630 A MCCB with ETU550 — what the ratings mean for your panel
The Siemens SENTRON 3VA2463-5JP32-0KB0 is a 3-pole molded case circuit breaker rated for a continuous current of 630 A at 40 °C, with an ETU550 electronic trip unit configured for line protection. The 630 A figure is the base rating at 40 °C ambient; above that, the breaker derates linearly — 600 A at 45 °C, 570 A at 50 °C, 540 A at 55 °C, 510 A at 60 °C, 480 A at 65 °C, and 450 A at 70 °C. If your panel ambient runs at 50 °C, you're sizing for 570 A continuous, not the catalog 630 A. The ETU550 release gives you adjustable long-time pickup (0.5 to 12 s at tr) and short-time delay (0.5 s max at tsd), so coordination studies actually have something to work with. Breaking capacity varies sharply with system voltage: 187 kA at 240 V, 121 kA at 415 V, 55 kA at 440 V, 36 kA at 500 V, and 9 kA at 690 V. At 415 V — common in industrial distribution — the 121 kA rating covers most transformer-fed fault levels without cascading upstream. The 9 kA at 690 V is a reminder that this is a 600 V class frame; don't spec it for 690 V main feeders expecting full interrupting margin. Rated insulation voltage is 800 V, and the front face carries IP40 protection — fine for a dry indoor panel, but not for washdown zones. The breaker includes a communication function, so it can report status and trip events to a higher-level controller over the SENTRON bus system.
Panel fit — dimensions and mounting
The breaker measures 138 mm wide, 248 mm high, and 110 mm deep. That 138 mm width (5.4 in) is the standard 3-pole SENTRON 3VA frame footprint — it drops into the same panel cutout as other 3VA breakers of this frame size. Depth of 110 mm means it clears most 200 mm deep enclosures with room for rear bus connections. Latching endurance is rated at 15,000 operations, which is typical for a distribution breaker that isn't cycled daily.
Environmental limits and power loss
Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power loss at rated current is 162 W — factor that into your enclosure thermal budget if you're packing multiple breakers in a confined panel.