The Siemens SENTRON 3VA1112-1AA36-0JC0 is a 3-pole switch disconnector in MCCB design, rated for 125 A continuous current (Iu) and up to 690 V AC / 500 V DC operational voltage. It is built on the 160 A frame and ships with a shunt trip release (STL) for 110–127 V DC/AC, plus two HQ auxiliary switches. The front-terminal clamp connection suits panel wiring where the disconnector is the isolation point rather than a protective device.
What the ratings mean for fit
At 125 A continuous and 690 V AC, this switch disconnector handles motor loads, transformer primaries, or distribution feeders within its frame rating. The absence of overload or short-circuit protection means it is intended as a load-break isolator — upstream protection (a fuse or MCCB) must cover fault interruption. The shunt trip allows remote emergency-off or undervoltage tripping; it operates on 110–127 V DC or AC 50/60 Hz, so verify control voltage matches the coil rating. The 2 HQ auxiliary contacts (form C) provide status feedback to a PLC or indication lamp. Dimensions are 70 mm deep, 76.2 mm wide, 130 mm tall — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures. IP40 on the front means the operator face is protected against tools and small wires; the enclosure itself should provide the overall IP rating for the installation environment. Operating temperature range of -25 °C to +70 °C and storage from -40 °C to +80 °C cover most indoor industrial panels. Maximum power loss of 38 W at full load should be factored into enclosure thermal calculations, especially in sealed cabinets.