Schneider Electric B7.70 Thermal Overload Relay Heater Element

Schneider Electric’s Square D B7.70 Thermal Overload Relay Heater Element is a plug-in thermal sensing unit used in motor protection systems to provide calibrated overload protection. It uses a melting alloy/thermal sensing element to trip when current exceeds the preset range, with a typical full-load current range of 4.93–6.27 A and a Class 20 trip rating. The heater mounts as a plug-in unit for overload relay bases and is compatible with Square D Type B and Type S overload relay frames, suitable for industrial motors in MCCs, OEM control panels, conveyors, pumps, compressors, and manufacturing machinery requiring precise overload protection. Application voltage is not directly rated (current-sensing element), and common replacements include Square D B7.71 Thermal Heater Element, Schneider Electric LRD series heater elements, and Siemens 3RU overload heater units.