Overview
The Allen-Bradley W46 thermal overload relay heater element is a eutectic alloy thermal protection device engineered for the Bulletin 500 Line of starters and overload relays. Designed to meet NEMA standards, the W46 delivers Class 20 operation and is the industry-standard choice for general motor protection applications. This heater element works by measuring motor current and tripping the circuit when thermal conditions exceed design thresholds, preventing motor burnout and extending equipment life.
Key Features
- Eutectic alloy construction for reliable thermal sensing and predictable tripping curves
- Type W design compatible with Bulletin 500, 509, and 592 overload relay series
- Class 20 protection suitable for general-purpose motor applications
- Precise amperage rating ensures accurate motor current protection
- Drop-in replacement for existing W-series heater elements in legacy and current installations
- Compact form factor compatible with NEMA magnetic starters and motor control enclosures
Technical Specifications
- Rated Current (Size 00–0): 5.46–5.64 A
- Rated Current (Size 1): 5.68–6.51 A
- Heater Type: Eutectic Alloy, Type W
- Trip Class: Class 20
- Application Series: Bulletin 500, 509, 592 Line Starters
- NEMA Compliance: Yes
- Mounting: NEMA-standard overload relay socket
- Weight: 0.05 lbs
Typical Applications
- Motor protection in three-phase AC motor circuits rated 5–6.5 FLA
- Integrated overload trip protection in magnetic motor starters
- Industrial automation control circuits requiring Class 20 thermal protection
- Equipment maintenance and replacement for aging Bulletin 500 starters
- General-purpose motor control in pump, fan, and compressor applications
- OEM and retrofit installations in legacy industrial equipment
Compatibility & Replacements
Compatible With
- Bulletin 500 Line motor starters and overload relays
- Bulletin 509 NEMA magnetic starters
- Bulletin 592 overload relay assemblies
- Three-phase AC induction motors rated 5–6.5 full-load amps
- Standard NEMA motor control enclosures and starter drawouts
Replaces / Drop-In Replacement For
- Legacy W46 heater elements in Bulletin 500 and 509 installations
- Other Type W heater elements where amperage range matches motor requirements
- Verify heater selection using motor nameplate FLA and Rockwell selection tables before ordering to ensure correct trip curve
Works With
- NEMA Class 20 overload relay logic and circuitry
- Three-phase AC power systems (typical industrial 460V, 380V, 230V)
- Eutectic thermal tripping mechanism compatible with all Bulletin 500/509 relay bases
- Ambient temperature compensation per Class 20 specifications
