Siemens SFH21 Thermal Overload Relay Heater Element

Siemens SFH21 Thermal Overload Relay Heater Element is a replacement heating element for the SFH-series thermal overload relays used to protect motors in control panels. This SFH21 element is specified to draw 1.48 to 1.62 amps, matching the current range of the SFH21 module and providing the heat input required for the SFH overload mechanism. Designed for installation inside compatible SFH-series overload relays, it is intended for motor protection circuits in which a contactor or motor starter is used. As a genuine Siemens replacement part, it allows maintenance teams to restore the protective function of the SFH21 without replacing the entire relay assembly. Typical applications include protection of small- to mid-size AC motors in conveyors, pumps, fans, and machine tools in industrial settings, where reliable thermal protection is needed to prevent motor overheating and equipment damage.