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. The TM210 release is a fixed thermal-magnetic design; no electronic adjustment, so coordination studies should treat the trip curve as fixed. Rated insulation voltage is 800 V, and maximum operational voltage with DC is 600 V. The front face carries IP40 protection — suitable for panel-mount indoor use, not for washdown environments. The 4-pole design with 100% N-conductor protection means the neutral pole is switched and protected equally with the phase poles, which matters for TN-S or TT systems where the neutral must be isolated.
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 187 kA at 240 V covers high-fault service entrance applications on the low side of a step-down transformer.
Physical Fit and Panel Integration
Dimensions are 130 mm height, 101.6 mm width, 70 mm depth. 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.