Siemens 3UA5400-1J Relay

Siemens 3UA5400-1J is a 3‑pole, thermal‑delayed overload relay designed to protect 3‑phase motor circuits and integrate with Siemens motor starters. Frame‑mounted for quick mounting onto a compatible contactor, this device provides a current sensing range of 6.3 to 10 A and includes an auxiliary contact configuration of 1 normally open and 1 normally closed (1NO+1NC) for interlock or control signaling. As part of Siemens’ 3UA family, the relay protects connected motors by interrupting current when overheating or overload conditions are detected, helping prevent motor damage and enabling safer, more reliable operation within automated systems. Typical applications include general‑purpose 3‑phase drives such as conveyors, pumps, and fans where compact, integrated motor protection is desired in a starter configuration. The 3UA5400‑1J catalog designation identifies a dedicated overload relay within Siemens’ legacy 3UA protection line, intended to accompany compatible contactors and accessories to form a complete motor protection circuit in industrial control panels.