125 A MCCB with 75.6 kA interrupting capacity
The Siemens SENTRON 3VA1112-3EF36-0CH0 is a 3-pole molded case circuit breaker (MCCB) rated 125 A at 40 °C ambient, designed for line protection in distribution panels and motor control centers. Its interrupting capacity reaches 75.6 kA at 240 V and 52.5 kA at 415 V — figures that cover most industrial fault-current scenarios downstream of a transformer. The 125 A rating holds flat from 40 °C through 50 °C, then derates gradually to 114 A at 70 °C. That thermal curve means the breaker doesn't force a derating penalty in a warm panel until the ambient passes 50 °C — a real advantage for enclosed switchgear. Built-in undervoltage release (UVR) and a supplied basic switch (order code 3VA11123EF360AA0) with two auxiliary switches plus one trip alarm switch (HQ) give this MCCB integrated status feedback and undervoltage protection without external relay wiring.
Panel fit and integration
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth. That 70 mm depth is shallow enough to clear most gland plates and back-panel wiring ducts in standard 600 mm deep enclosures. The 76.2 mm width (3 in) fits a 3-pole MCCB footprint compatible with SENTRON mounting bases. Rated insulation voltage 800 V, maximum power loss 30.6 W. The 30.6 W dissipation is a factor when calculating enclosure thermal rise — at full load this breaker contributes roughly the heat of a small incandescent lamp inside the cabinet. Trip indicator present, no communication function, no ground-fault monitoring version. This is a plain line-protection MCCB — no integrated metering or GFCI module.
Lifecycle and sourcing
Operating temperature range -25 °C to 70 °C; storage range -40 °C to 80 °C. The wide storage range covers unheated warehouses and container transit.