630 A MCCB with ETU350 — what the ratings mean for your panel
The Siemens 3VA2463-5HN32-0DL0 is a SENTRON 3VA2 molded case circuit breaker (MCCB) in the line protection version, carrying a continuous current rating of 630 A at 40 °C. That 630 A figure is the thermal base — the breaker holds that current indefinitely without tripping at a 40 °C ambient. For higher ambient temperatures inside a crowded enclosure, the rated current derates stepwise: 612 A at 45 °C, 593 A at 50 °C, 575 A at 55 °C, 557 A at 60 °C, 538 A at 65 °C, and 520 A at 70 °C. If your panel ambient runs above 40 °C, size the breaker against the derated value, not the catalog headline. The ETU350 electronic trip unit handles the protection curve — adjustable long-time, short-time, instantaneous, and ground-fault (though this variant ships without ground-fault monitoring). The breaker is 3-pole, rated insulation voltage 800 V, and carries a maximum power loss of 164.5 W. That power loss matters for enclosure thermal calculations: at full load the breaker dissipates heat equivalent to a small resistive heater, so verify your cabinet's ventilation or derating factor.
Breaking capacity across system voltages
This MCCB's interrupting capacity varies sharply with system voltage — a key selection parameter for fault-current studies. At 240 V it interrupts 187 kA; at 415 V and 440 V, 121 kA; at 500 V, 75.6 kA; and at 690 V, 9 kA. The 690 V figure drops to 9 kA, so if your installation runs a 690 V distribution, confirm the available fault current stays under that limit. The 187 kA at 240 V is among the highest in the 3VA2 frame class, suited for high-capacity transformer secondaries or large motor control centers.
Auxiliary and undervoltage release configuration
The breaker ships with a factory-installed auxiliary contact block: 2 auxiliary switches (form C) plus 1 trip alarm switch and 1 electrical alarm switch (HQ type). That gives you remote status — open/closed, tripped on fault, and a separate electrical alarm contact for annunciation. An undervoltage release (UVR) is also fitted, which trips the breaker when control voltage drops below a set threshold — common for emergency-stop circuits or undervoltage protection schemes. The UVR design is specified as an undervoltage release. No communication function is included on this variant.
Mounting dimensions and panel fit
Physical footprint: width 138 mm, height 248 mm, depth 110 mm. The 3VA2 frame is designed for screw-mounting on a backplate or mounting plate inside a distribution panel or MCC bucket. The 110 mm depth includes the case body but not the handle throw — allow clearance for the toggle arc and any auxiliary wiring. The 138 mm width means it occupies roughly 5.4 inches of horizontal space per pole; plan your busbar and lug landing zones accordingly.