What this 200 A MCCB delivers — and what the ratings actually mean
The Siemens 3VA1220-4FF42-0AA0 is a SENTRON molded case circuit breaker rated for 200 A continuous current at 40 °C, with no derating required up to 50 °C — it holds the full 200 A through that range. Above 50 °C the thermal curve steps down: 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, and 176 A at 70 °C. That means in a warm panel (say 55 °C ambient) you lose 6 A of headroom; plan the load margin accordingly. The TM240 overcurrent release is a thermal-magnetic design — the thermal element handles overloads (long-time protection), the magnetic element handles short-circuits (instantaneous). No electronic trip unit, no communication function, no ground-fault monitoring. This is a straightforward line-protection breaker for distribution panels where you don't need adjustable curves or remote signaling. Breaking capacity varies sharply with system voltage: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, 17 kA at 500 V, and 11.9 kA at 690 V. At 415 V — common in European industrial distribution — the 75.6 kA rating covers most transformer-fed fault levels. At 690 V the 11.9 kA figure is the constraint; verify your available fault current if the breaker lands on a 690 V bus. Four-pole configuration means it switches all three phases plus neutral. The insulation voltage is rated 800 V, so it's suitable for 690 V systems with margin. Maximum power loss is 42 W — negligible for panel thermal calculations but worth noting if you're packing multiple breakers in a sealed enclosure.
Footprint and panel integration
Dimensions are 140 mm wide, 158 mm high, 70 mm deep. That 70 mm depth is the body only — allow additional clearance for cable bending radius and the handle throw. The 140 mm width is a 4-pole frame; a 3-pole sibling would be narrower. No undervoltage release or shunt trip is fitted, so if you need remote tripping you'll add an external module or specify a different variant.