Siemens 48ASD3M20 Class 20 Thermal Overload Relay

The Siemens 48ASD3M20 is a three-phase solid-state overload relay (ESP100) designed to protect motors by monitoring current and tripping the circuit when an overload occurs. It is rated for 2.5–10 A full-load current and operates up to 600 V, with a Class 20 trip specification and a manual reset mechanism. This unit uses Frame Size A and is intended for use with Furnas/SIEMENS 48ASD starters in sizes 00, 0 and 1, making it suitable for small-to-medium 3-phase motor control circuits. Common applications include motor protection in compact industrial starter configurations where solid-state overload protection is preferred over thermal relays, and it forms part of the ESP100 family used to retrofit or upgrade existing motor control assemblies.