What this MCCB is and what it does
The Siemens 3VA1180-3EF32-0BH0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection — the job it does is protecting cables and busbars from overloads and short circuits, not motor starting or generator duty. It carries a rated continuous current Iu of 80 A across three poles, with a TM240 thermal-magnetic trip unit that handles the overload curve and instantaneous magnetic pickup. The interrupting ratings are 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V — these numbers tell you the maximum fault current it can safely clear at each voltage level, which is the first check for panel SCCR coordination. The thermal derating curve is flat from 40 °C to 50 °C at a full 80 A, then drops to 76.8 A at 55 °C, 75.2 A at 60 °C, 73.6 A at 65 °C, and 72 A at 70 °C. If your panel ambient runs above 50 °C, you need to account for that reduction in continuous current — the breaker itself will handle the heat, but the load side must be sized for the lower ampacity.
Built-in auxiliary and undervoltage release
This variant ships with an integrated undervoltage release (UVR) and a factory-fitted auxiliary contact block carrying 2 auxiliary switches plus 1 trip alarm switch. The UVR is the coil that drops the breaker when control voltage is lost — standard for safety circuits where a loss of control power must open the main feeder. The auxiliary contacts give you status feedback to a PLC or annunciator panel without adding a separate module. The integrated auxiliary trip order code is 3VA9608-0BB11 — that is the Siemens spare/replacement part number for the auxiliary block if it ever needs swapping. No communication function, no phase failure detection, no ground fault monitoring on this build; it is a straight line-protection MCCB with UVR and aux contacts.
Physical fit and panel integration
The dimensions are 70 mm depth, 76.2 mm width, and 130 mm height. The width is a standard 3-pole MCCB footprint — it fits a 76.2 mm cutout or DIN-rail adapter. Front protection is IP40, meaning it is protected against tools and small wires entering from the front but not against dust ingress; it is intended for installation inside a closed panel, not in a washdown or outdoor location. The reference code per DIN EN 81346-2 is Q — that is the standard designation for switching devices in industrial systems. Storage temperature range is -40 °C to 80 °C; operating temperature range is -25 °C to 70 °C. The mechanical endurance is rated at 15 000 operations — that is the number of open-close cycles the mechanism is designed for before wear becomes a factor.