System-protection MCCB for main-feed or feeder duty
The Siemens SENTRON 3VA4190-4ED34-0AA0 is a 3-pole molded-case circuit breaker rated 90 A at 40 °C with a TM210 thermal-magnetic release providing LI (long-time and instantaneous) protection. The 690 V AC rated operating voltage covers 480 V and 600 V class systems, though the interrupting capacity drops to 25 kA at 480 V and 14 kA at 600 Y/347 V. Panel builders should note the 76.2 mm width (3 in) — it occupies a standard three-pole MCCB slot on the DIN rail or mounting plate, with 129.4 mm height and 75.1 mm depth leaving room for cable bending behind the breaker.
Current derating across the panel ambient range
The breaker is rated 90 A at 40 °C, but the TM210 release must be derated as the panel ambient climbs: 88 A at 45 °C, 86 A at 50 °C, 84 A at 55 °C, 81 A at 60 °C, 79 A at 65 °C, and 77 A at 70 °C. For a panel running at 50 °C — common in a non-air-conditioned electrical room — the usable continuous current is 86 A, not 90 A.