63 A MCCB with ETU320 — what the ratings mean for panel fit
The Siemens 3VA2163-6HL36-0KA0 is a 3-pole SENTRON molded case circuit breaker rated for 63 A continuous current at 40 °C ambient, with an ETU320 electronic trip unit that provides adjustable overload and short-circuit protection curves. The 242 kA breaking capacity at 240 V means it can safely interrupt fault currents up to that level without upstream cascading — critical for high-fault installations like transformer secondaries or large motor control centers. The integrated shunt trip release (STL) allows remote tripping via a control signal, which is useful for emergency-stop circuits or supervisory shutdown sequences.
Breaking capacity across voltage — selectivity planning
The 3VA2163-6HL36-0KA0 delivers 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 5 kA at 690 V. For selectivity studies, the 187 kA at 415 V is the figure to coordinate with upstream devices — it exceeds typical utility fault levels at that voltage, so you can often use a smaller upstream breaker without sacrificing coordination. The 5 kA at 690 V is the limiting case; verify the available fault current at that voltage before specifying.
Panel dimensions and thermal derating
At 86 mm depth, 105 mm width, and 181 mm height, this MCCB fits standard panel-mount cutouts for 3-pole SENTRON frames. The 63 A rating holds steady from 40 °C through 50 °C, then derates linearly to 53.55 A at 70 °C — a 15% reduction at the upper operating limit. For enclosed panels with limited airflow, use the 55 °C or 60 °C column (60.6 A and 58.3 A respectively) for conservative sizing. Maximum power loss is 4 W, which is negligible for thermal budget calculations.
Trip unit and release configuration
The ETU320 overcurrent release is a basic electronic trip unit with fixed time-current curves — no communication, no ground-fault monitoring, and no phase-failure detection. The shunt trip release (STL) is the only auxiliary release; there is no undervoltage release, no auxiliary contact, and no voltage trigger. If your application requires remote status feedback or undervoltage protection, you will need to add external relays or select a variant with those options. The basic switch assembly is order code 3VA2163-6HL36-0AA0, and the integrated auxiliary trip is 3VA9688-0BL33 — useful for spare-parts planning.
Environmental range and storage
Operating temperature spans -25 °C to 70 °C, with storage from -40 °C to 80 °C. The storage limit governs handling and warehousing, not running conditions. For outdoor enclosures in cold climates, the -25 °C lower operating bound is adequate for most regions; verify if sustained sub-25 °C ambient is expected.