63 A MCCB with 187 kA interrupting capacity — what the ratings mean for your panel
The Siemens 3VA1163-5EF36-0AF0 is a SENTRON molded case circuit breaker (MCCB) rated for 63 A continuous current with a TM240 thermal-magnetic trip unit. The headline number here is the interrupting capacity: 187 kA at 240 V AC, dropping to 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V. That 187 kA figure means it can safely clear a fault current up to that level without welding contacts or rupturing the case — critical for high-fault installations like transformer secondaries or large motor control centers where available fault current runs high. The thermal-magnetic TM240 release handles overloads via a bi-metallic element and short circuits via a solenoid. Rated continuous current holds at 63 A through 50 °C ambient; above that it derates stepwise to 56.7 A at 70 °C. That derating curve means you size the breaker for the actual panel ambient, not the nameplate — a 63 A load in a 65 °C enclosure needs the next frame up or active cooling. Three-pole construction, 76.2 mm wide, 130 mm tall, 70 mm deep — standard MCCB footprint for a 3VA frame. The auxiliary contact configuration ships as 1 auxiliary switch plus 1 trip alarm switch (HQ type), which gives you both a status signal and a separate alarm on trip without adding a module.
Integration — panel fit and wiring notes
Mounts on a DIN rail or directly to a backplate via the screw terminals. The 70 mm depth fits standard enclosures with room for wiring gutters. Front IP40 rating means it is protected against tools and wires >1 mm. No undervoltage release, no shunt trip, no communication module, no ground fault monitoring on this variant. If you need remote trip or GF protection, you step up to a different 3VA suffix. The TM240 release is fixed thermal and magnetic — no adjustable long-time or short-time pickup, so coordination studies need to account for the fixed curve.