630 A MCCB with ETU550 — interrupting capacity and thermal derating
The Siemens SENTRON 3VA2463-5JP32-0AD0 is a 3-pole molded case circuit breaker rated for 630 A continuous current (Iu) at 40 °C, with an ETU550 electronic overcurrent release. Its interrupting capacity reaches 187 kA at 240 V, 121 kA at 415/440 V, 75.6 kA at 500 V, and 17 kA at 690 V — so at typical 400 V distribution voltages it clears faults up to 121 kA without upstream fuses. Thermal derating is published across the operating range: 630 A at 40 °C, stepping down to 450 A at 70 °C. That means a panel designer sizing for a 55 °C enclosure interior uses the 540 A figure, not the 40 °C nameplate. Maximum power loss is 162 W — relevant for ventilation planning in a sealed cabinet.
Line protection with communication — what the ETU550 adds
This is the line protection version, meaning the trip unit is configured for feeder/cable protection rather than motor or generator protection. The ETU550 release supports communication functions, so it can report status and trip data over the breaker's internal bus — useful for a facility monitoring system or a power-management SCADA layer. The auxiliary contact configuration is 3 auxiliary switches HQ — these are high-quantity signal contacts for remote status indication, not basic open/close flags.
Depth of 110 mm leaves clearance for rear-access wiring and busbar connections in a standard 400 mm deep enclosure.