Its 125 A rated continuous current Iu 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 — so if your panel ambient runs above 50 °C, size the breaker for the derated figure, not the nameplate. Interrupting capacity varies with line voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V.
Auxiliaries and releases fitted from the factory
The UVR means the breaker trips on loss of control voltage; if your safety circuit expects a shunt trip or you need a separate undervoltage coil, this has it built in. Mechanical endurance is rated at 15 000 cycles — typical for a 125 A frame in distribution duty; not a high-cycling motor-switching MCCB, but fine for infrequent manual or remote switching in a feeder panel.
Panel fit and footprint
Dimensions are 130 mm height, 76.2 mm width, 70 mm depth — a standard 3-pole SENTRON 3VA frame that drops into existing DIN-rail or screw-mount panel layouts without re-drilling.