If your transformer or upstream utility fault current exceeds that, the breaker may fail to clear — so this rating is your first check when coordinating with the service entrance.
Thermal derating and continuous current
Derating starts at 55 °C (96 A), dropping to 90 A at 70 °C.
That's standard for safety circuits where loss of control power must open the load.
The 76.2 mm width is standard for a 3-pole MCCB on DIN rail — it occupies three 25.4 mm module spaces.
Operating environment
That covers most indoor industrial panels, including unheated warehouses or roof-mounted enclosures in temperate climates. The 15 000 mechanical latching cycles are adequate for infrequent switching — this is a line-protection breaker, not a daily disconnect switch.