The Siemens 3VA2440-5JP42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 400 A continuous current across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling. Four poles, line-protection design, with an ETU550 electronic trip unit that gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves. This is the breaker you spec for a main feeder or a large motor control center where you need selectivity and coordination downstream.
Interrupting ratings — what they mean for your panel
This MCCB carries a 187 kA interrupting capacity at 240 V — that's enough to clear a fault on a large step-down transformer secondary without the arc flashing over. At 415 V and 440 V it holds 121 kA; at 500 V it's 75.6 kA; at 690 V it drops to 9 kA. The 690 V figure is the one to watch if you're feeding a 690 V drive line — you'll need to verify the available fault current at that voltage doesn't exceed 9 kA, or step up to a higher-rated frame.
Mounting and integration
The breaker measures 184 mm wide, 248 mm high, and 110 mm deep — a standard 4-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures. The ETU550 supports communication (Communication Function: Yes), so you can pull trip data and status over the network without climbing the ladder. No undervoltage release, no ground-fault monitoring module on this variant — if you need those, look at the -5JP42-0AA0's sibling options.