What this 4-pole C-curve 2 A MCB carries
The Siemens 5SY6602-7CC is a 4-pole (3P+N) miniature circuit breaker from the SENTRON 5SY6 series, rated 2 A at 400 V AC with a C tripping characteristic. That C-curve means it holds through moderate inrush — think motorized valves, small contactor coils, or control transformers — and trips fast on a hard short. Breaking capacity is 6 kA per EN 60898, with a parallel 5 kA rating per UL 1077 and CSA C22.2 No.235, so it clears a fault up to that level without welding contacts or cascading to the upstream breaker. Overvoltage category III means it's rated for fixed-installation distribution panels, not just downstream equipment. The 4-pole (3P+N) configuration protects all three phases and switches the neutral, which is standard for TN-S or TN-C-S systems where you need the neutral isolated during a fault.
Terminal capacity and wiring constraints
Both top and bottom terminals accept solid or stranded conductors from 0.75 mm² up to 35 mm² — that's a wide enough range to handle a 6 mm² feed from a subdistribution board or a 25 mm² main tail. The combined terminal design (top and bottom) means you can feed from either direction without swapping the breaker — handy when you're landing a panel with the busbar on top and loads below. The breaker is sealable, halogen-free, and silicon-free — the last two matter if this panel sits in a clean room or near semiconductor fab equipment, where outgassing from PVC or silicone can contaminate optics or wafers. Touch protection is built into the terminals, so a screwdriver slip won't hit live copper.
Environmental limits and mounting flexibility
Storage range is wider at -40 to +75 °C — that's the limit for a spare sitting on a shelf or in a truck. The quick-assembly mounting system is the standard DIN-rail clip — snaps on and off without tools.