Thermal Derating and Application Context
The 3VA1125-5GD42-0AA0: The 25 A rating holds flat from 40 °C through 50 °C, then derates to 24 A at 55–60 °C and 23 A at 65–70 °C. For a panel seeing 55 °C ambient — common in enclosed switchgear — the breaker is good for 24 A continuous, not the full 25 A.
Breaking Capacity by Voltage Level
The interrupting ratings span a wide voltage range: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at both 500 V and 690 V. For a 480 V panel (common in North American industrial), the relevant figure is the 440 V rating at 75.6 kA — the next step up to 500 V drops sharply to 17 kA, so verify the system voltage against the published curve.
The 101.6 mm width (4 inches) is standard for a 4-pole MCCB in the SENTRON 3VA1 frame — it occupies four 25 mm pole spaces on a DIN rail or panel-mount base. The 70 mm depth leaves clearance for rear-access wiring in a typical 200 mm deep enclosure. An optional motor drive is available as a field-installable accessory.