MCCB for high-fault plant floors
The Siemens 3VA2463-7HM42-0AA0 is a SENTRON 3VA2 molded case circuit breaker rated for 630 A uninterrupted current (Iu) at 40 °C, with an ETU330 electronic trip unit handling line protection across four poles. The 330 kA breaking capacity at 240 V means it clears bolted faults on the secondary side of a 2 MVA transformer without the arc flashing upstream — a spec worth checking when the panel feeds motor control centers near furnace zones. Rated insulation voltage Ui is 800 V, giving headroom on 690 V systems where the interrupting rating drops to 9 kA — that 9 kA at 690 V is the hard limit; coordination studies should stay inside it.
Thermal derating and ambient reality
The 630 A base rating holds at 40 °C. At 50 °C it derates to 593 A; at 60 °C to 557 A; at 70 °C to 520 A. If this breaker sits in a non-air-conditioned switchroom near a hot-strip mill, plan for the 70 °C column — 520 A continuous is what the lugs actually carry. Maximum power loss is 162 W. That heat has to leave the enclosure — factor it into the panel cooling budget, especially in a sealed IP54 cabinet.
ETU330 trip unit and N-conductor protection
The ETU330 is an electronic overcurrent release with adjustable N-conductor protection — settable to OFF, 50 %, or 100 % of the phase rating. That matters when the neutral carries harmonic content from VFDs on the same bus. No undervoltage release, no shunt trip (voltage trigger), no communication module — this is a plain line-protection breaker. If the spec calls for remote tripping or load-shedding, the 3VA2 platform accepts plug-in accessories, but this order code ships bare.
Physical fit and panel integration
Dimensions: 248 mm high, 184 mm wide, 110 mm deep. The 184 mm width is the standard 4-pole MCCB footprint for this class — it occupies the same mounting centers as other SENTRON 3VA2 4-pole frames. No rewiring needed if replacing a 5SQ2670-2YA06 or similar 4-pole MCCB on the same bus; the lug centers and phase spacing match the 3VA2 platform. Front protection is IP40 — tools and fingers are kept out, but the enclosure itself must provide the overall IP rating for washdown or dust environments.
Ambient and storage limits
Operating ambient range is -25 °C to 70 °C. Storage range is -40 °C to 80 °C — the storage figure governs long-term spares in unheated warehouses, not running conditions.