What this MCCB delivers for the panel
The Siemens SENTRON 3VA2063-5HN36-0DA0 is a 3-pole molded case circuit breaker (MCCB) rated for 63 A continuous current at 40 °C, built for line protection in distribution panels. Its ETU350 electronic trip unit gives you adjustable overload and short-circuit protection curves — useful when you need to coordinate with downstream breakers rather than rely on a fixed thermal-magnetic response. The 187 kA breaking capacity at 240 V and 121 kA at 415 V means it can sit upstream of a high-fault transformer or busway without worrying about the breaker failing to clear a bolted fault. At 690 V the rating drops to 3.4 kA, so keep that in mind if you're feeding a 690 V motor drive center — that's a coordination-limited zone. Dimensions are 105 mm wide, 181 mm high, 86 mm deep — standard SENTRON 3VA2 footprint for a 3-pole frame, so it swaps into an existing panel bucket without re-drilling the mounting pattern. The undervoltage release (UVR) is built in, which is a common spec for machinery safety circuits that need the breaker to drop out on loss of control voltage.
Current derating and thermal reality
This breaker holds its full 63 A rating up to 50 °C ambient. Above that it starts to taper: 60.6375 A at 55 °C, 58.275 A at 60 °C, 55.9125 A at 65 °C, and 53.55 A at 70 °C. If your panel runs hot — say next to a VFD cabinet or a transformer vault — factor that derating into your load schedule. The maximum power loss is 7.9 W, which is modest for a 63 A electronic-trip MCCB; you won't need forced ventilation for a single unit, but stack several in a row and the cumulative heat matters. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. No trip indicator on the front — you'll know it tripped by the position of the handle or via the auxiliary contacts (which are not included on this variant,).
What the ETU350 trip unit gives you
The ETU350 is an electronic overcurrent release that provides adjustable long-time pickup (Ir), short-time pickup (Isd) with adjustable delay, and instantaneous pickup (Ii). That adjustability is the main reason to pick this over a fixed thermal-magnetic MCCB — you can dial in the coordination with downstream breakers without swapping trip units. The rated insulation voltage is 800 V, so it's fine for 480 V and 600 V class systems with margin. No communication function, no phase failure detection, no ground fault monitoring — this is a straight line-protection breaker, not a power monitoring device. If you need those extras, you'd step up to the 3VA2 with the ETU600 or add external modules.