Overview
The Allen-Bradley W46 overload relay heater element is a Type W eutectic alloy thermal protection unit designed for Rockwell Automation’s legacy 500 Line motor control systems. This Class 20 heater provides reliable overload protection for NEMA-style starters, contactors, and motor control devices across industrial manufacturing, process control, and mechanical automation applications.
Key Features
- Type W eutectic alloy thermal overload heater for Class 20 operation
- Compatible with Bulletin 500 Line starters and Bulletin 509 NEMA starters
- Precise amperage rating for motors ranging from 5.46 to 6.51 FLA
- Compact, universal heater element design for quick replacement
- Field-proven reliability in legacy motor control circuits
Technical Specifications
- Part Number: W46
- Heater Type: Type W, Eutectic Alloy
- Trip Class: Class 20
- Rated Current (Size 00–0): 5.82 A
- Rated Current (Size 1): 5.68 A
- Bulletin: 500 Line, 509 Starters, 592 Overload Relays
- Operating Principle: Thermal eutectic alloy (temperature-sensitive)
- Weight: 0.05 lbs
- Manufacturer: Rockwell Automation / Allen-Bradley
Typical Applications
The W46 heater is used in:
- Three-phase AC motor starters and contactors
- Machine tool control systems
- Pump and fan motor protection circuits
- Conveyor belt drive systems
- Industrial press and punch automation
- Legacy manufacturing equipment retrofit and maintenance
Compatibility & Replacements
Compatible With
- Bulletin 500 Line motor starters
- Bulletin 509 NEMA starters
- Bulletin 592 overload relays
- Allen-Bradley thermal overload relay sockets and chambers
- NEMA-compliant motor control enclosures
Replaces / Drop-In Replacement For
The W46 is an OEM Rockwell Automation heater element and serves as a direct replacement for worn or tripped W46 units in Bulletin 500 and 509 starters. When selecting a replacement heater, verify your motor’s full-load amperage (FLA) nameplate rating against Rockwell’s W-series selection charts to ensure correct heater selection for proper trip characteristics and ambient temperature compensation.
Works With
- Manual and magnetic NEMA motor starters
- Thermal overload relay chambers and sockets
- AC three-phase motor circuits
- Standard industrial electrical enclosures and control panels
