What it is and what it does
The Siemens 3VA2063-5HL36-0KH0 is a SENTRON molded case circuit breaker (MCCB) with three poles, rated for a continuous current Iu of 63 A. It's built for line protection — meaning it sits on the feeder side, guarding cables and downstream gear against overcurrent and short circuits. The electronic trip unit is an ETU320, which gives you adjustable long-time, short-time, and instantaneous pickup settings — handy for coordinating with downstream breakers so only the faulted branch opens, not the whole panel.
Interrupting capacity — the real story
This breaker's interrupting rating drops as system voltage climbs. At 240 V it's rated for 187 kA — plenty of headroom for most industrial services. At 415 V and 440 V it's still a solid 121 kA. At 500 V you're at 79 kA. But at 690 V it falls to 3.4 kA — that's the number an electrical engineer needs to check against the available fault current at the point of installation. If your transformer can push more than 3.4 kA at 690 V, this isn't the right breaker for that spot.
Thermal derating and panel fit
The breaker carries its full 63 A up to 50 °C ambient. Above that it starts to taper: 60.6 A at 55 °C, 58.3 A at 60 °C, 55.9 A at 65 °C, and 53.6 A at 70 °C. If your panel runs hot — maybe it's near a furnace line or packed tight with other heat sources — you'll need to account for that derating when sizing the load. The dimensions are 105 mm wide, 181 mm tall, and 86 mm deep, so it fits a standard MCCB slot in most distribution panels. Power loss is 5.4 W maximum, which adds to the enclosure heat load.
Auxiliaries and releases
It comes with two auxiliary switches plus a separate trip alarm switch (HQ configuration) — that's three sets of contacts for status feedback to a PLC or annunciator. The shunt trip (STL) allows remote tripping via a control signal, which is standard for emergency-stop circuits or remote shutdown. The integrated auxiliary trip module is order code 3VA9688-0BL33, and the supplied basic switch is 3VA2063-5HL36-0AA0. No undervoltage release, no ground-fault monitoring, no communication module — this is a straightforward line-protection breaker without bells and whistles.