4 A, 4-pole C-curve MCB for panel distribution
The Siemens 5SY6404-7CC is a SENTRON miniature circuit breaker rated 4 A at 400 V AC, 4-pole (4P), with a C tripping characteristic. Breaking capacity is 6 kA per EN 60898 (the standard for household and similar installations) and 5 kA per UL 1077 / CSA C22.2 No.235, so it clears fault currents up to those levels without welding contacts or rupturing the case. That dual rating covers both IEC and North American acceptance — useful for machinery shipped across jurisdictions. Conductor termination accepts solid or stranded wire from 0.75 mm² up to 35 mm², with a screw-terminal torque spec of 2.5 to 3.5 N·m.
Ambient temperature range spans -25 °C to +55 °C operating, with storage from -40 °C to +75 °C; derate humidity per the spec: 95% at 55 °C, 55% at 70 °C, 35% at 75 °C.
Width is 72 mm (4 width units at 18 mm each), height 90 mm, depth 76 mm with an installation depth of 70 mm. Any mounting position is allowed, and the supply cord can enter from any side. Touch protection is built into the terminals. Energy limiting class 3 means it restricts let-through energy during a fault — helps with downstream device coordination and reduces arc-flash stress on cables.