SENTRON 3VA1120-5EF32-0AH0 — 20 A MCCB with TM240 release
The Siemens 3VA1120-5EF32-0AH0 is a SENTRON-series molded case circuit breaker (MCCB) rated for line-protection duty. It carries a continuous current of 20 A at 40 °C and interrupts up to 187 kA at 240 V — that SCCR figure means it clears a bolted fault at that level without rupturing, so it can sit upstream of a distribution panel where the available fault current is high. Three-pole construction with a TM240 thermal-magnetic release. The TM240 designation means the thermal element is fixed at 20 A (the frame rating) and the magnetic pickup is adjustable — typical for feeder or downstream sub-distribution where you need selectivity against branch breakers. Rated insulation voltage is 800 V, so it can be applied on 480 V or 600 V class systems without de-rating the insulation. The interrupting ratings drop as system voltage rises: 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 500 V and 690 V — the 17 kA floor at 690 V still covers most industrial motor-control center fault levels.
Integration and panel fit
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or direct-mount panel layouts. The 70 mm depth leaves clearance for rear-connected busbars or cable ducts behind the breaker. Comes equipped with 2 auxiliary switches plus 1 trip-alarm switch (HQ type), so you get status feedback for PLC or SCADA without adding external relays. The auxiliary contacts share the same mounting space — no extra DIN rail needed. Maximum power loss is 12 W at rated current. That is low enough to avoid forced ventilation in a standard IP54 enclosure, but check the cumulative heat if you pack multiple breakers in a small cabinet.