What this MCCB is and where it fits
The Siemens SENTRON 3VA2040-6HN42-0AA0 is a 4-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels and motor control centers. It carries a continuous rated current of 40 A across the full ambient range from 40 °C to 70 °C, meaning no derating is needed for elevated panel temperatures up to 70 °C.
Breaking capacity and selectivity
Interrupting capacity reaches 242 kA at 240 V, 187 kA at 415 V, and 121 kA at 500 V. At 690 V it drops to 3 kA, so this breaker is best applied on 480 V or lower systems where fault currents can exceed 100 kA — typical for large transformer secondaries or busway feeds.
Mechanical fit and panel integration
Dimensions are 86 mm deep, 140 mm wide, and 181 mm tall. The 4-pole form factor fits standard Siemens SENTRON mounting bases and busbar systems. Front protection is IP40 — suitable for enclosed panel mounting, not for washdown environments.
Electronic trip unit and monitoring
Fitted with an ETU350 electronic overcurrent release — a microprocessor-based trip unit offering adjustable LSI protection curves (long-time, short-time, instantaneous). No trip indicator, no undervoltage release, no ground-fault monitoring, and no communication function are built in; these are add-on accessories if needed.