The Siemens 3VA2040-5KP32-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous current, built on a 3-pole frame that accepts trip units from 60 A up to 480 A.
This breaker's interrupting rating is 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 3 kA at 690 V. Those are the maximum fault currents it can safely clear at each voltage level.
Power loss is 2.2 W maximum at rated current, so heat buildup in a dense panel is negligible.
What the ETU850 trip unit gives you
The ETU850 is an electronic trip unit with a communication function — it can talk to a higher-level system via the breaker's optional communication module (not included, but the interface is built in). It also has an 'other measurement function' capability, meaning it can report load current and event logs if the panel has the right gateway. The trip indicator is not present on this variant (no mechanical flag), so fault indication comes through the electronic interface or a separate auxiliary contact.
Environmental limits and storage
Operating temperature range is -25 °C to +70 °C, with no derating needed across the full span — the 40 A rating holds at every temperature from 40 °C up to 70 °C.