Overview
The Square D B0.51 is a thermal overload relay heater element designed for use in motor starters and magnetic motor controls. This lot includes five units in used condition, making it a cost-effective solution for replacing or building spare thermal protection sets. The B0.51 thermal unit provides bimetallic strip protection against motor overload conditions, ensuring equipment safety in industrial and commercial electrical systems.
Key Features
- Overload heater element rated 0.37–0.4 Amps for precise thermal protection
- Bimetallic thermal design for reliable trip current accuracy
- Compatible with Square D magnetic starters and overload relay assemblies
- Lot of 5 units—ideal for system replacement or maintenance stockpiling
- Used condition; verify compatibility with your specific motor starter model before ordering
Technical Specifications
| Part Number | B0.51 |
| Manufacturer | Square D (Schneider Electric) |
| Product Type | Overload Relay Thermal Unit / Heater Element |
| Current Rating | 0.37–0.4 Amps |
| Thermal Technology | Bimetallic Strip |
| Quantity per Lot | 5 units |
| Condition | Used |
| Application | Thermal overload relays, magnetic motor starters, motor controls |
Typical Applications
- Three-phase motor protection in NEMA industrial starters
- Single-phase motor control circuits requiring thermal overload detection
- Magnetic contactor assemblies and motor combination starters
- Industrial equipment and plant automation systems
- Maintenance and repair of existing Square D control panels
Compatibility & Replacements
Compatible With
- Square D Class 8536, 8904, 8910, and related magnetic starters
- Square D NEMA and definite-purpose type motor starters
- Thermal overload relay bases accepting Type B thermal units
- Three-phase and single-phase motor control applications at 0.37–0.4 A rating
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator before ordering. The B0.51 may replace other low-amperage thermal units in equivalent Square D starter models; however, exact replacement verification is required based on your specific starter type and motor nameplate data.
Works With
- Square D magnetic starter coils and contact blocks
- Thermal relay bases rated for Type B or equivalent thermal elements
- Motor nameplate full load currents between 0.37–0.4 Amps (consult thermal selection charts)
- Standard 50/60 Hz AC motor control circuits
