Square D Thermal Overload Relay Heater Element B17.5

The Square D Thermal Overload Relay Heater Element B17.5 is a critical component designed for use in motor starter overload relays to protect electric motors from overheating and potential damage due to prolonged overload conditions. This heater element operates on the principle of bimetallic thermal response, where excessive current causes the element to heat up and trip the relay, interrupting power to the motor. It is compatible with Square D Class 9065 overload relays and is commonly used in industrial applications such as conveyor systems, pumps, and HVAC equipment. Key features include reliable thermal protection, easy installation, and compatibility with NEMA size 00 to 2 starters. Advantages over similar products include Square D's reputation for durability and precise calibration, reducing false trips while ensuring safety. However, it may require periodic replacement in high-duty cycles and is specific to Square D systems, limiting universal compatibility. Based on the provided images, the unit appears to be in used condition with some wear on the box and minor discoloration on the element, but no visible damage. No serial number is evident on the faceplate. Estimated market price for a used unit is around $5-15 USD, depending on condition and availability. For detailed specifications, refer to Square D catalogs or datasheets available on Schneider Electric's website.