Siemens 3RU2126-4AB0 is a three‑pole thermal overload relay for motor protection that mounts to Siemens S0‑size contactors within the 3RU2 family. It provides overload protection for motors in the 11–16 A range, features a Class 10 thermal rating, and uses screw terminals for both the main circuit and the auxiliary circuit. The relay offers manual or automatic reset, enabling restoration of service after an overcurrent event, and is designed for direct mounting on compatible Siemens contactors. This accessory is intended to protect small three‑phase motor circuits in industrial control panels.
