JR28 thermal overload relay device (hereinafter referred to as thermal relay) is suitable for overload and phase failure protection of AC motors with AC 50Hz/60Hz, voltage up to 690V, current 0.1-93A for long-term operation or intermittent long-term operation. The thermal relay also has functions such as phase failure protection, temperature compensation, action indication, automatic and manual reset, stop, etc. The performance of this product is stable and reliable. It can be installed in conjunction with contactors or independently. Comply with standards such as GB/T14048.4, GB/T14048.5, and IEC60947-4-1.