MCCB for line protection — 200 A frame, TM220 release
The Siemens SENTRON 3VM1220-3EE32-0AA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a TM220 thermal-magnetic overcurrent release, meaning the thermal element handles overloads and the magnetic element handles short-circuits — no electronic trip unit, no communication function, no ground-fault monitoring. Rated operating voltage is 690 V AC, with an insulation voltage of 800 V. The continuous current rating holds at 200 A from 40 °C through 50 °C, then derates linearly to 176 A at 70 °C. That means in a 50 °C panel ambient — common in enclosed switchgear — you still get the full 200 A; above that, the thermal curve governs the actual ampacity. The interrupting ratings are 76 kA at 240 V AC, 53 kA at 415 V AC, 32 kA at 440 V AC, and 12 kA at 500 V AC. For a 415 V distribution board, the 53 kA figure gives solid headroom against most utility fault levels. Maximum power loss is 42 W — relevant for thermal coordination inside a sealed enclosure. Front protection is IP40, so tools or fingers won't contact live parts, but the body is not sealed against moisture ingress. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Physical fit and panel integration
Dimensions are 105 mm wide, 158 mm high, 70 mm deep. The 105 mm width is the standard 3-pole MCCB footprint for this frame size — it occupies three 35 mm DIN-rail module spaces if mounted on a DIN rail, or bolts directly into a panel via the rear mounting points. No undervoltage release, no voltage trigger, no trip indicator on this variant; the TM220 release is self-powered and requires no auxiliary supply.