Overview
The Furnas 958L109441U is a solid state overload relay engineered for three-phase motor protection. Unlike traditional bimetallic thermal overloads, this solid-state design offers faster, more precise response to overload conditions. The relay provides reliable protection against sustained current overload and phase loss, making it essential for maintaining safe operation of motor-driven equipment in industrial and commercial facilities.
Key Features
- Solid state construction for faster, more accurate overload detection
- Three-phase motor protection with 22–44 ampere rating
- Phase loss sensitivity to detect single-phase conditions
- Compact form factor suitable for integration into motor control centers and starters
- Proven reliability in legacy industrial equipment
Technical Specifications
This unit delivers consistent performance across typical industrial environments. Solid state overloads like the 958L109441U eliminate thermal lag inherent in electromechanical designs, responding instantly to hazardous current conditions. The relay integrates into standard motor control circuits and coordinates with magnetic starters and contactor assemblies.
Typical Applications
- Motor starter and contactor assemblies
- Three-phase motor protection in HVAC systems
- Pump and compressor motor circuits
- Machine tool and industrial equipment protection
- Legacy motor control center retrofits
Compatibility & Replacements
Compatible With
- Furnas Class 8536 and Class 8736 motor starters
- Three-phase AC motor circuits, 230V to 600V rated equipment
- Standard motor control center mounting rails
- Most Furnas contactors and magnetic starters of the era
Replaces / Drop-In Replacement For
The 958L109441U has been superseded by the Furnas 3UB85236EW2 (ESP200 Overload Relay, 10–40A, 3-phase). When planning a replacement, consult your system integrator to confirm mounting compatibility and electrical circuit parameters, as breaker/protection coordination may differ between legacy and modern models.
Works With
- Three-phase AC motor control circuits
- Furnas and Siemens (post-acquisition) magnetic starters
- Standard contactor and starter control schemes
- Motor overload protection coordination with circuit breakers and fuses
