Overview
The Allen-Bradley W39 Type W thermal overload heater element is a precision-engineered eutectic alloy component designed for motor control and overload protection in industrial applications. Allen-Bradley specifies the W39 as standard overload relay protection for the 500 Line, delivering Class 20 trip classification with consistent performance across Size 00-0 and Size 1 ratings. This lot includes three heater elements for efficient maintenance stocking.
Key Features
- Eutectic alloy construction for stable, repeatable thermal characteristics
- Class 20 protection rating ensures proper overload detection and motor safety
- Compatible with Bulletin 500 Line starters and magnetic motor controls
- Type W thermal overload relay design for consistent trip points
- Manual reset option for controlled restart after thermal events
- Compact design minimizes footprint in starter enclosures
Technical Specifications
- Part Number: W39
- Manufacturer: Allen-Bradley (Rockwell Automation)
- Product Type: Heater Element, Type W
- Material: Eutectic Alloy
- Trip Class: Class 20 Protection
- Full Load Amps (FLA) – Size 00-0: 2.84 A
- Full Load Amps (FLA) – Size 1: 2.86 A
- Reset Type: Manual
- Standard: KC (NEMA)
- Quantity per Lot: 3
- Weight per Unit: 0.04 lbs
- Application: Eutectic overload relay for motor starters
Typical Applications
The W39 heater element is widely used in:
- Three-phase induction motor protection circuits
- Bulletin 500 magnetic motor starters and soft starters
- Industrial machinery with continuous or intermittent duty cycles
- HVAC compressor and pump motor starters
- OEM equipment requiring Class 20 thermal overload protection
- Retrofit and maintenance applications for existing motor control systems
Compatibility & Replacements
Compatible With
- Allen-Bradley Bulletin 500 Line motor starters
- Bulletin 500 magnetic motor controls
- Thermal overload relays with Type W eutectic heater element sockets
- Class 20 protection-rated motor control systems
- NEMA-standard motor starter enclosures
Replaces / Drop-In Replacement For
- OEM Allen-Bradley W39 heater elements in existing Bulletin 500 starters
- Original equipment thermal overload relay components rated for 2.84–2.86 FLA
- Maintenance and spare parts inventory for Rockwell Automation motor controls
Works With
- Rockwell Automation motor control platforms and software suites
- Manual motor starters and automatic restart circuits
- Three-phase AC power distribution systems (50/60 Hz)
- NEMA-rated motor control centers and starter enclosures
- Legacy and modern Bulletin 500 control architectures
