What the ratings mean for fit
The 3VA1110-4EF42-0BH0 is a Siemens 3VA1 IEC frame 160 circuit breaker with a 100 A rated current (In) and a breaking capacity class S rated at 36 kA at 415 V. That 36 kA Icu means it can safely interrupt a fault current up to that level without welding contacts or cascading failure upstream — a key number for panel builders sizing the main breaker in a distribution board. The TM240 thermal-magnetic trip unit gives adjustable overload protection (Ir = 70 A to 100 A) and fixed short-circuit protection (Ii = 5 to 10 x In), so it covers motor and feeder circuits where you need to dial in the exact load current. The built-in undervoltage release (24 V DC) and two auxiliary changeover switches make it a drop-in for safety circuits that need to drop the breaker on loss of control voltage, plus remote status indication.
Deployment context
Mounts on a DIN rail in a standard panel enclosure. The 4-pole configuration with unprotected N conductor suits three-phase four-wire systems where the neutral is not switched. The nut keeper kit simplifies panel assembly by retaining mounting hardware during installation.