Siemens 5SY7304-7 Circuit Breaker

Siemens 5SY7304-7 is a 3-pole SENTRON miniature circuit breaker designed to protect three-phase loads in low-voltage distribution systems. Rated for 400 V AC and a nominal current of 4 A, it uses a Type C tripping characteristic and has a breaking capacity of 15 kA, making it suitable for general-purpose short-circuit protection in commercial and light industrial panels. The unit occupies a 70 mm width (D = 70 mm) and accepts conductor cross-sections from 0.75 to 35 mm² with a tightening torque of 2.5–3 Nm. The 5SY7304-7 designation identifies a 3-pole configuration within Siemens’ 5SY7 series, pairing compact, reliable protection with precise current rating for small three-phase circuits. This breaker is commonly used to safeguard three-phase equipment such as lighting panels and small motors, delivering fast, predictable disconnection when overcurrent occurs and enabling selective coordination in multi-breaker installations.