Overview
The Allen-Bradley W66 is a eutectic alloy thermal overload heater element engineered for motor control and overload protection in industrial applications. The W66 heater element is compatible with Allen-Bradley 500 Line overload relays and is rated for a full load current range of 35.5 to 43 amps. It features Class 20 trip timing, making it suitable for general purpose motor protection. This is a standard W-type heater designed to be a drop-in replacement in existing 500 Line starter and contactor assemblies.
Key Features
- Used for thermal overload relays, magnetic motor starters and motor controls
- Designed for manual reset operation and is intended for use in standard industrial environments
- Type W heater elements for the 500 Line provide Class 20 operation and is recommended for General Applications
- Eutectic alloy construction for reliable thermal response
- Compact, standard mounting compatible with Bulletin 100/500/609/1200 line starters
Technical Specifications
- Full Load Current Range: 35.5–43 Amps
- Trip Class: Class 20 (trip time ≤20 seconds at 600% of rating)
- Heater Type: W Series, Eutectic Alloy
- Reset Type: Manual
- Mounting: Standard for 500 Line Starters
- Weight: 0.05 lbs
- Applicable for Sizes: 1, 2, 3, 4 (depending on full load amp requirement)
- Standards: CCC, KC
- Manufacturer: Allen-Bradley (Rockwell Automation)
Typical Applications
This heater element provides reliable protection for motors by monitoring current and triggering a trip when overload conditions occur. The W66 is commonly used in:
- General-purpose industrial motor circuits
- Packaged motor starters and controllers
- Equipment requiring standard thermal overload protection
- Squirrel-cage AC induction motors rated 460V, 380V, and 230V
Compatibility & Replacements
Compatible With
- Allen-Bradley 500 Line Overload Relays (Bulletin 500)
- Bulletin 100, 609, 1200 Line Starters
- Type W Series thermal overload relay assemblies
- Magnetic motor starters with W-type heater sockets
- Size 1, 2, 3, and 4 motor starter frames
Replaces / Drop-In Replacement For
The W66 is a standard heater element replacement for any existing 500 Line thermal overload relay requiring a 35.5–43A rated heater. Verify compatibility with your system integrator before ordering to ensure correct size and frame match for your specific starter or contactor.
Works With
- 500 Line thermal overload relay assemblies
- Magnetic motor starter contactors
- Motor control center (MCC) buckets
- Combination starters and soft-starters (with manual bypass)
