What this MCCB is and what it does
The Siemens 3VA1220-4EF42-0AE0 is a SENTRON molded case circuit breaker (MCCB) configured for line protection — meaning its primary job is to protect cables and busbars from overloads and short circuits, not motor circuits. It carries a rated continuous current Iu of 200 A and a rated insulation voltage Ui of 800 V, so it is sized for main feeder or large sub-feed duty in low-voltage distribution panels. The overcurrent release is a TM240 thermal-magnetic type — thermal for overload protection, magnetic for short-circuit. No electronic trip unit, no communication module, no undervoltage or shunt release fitted from the factory. This is a straight electromechanical breaker for applications that do not need adjustable trip curves or remote signaling beyond the four HQ auxiliary switches it does carry.
Interrupting capacity — what the voltages mean in practice
This breaker delivers 121 kA at 240 V, 75.6 kA at 415 V, 25 kA at 440 V, and 11.9 kA at 690 V. For a 200 A frame, those are high-interrupting ratings — the 240 V figure covers most North American 120/240 V split-phase or 277/480 V wye secondary faults with headroom, while the 415 V and 440 V numbers suit European and Asian 400 V class systems. The 690 V rating is useful for industrial 600 V class or certain renewable inverter outputs where fault current can be high.
Thermal derating — not a flat 200 A at every ambient
The 200 A rating holds from 40 °C through 50 °C ambient. Above that it derates: 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, and 176 A at 70 °C. If the panel ambient runs hot — say near a transformer or in a poorly ventilated enclosure — use the 60 °C or 65 °C column for sizing. The storage range is -40 °C to 80 °C; operating minimum is -25 °C.
Panel fit and auxiliary contacts
Dimensions: 158 mm high, 140 mm wide, 70 mm deep. The 140 mm width is standard for a 4-pole MCCB in this frame size — verify the mounting hole pattern matches your existing backplate or DIN-rail adapter. The front face carries IP40 protection, so it is protected against tools and wires >1 mm but not against water ingress; keep it inside the enclosure. Four auxiliary switches (HQ type) are built in. These are form-C contacts rated for signaling breaker status (open/closed/tripped) to a PLC or indicator lamp. No additional aux contact block needed unless you require more than four.