Line protection MCCB with ETU350 trip unit
The Siemens SENTRON 3VA2063-6HN32-0AG0 is a 3-pole molded case circuit breaker rated for line protection, carrying 63 A continuous current (Iu) with an ETU350 electronic overcurrent release. The 242 kA breaking capacity at 240 VAC (187 kA at 415/440 V, 121 kA at 500 V, 4 kA at 690 V) means it can safely interrupt fault currents up to those levels without upstream cascading — critical for high-fault installations like transformer secondaries or large motor control centers. The ETU350 provides adjustable long-time, short-time, instantaneous, and ground-fault protection curves, giving selectivity coordination flexibility that a thermal-magnetic breaker cannot match.
Thermal derating and panel integration
The breaker holds full 63 A rating through 50 °C ambient; above that it derates linearly to 53.55 A at 70 °C (the maximum operating temperature). Mounting dimensions are 105 mm wide × 181 mm high × 86 mm deep — this is a standard SENTRON 3VA2 frame size that drops onto a DIN rail or panel-mount baseplate. The front face carries IP40 protection (tools and wires >1 mm kept out), adequate for enclosed panel installations. Power dissipation is 5.4 W maximum at rated load, so ventilation requirements are modest.
Auxiliary contacts and release configuration
This variant ships with one auxiliary switch plus one trip alarm switch (HP type) integrated. There is no undervoltage release, no shunt trip (voltage trigger), no ground-fault monitoring module, and no communication function — it is a pure line-protection breaker with remote status indication via the auxiliary contacts. The latching endurance is rated at 20,000 operations, which suits frequent switching applications like capacitor bank or motor feeder duty.