What the breaking capacity ratings mean for your panel
The 3VA2463-5JQ32-0BH0 is a Siemens SENTRON 3-pole molded case circuit breaker rated for 630 A continuous current at 40 °C. The headline number that decides whether it clears a fault without upstream damage is the interrupting capacity: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V. These are the maximum fault currents the breaker can safely interrupt at each voltage level — if your available fault current at the panelboard exceeds the rating at your system voltage, the breaker may not clear the arc, and the upstream device takes the hit. That 187 kA at 240 V is typical for large secondary-side transformer feeds or busway taps where fault current runs high; the drop to 17 kA at 690 V reflects the physics of arc extinction at higher voltage. The ETU560 electronic trip unit handles the overcurrent protection curve. It is a line-protection version — no voltage trigger, no phase failure detection, no ground-fault measurement beyond summation-current formation on the L conductor. The auxiliary contact configuration is 2 auxiliary switches plus 1 trip alarm switch (HQ version), and an undervoltage release (UVR) is fitted. Communication function is present, which means the trip unit can report status and events over a bus, but the exact protocol is not specified in this listing.
Thermal derating — the real continuous current in a warm panel
The 630 A rating is at 40 °C ambient inside the enclosure. At 45 °C it derates to 600 A, at 50 °C to 570 A, at 55 °C to 540 A, at 60 °C to 510 A, at 65 °C to 480 A, and at 70 °C to 450 A. If your panel runs hot — say 55 °C near the top of a sealed cabinet with multiple breakers — the breaker's actual continuous current limit is 540 A, not 630 A. The maximum operating temperature is 70 °C; storage range is -40 °C to 80 °C. Power loss at full rated current is 164.5 W maximum, which contributes to the internal temperature rise and must be factored into the enclosure's thermal budget.
Physical fit and integration
Dimensions are 248 mm height, 138 mm width, 110 mm depth. The width of 138 mm is the standard 3-pole MCCB footprint for this current class — it occupies three 45 mm-wide pole positions in a panel. The 110 mm depth includes the arc chamber and line-side lugs; verify clearance behind the panel door for the trip-unit cover and auxiliary wiring. Latching endurance is rated at 15,000 operations, which covers frequent switching in motor-starting or capacitor-bank duty.