What this MCCB carries and what it protects
The Siemens SENTRON 3VA1163-3EF32-0JH0 is a 3-pole molded case circuit breaker rated for a continuous current Iu of 63 A at 40 °C, with a rated insulation voltage Ui of 800 V. It is configured for line protection — meaning it sits on the feeder side of a distribution panel, not on a motor branch — and uses a TM240 thermal-magnetic overcurrent release. The TM240 designation means the thermal element is fixed at 63 A and the magnetic short-circuit pickup is set at 240 A (4× Iu), so it handles overloads thermally and clears hard faults magnetically. The interrupting ratings climb to 75.6 kA at 240 V and 52.5 kA at 415 V, which gives selectivity headroom in a main or subfeed position. The breaker includes a shunt trip (STL) for remote opening and comes with 2 auxiliary switches plus 1 trip alarm switch (HQ configuration). There is no undervoltage release, no ground-fault monitoring, no communication module, and no phase-failure detection — it is a straightforward thermal-magnetic MCCB with remote trip capability, sized for a 63 A feeder in a 3-phase system.
Thermal derating and ambient limits
The 63 A rating holds flat from 40 °C up to 50 °C. Above that the thermal curve steps down: 60.48 A at 55 °C, 59.22 A at 60 °C, 57.96 A at 65 °C, and 56.7 A at 70 °C. If the panel ambient runs hot — say next to a drive cabinet or in a non-conditioned enclosure — the actual continuous current must be reduced accordingly. The operating range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Panel fit and auxiliary wiring
The breaker measures 130 mm high, 76.2 mm wide, and 70 mm deep. It mounts on a DIN rail or panel-mount adapter in a standard distribution board. The front face carries an IP40 protection rating — suitable for dry indoor enclosures, not washdown areas. The auxiliary contact block (2 form C aux + 1 alarm) is integrated; the shunt trip coil terminals are accessible on the side. The integrated auxiliary trip order code is 3VA9688-0BL32.