MCCB for line protection — 100 A, 121 kA at 240 V
The Siemens SENTRON 3VA1110-4EF32-0AB0 is a 3-pole molded case circuit breaker (MCCB) rated for 100 A continuous current at 40 °C, with a TM240 thermal-magnetic overcurrent release. Its interrupting capacity at 240 VAC is 121 kA — that means it can safely clear a fault up to that level without upstream cascading, critical for high-fault-current panels close to the transformer. The TM240 release is fixed-trip (no adjustable thermal or magnetic settings), so this breaker is a straight line-protection device — no voltage trigger, no undervoltage release, no ground-fault monitoring. It carries 2 HP-rated auxiliary switches for status feedback to a PLC or annunciator. Rated insulation voltage Ui is 800 V, and the breaker is designed for switching power values in DC networks per the 3VA device manual. IP40 on the front means it's protected against solid objects over 1 mm but not sealed against moisture — standard for indoor panel mounting.
Breaking capacity across voltages — selectivity headroom
At 415 V the breaker is rated 75.6 kA; at 440 V it drops to 52.5 kA; at 690 V it still holds 11.9 kA. These figures matter for selectivity coordination downstream — you can size this breaker as the main in a distribution panel feeding sub-feeders, knowing it will hold through a fault on a branch without nuisance trip.
Thermal derating — runs at 100 A up to 50 °C
The continuous current rating holds flat at 100 A from 40 °C through 50 °C ambient. Above that it derates: 96 A at 55 °C, 94 A at 60 °C, 92 A at 65 °C, 90 A at 70 °C. If your panel ambient runs hot (e.g., near a drive cabinet or in a non-conditioned enclosure), account for the drop — the 70 °C rating is 90 A, not 100.
Panel fit — dimensions and auxiliary contacts
The breaker measures 130 mm high, 76.2 mm wide, 70 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or screw-mounted panel layouts. The 2 HP auxiliary switches are pre-installed; no separate aux kit to order.