control systems
- Conveyor, pump, fan, and compressor motor circuits requiring Class 20 protection
Compatibility & Replacements
Compatible With
- Bulletin 100 line magnetic motor starters
- Bulletin 500 line motor starters
- Bulletin 609 motor control equipment
- Bulletin 1200 line starters
- Eutectic-type thermal overload relays in NEMA motor control circuits
- Standard NEMA-rated motor starter enclosures
Replaces / Drop-In Replacement For
The W51 is a direct replacement for equivalent Class 20 Type W thermal overload heater elements in existing motor starter installations. Verify compatibility with your system integrator or equipment documentation before ordering to ensure proper amperage rating match.
Works With
- Allen-Bradley motor control products (all bulletin 100/500/609/1200 series)
- Rockwell Automation industrial control systems
- Standard NEMA motor starter contactor coils and overload relay assemblies
- Three-phase and single-phase motor protection schemes
- Manual and magnetic motor starter circuits
