What this MCCB is and what the ratings mean for your panel
The Siemens 3VA1220-5FF42-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a continuous current rating of 200 A at 40 °C, and holds that full rating through 50 °C — above that it derates linearly to 176 A at 70 °C, so in a hot enclosure you size for the ambient, not the nameplate. The 4-pole configuration handles three-phase plus neutral switching, common in North American and European distribution where a switched neutral is required for full isolation. The TM240 thermal-magnetic release provides fixed thermal protection for overloads and magnetic pickup for short-circuits — no electronic adjustments, which means it's a fit-and-forget part once the continuous current matches your load. Breaking capacity is the headline: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V. At 415 V, that 121 kA SCCR gives you headroom for high-fault installations like transformer secondaries or large motor control centers — you can coordinate downstream without worrying about the main breaker opening on a through-fault. The 70 mm depth, 140 mm width, and 158 mm height fit standard SENTRON 3VA panel footprints. Insulation voltage is rated 800 V, so it's suitable for 690 V systems with margin. Maximum power loss is 42 W — factor that into enclosure thermal calculations if you're packing multiple breakers in a sealed cabinet.
Where it fits in the panel
Mounts in a standard distribution panel on a mounting plate or DIN-rail adapter (the 3VA range uses a common backplate pattern). The 4-pole form factor means it occupies the same width as four single-pole breakers in a row — plan your gland plate and busbar takeoff accordingly. No undervoltage release, no shunt trip, no communication function on this variant — it's a straight thermal-magnetic protector with no auxiliary electronics to wire.