What this MCCB carries and what it clears
The Siemens 3VA2040-7JP42-0AA0 is a 4-pole SENTRON molded case circuit breaker rated for 40 A continuous current with an ETU550 electronic trip unit, designed for line protection in distribution panels. Its interrupting capacity hits 330 kA at 240 V and still delivers 242 kA at 415 V and 440 V, dropping to 187 kA at 500 V and 3 kA at 690 V — the high-end short-circuit ratings mean this breaker can be placed at the service entrance or on a high-fault bus without worrying about cascading failure upstream. The ETU550 electronic release allows adjustable long-time, short-time, instantaneous, and ground-fault protection curves, giving the specifying engineer selectivity coordination options that a thermal-magnetic breaker cannot match.
Thermal derating and panel fit
The breaker holds its full 40 A rating from 40 °C through 70 °C ambient — no derating needed even in a hot enclosed panel. Dimensions are 181 mm high, 140 mm wide, and 86 mm deep, so it occupies a standard 4-pole MCCB footprint on the DIN rail or panel-mount base. Front face carries IP40 protection.
Communication and auxiliary functions
The breaker supports communication functions. It ships without an undervoltage release, without a voltage trigger, and without ground-fault monitoring — those are add-on options if the application requires shunt trip or GF protection. Maximum power loss is 1.2 W at rated load, negligible for panel thermal budgeting.