Integrator's note on the 3VA1112-6EF36-0CC0
The Siemens 3VA1112-6EF36-0CC0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current Iu of 125 A and a rated insulation voltage Ui of 800 V. Three poles, no trip indicator, no voltage trigger — this is a straight thermal-magnetic breaker with the TM240 overcurrent release. The interrupting capacity at 240 V hits 220 kA, which gives serious headroom for high-fault panels; at 415 V it still holds 154 kA, and at 440 V it's 75.6 kA. At 690 V it drops to 17 kA — still useful for secondary distribution in 690 V systems but not for primary fault duty at that voltage.
Ratings and what they mean for panel fit
The 125 A rating holds flat from 40 °C through 50 °C, then derates to 120 A at 55 °C, 117.5 A at 60 °C, 115 A at 65 °C, and 112.5 A at 70 °C. If your panel ambient runs above 50 °C, you lose about 10 % of the continuous rating — factor that into the load calculation. The 15 000 mechanical endurance cycles (latching) tell you this breaker is built for occasional switching, not daily motor-start duty. The undervoltage release (UVR) is included — it will trip the breaker on loss of control voltage, which is standard for safety disconnects or emergency-stop chains. No communication function, no phase failure detection, no ground fault monitoring — this is a basic protection-only device, no bells.
Panel integration and physical fit
Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep. IP40 on the front — fine for a dry indoor panel, not for washdown or outdoor exposure. The auxiliary contact version is 2 auxiliary switches HQ (high-quality), which give two form-C contacts for status feedback. The integrated auxiliary trip is a separate order code (3VA9608-0BB24) — if you need a shunt trip or UVR as a field-installed accessory, that's the part number to add. No communication module, so no Modbus or PROFIBUS integration; this breaker is a standalone protection device.