What it is and what it does
The Siemens 5SY6204-7CC is a 2-pole miniature circuit breaker (MCB) from the SENTRON family, carrying a C tripping characteristic and rated at 4 A for AC circuits at 50/60 Hz up to 440 V. Its breaking capacity of 6 kA per EN 60898 means it can safely interrupt short-circuit faults up to that level in residential or light industrial distribution boards. The C-curve (tripping between 5 and 10 times rated current) suits it for loads with moderate inrush — think small motor starters, lighting groups, or control transformers where the start-up spike is higher than a resistive heater but not as aggressive as a heavy motor direct-on-line start.
Mounting and panel fit
Snaps onto standard DIN rail via the quick-assembly system; occupies 2 modular width units (36 mm total). Mounting position is unrestricted — vertical, horizontal, upside-down, whatever the enclosure layout demands. Installation depth is 70 mm behind the panel face, with an overall depth of 76 mm including the front profile. The combined top and bottom terminals accept wiring from either direction, which saves time when daisy-chaining multiple breakers on a busbar.
Environmental and compliance
Rated for ambient temperatures from -40 °C to 75 °C, with a derating curve that drops the continuous current from 4 A at 35 °C to 3.37 A at 55 °C — factor that in if the breaker sits in a hot cabinet next to transformers or drives. Pollution degree 3 (conductive pollution or dry non-conductive that becomes conductive with condensation) and overvoltage category III (fixed installation downstream of the main distribution board) match typical panel environments. IP20 with connected conductors — fine inside a closed enclosure, not for wet or dusty locations. Halogen-free and silicon-free construction, sealable for tamper-evident applications.