What this MCCB carries — and where the ratings matter
The Siemens SENTRON 3VA1110-3EF32-0JA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, with a TM240 thermal-magnetic release and an integrated shunt trip (STL) for remote tripping. At 40 °C it carries a full 100 A without derating; the current holds flat through 50 °C, then tapers to 91 A at 70 °C — useful to know if the breaker lives in a warm enclosure near other heat sources. The interrupting capacity at 240 V AC is 75.6 kA, dropping to 52.5 kA at 415 V and 32 kA at 440 V, so this variant is sized for high-fault locations like main switchboards or transformer secondaries where short-circuit current runs high.
Shunt trip and overcurrent release — what the TM240 + STL combination means
The TM240 designation on the overcurrent release means the thermal element is calibrated for a 240 A frame, while the magnetic pickup is fixed and non-adjustable — typical for a thermal-magnetic MCCB where the thermal curve handles overloads and the magnetic element clears short-circuits. The shunt trip (STL) allows a remote signal (e.g., from an emergency stop button, a safety relay, or a PLC digital output) to open the breaker independently of the overcurrent condition. No undervoltage release is fitted, and no ground-fault monitoring module is included, so if either is required downstream, it must be added externally.
Panel fit and ambient limits
The breaker measures 76.2 mm wide, 130 mm tall, and 70 mm deep — a standard 3-pole MCCB footprint that fits SENTRON panelboards and most DIN-rail or screw-mount enclosures. Operating temperature range is -25 °C to 70 °C; storage range extends from -40 °C to 80 °C. Maximum power loss is 25 W, so factor that into enclosure thermal calculations when grouping several breakers in a sealed cabinet. Insulation voltage is rated at 800 V, giving headroom for 480/277 V or 600 V systems without creeping along the limit.