Overview
The Allen-Bradley W75 thermal overload heater is a precision eutectic alloy heater element engineered for reliable motor protection in industrial automation systems. As a Type W heater element, the W75 is part of Rockwell Automation’s legacy 500 Line product family and delivers Class 20 overload protection for general motor control applications. This component is essential for thermal overload relays, magnetic motor starters, and motor control circuits across NEMA-compliant systems.
Key Features
- Current Rating: 79-87 amperes nominal operating range
- Eutectic Alloy Construction: Precision thermal element for accurate, repeatable overload tripping
- Type W Classification: Standard overload relay protection for the 500 Line, providing Class 20 operation and recommended for General Applications
- Bulletin 500 Compatible: Fits Bulletin 500 line starters with Class 20 protection
- Wide Size Range: 62 AMP @ SIZE 2, 82 AMP @ SIZE 3, 89 AMP @ SIZE 4 applications
- New in Box Condition: Factory-sealed, ready for deployment
Technical Specifications
See specification table below.
Typical Applications
- Thermal overload relays, magnetic motor starters and motor controls
- Bulletin 509 starters, 592 overload relays, and similar NEMA-style applications
- General industrial motor protection where Class 20 response time is acceptable
- Multi-phase motor circuits requiring coordinated thermal overload protection
- Equipment retrofit and spare parts replacement for legacy Bulletin 500 systems
Compatibility & Replacements
Compatible With
- Allen-Bradley Bulletin 500 line motor starters
- Allen-Bradley Bulletin 509 starters
- Thermal overload relay models (Bulletin 592 series)
- NEMA Type magnetic motor starters requiring Type W heaters
- Multi-size applications (Size 2, 3, and 4 starters)
Replaces / Drop-In Replacement For
- Previous W75 heater element inventory
- OEM-equivalent thermal heater elements rated 79-87 amperes for Bulletin 500 starters
Works With
- Class 20 overload relay trip curves
- Rockwell Automation Studio 5000 and legacy programming platforms (for system design and selection tables)
- NEMA ICS 2-222 motor starter standards
- Standard 3-phase motor control circuits at 120V, 208V, 240V, 480V, and 600V
