Line protection MCCB with TM240 release
The Siemens SENTRON 3VA1120-4EF32-0AF0 is a 3-pole molded case circuit breaker rated for 20 A continuous current (Iu) with a TM240 thermal-magnetic overcurrent release. It is configured for line protection — no undervoltage release, no ground-fault monitoring, no communication module, and no phase-failure detection. The interrupting capacity reaches 121 kA at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V — figures that govern selectivity coordination in a distribution panel. The TM240 release is a fixed thermal-magnetic type — no adjustable thermal or magnetic settings. The thermal element holds 20 A flat from 40 °C through 50 °C, then derates to 19.2 A at 55 °C, 18.8 A at 60 °C, 18.4 A at 65 °C, and 18 A at 70 °C. That derating curve matters when the breaker sits in a warm enclosure alongside other heat sources; the 40 °C to 50 °C plateau gives some headroom before the thermal element starts pulling back. The auxiliary contact configuration is 1 auxiliary switch plus 1 trip alarm switch (HQ type) — useful for remote status indication without needing a separate alarm module. The front face carries IP40 protection, adequate for a panel-mounted breaker behind a closed door. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Panel fit and dimensions
The breaker measures 76.2 mm wide, 130 mm tall, and 70 mm deep — a standard 3-pole MCCB footprint that fits Siemens SENTRON 3VA mounting accessories and busbar systems. The 70 mm depth is the dimension from the mounting surface to the front of the breaker, which governs clearance behind a panel door or inside a distribution board. No rewiring is needed when swapping into a panel originally specified for a 3VA1110-5EE32-0JA0 — the mounting hole pattern, busbar pitch, and terminal layout are identical across the 3VA11xx frame sizes; the difference is in the release type and interrupting rating, not the mechanical envelope.