What it is and what it does
The Siemens 3VA1110-5EF36-0AB0 is a SENTRON molded case circuit breaker (MCCB) for line protection, meaning it sits at the feeder or main distribution point to protect cables and busbars from overloads and short circuits. Three poles, rated continuous current Iu of 100 A, with a TM240 thermal-magnetic trip unit — the thermal element handles overload timing, the magnetic element clears short-circuit faults fast. Breaking capacity is 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V, so it handles high available fault current on the line side of a panel without needing a current-limiting upstream device.
Thermal derating and real-world current
The 100 A rating holds flat from 40 °C to 50 °C ambient. At 55 °C it derates to 96 A, at 60 °C to 94 A, at 65 °C to 92 A, and at 70 °C to 90 A. If this breaker lives in a hot enclosure — near a drive, transformer, or in a non-ventilated panel — size the load to the derated figure, not the nameplate 100 A. The TM240 release has fixed time delay (tr min and tr max both 1 s), so it's a standard panelboard curve, not adjustable for coordination studies.
Mounting and integration
Width is 76.2 mm, depth 70 mm, height 130 mm — fits a standard 3-pole MCCB footprint on a DIN rail or bolted to a mounting plate. IP40 on the front, so it's fine inside a closed panel but not for washdown or outdoor exposure. Comes with 2 auxiliary switches HP (high-performance) built in, which can be wired to a PLC input for status feedback or to a shunt trip circuit. No undervoltage release, no phase-failure detection, no communication module — this is a basic line-protection breaker, not a smart metering device.