SIRIUS safety relay, safety-related standstill monitoring, AC 400 V, 45 mm spring-loaded terminal FK undelayed: 3 NO + 1 NC FK delayed: 0 MK: 3 Auto-start basic unit, max. fault category EN 954-1: 4, maximum achievable PL in accordance with EN 13849-1: e, maximum achievable SIL in accordance with IEC 61508: 3 SIRIUS 3TK28 standstill monitor for safe standstill monitoring of motors. The device can be used flexibly with various motors and frequency converters and has an adjustable standstill delay. It is cost-effective as no additional sensors are required. Fast error diagnostics and display on error LEDs result in higher system availability. The devices are available with different voltages and with screw or spring-loaded connections. Accessories such as labels make handling easier. Safety is a SIRIUS business.