What this MCCB is and where it fits
The Siemens 3VA1125-5EF32-0CC0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels and motor control centers. Its 3-pole construction and 25 A rating at 40 °C make it a fit for feeder circuits and branch protection in commercial and industrial switchgear.
Breaking capacity — what the voltage columns tell you
This breaker carries a 187 kA interrupting rating at 240 V AC, dropping to 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at both 500 V and 690 V. The steep roll-off above 440 V means you need to verify the available fault current at your system voltage — at 690 V the 17 kA rating still covers most industrial secondary-distribution scenarios, but it is not a universal high-fault device at that level.
Thermal derating — the continuous current curve
Rated 25 A continuous from 40 °C through 50 °C. At 55 °C it derates to 24 A, holds at 24 A through 60 °C, then steps to 23 A at 65 °C and 70 °C. The flat profile up to 50 °C gives headroom in a warm enclosure; above that the 1–2 A drop is predictable and per the datasheet curve.
Integrated undervoltage release and auxiliary switching
Factory-fitted with an undervoltage release (UVR) and two HQ auxiliary switches. The UVR trips the breaker when control voltage drops below a set threshold — typical for emergency-stop chains or mains-monitoring schemes where loss of control power must open the main contacts. The two auxiliary switches provide status feedback (open/closed) to a PLC or indicator lamp without requiring an external interlock block.
Physical fit and panel integration
Dimensions are 130 mm height, 76.2 mm width, 70 mm depth. The 3-pole width (76.2 mm, or 3 inches) is the standard SENTRON 3VA footprint for this frame size — it occupies three adjacent 25 mm DIN-rail modules if panel-mounted, or bolts directly to a mounting plate. Depth of 70 mm (2.76 in) leaves clearance for rear-access terminals in a typical 200 mm deep enclosure.