The Siemens 3VA2040-4HL42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous current across a 4-pole configuration, using an ETU320 electronic trip unit. It's designed for line protection in distribution panels, sized at 140 mm wide, 181 mm tall, and 86 mm deep — a standard footprint for this frame class.
Breaking capacity and trip curve
Interrupting capacity hits 121 kA at 240 V AC, dropping to 75.6 kA at 415 V and 440 V, then 52.5 kA at 500 V, and 3 kA at 690 V. That 121 kA figure at 240 V means it handles high-fault scenarios common in industrial service-entrance or sub-distribution boards — you're not derating for available fault current on most 240 V feeds. The ETU320 electronic trip allows adjustable long-time, short-time, and instantaneous settings, so you dial in coordination with downstream breakers without swapping trip units.
Thermal derating and environment
Rated 40 A continuously from 40 °C all the way up to 70 °C ambient — no derating needed across that span, which is unusual for a 40 A frame. That means it holds its full rating in a hot panel or near a transformer without recalculating. Operating range is -25 °C to 70 °C; storage from -40 °C to 80 °C.