It is designed for 125 A at 40 °C and delivers an interrupting capacity of 75.6 kA at 240 V AC — sufficient for high-fault branch circuits in industrial distribution panels.
Interrupting and continuous ratings
The interrupting curve drops with system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at both 500 V and 690 V. Continuous current is flat at 125 A from 40 °C through 50 °C, then derates to 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C. For a panel running at 60 °C ambient, the usable rating is 120 A — a 4 % reduction that the panel designer should budget.
Physical fit and auxiliary contacts
The 76.2 mm width (3 in) is standard for a 3-pole MCCB in a SENTRON panelboard — it occupies one 3-pole space.