What this MCCB is and what it protects
The Siemens SENTRON 3VA1110-4GE42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection — meaning it sits at the incoming feed to a panel or a distribution point, not on a specific motor or load branch. It carries a continuous current Iu of 100 A at 40 °C, and the TM220 thermal-magnetic overcurrent release handles the trip curve: thermal for overloads, magnetic for short-circuit events. The 100% N-conductor protection design means the neutral pole is fully rated, not reduced — important for 4-wire systems where harmonic currents or unbalanced loads can push neutral current up to phase levels.
Breaking capacity — the real-world fault current it can interrupt
This MCCB's interrupting rating varies sharply with system voltage, which is the first thing to check against your available fault current. At 240 V AC it handles 121 kA — a very high figure that covers most industrial service-entrance and large subfeed applications. At 415 V AC it's still substantial at 75.6 kA. At 440 V AC it drops to 52.5 kA, and at 500 V or 690 V AC it's 11.9 kA. The 690 V figure is the one to watch: if your panel feeds a 690 V motor drive or transformer, verify that 11.9 kA exceeds the calculated short-circuit current at that point. The rated insulation voltage Ui is 800 V, so the breaker's internal clearance and creepage are designed for 690 V systems.
Thermal derating — don't assume 100 A at every ambient
The 100 A rating holds flat from 40 °C up to 50 °C — that's the sweet spot for most enclosed panels. At 55 °C it derates to 98 A, at 60 °C to 96 A, at 65 °C to 94 A, and at 70 °C to 91 A. If this breaker lives in a hot electrical room or a sun-exposed enclosure, size the upstream transformer or busway for the derated value, not the nameplate 100 A. The maximum operating temperature is 70 °C; storage range is -40 °C to 80 °C. Power loss at full load is 25 W — not negligible in a sealed enclosure; factor it into your thermal budget.
Physical fit and panel integration
Dimensions are 130 mm high, 101.6 mm wide, 70 mm deep. The 70 mm depth is the body only — add clearance for cable bending radius and the handle throw. IP40 on the front means tools and fingers are kept out, but the breaker is not sealed against water ingress; it belongs in a cabinet, not exposed. No communication module on this variant — it's a standalone thermal-magnetic breaker, not a metering or remote-trip unit. The reference code per IEC 81346-2 is Q, which is standard for switchgear.
Lifecycle and sourcing posture
Lifecycle stage is listed as current — this is an active, in-production part from Siemens. No end-of-life notice or last-time-buy date.