What this MCCB is and where it fits
The Siemens SENTRON 3VA1150-3EF36-0AG0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection in distribution panels. It carries 50 A continuously at 40 °C and can interrupt up to 75.6 kA at 240 V AC — enough for high-fault utility feeds or transformer secondaries. The TM240 thermal-magnetic release provides fixed overload and short-circuit protection; there is no undervoltage release or communication module on this variant, so it is a straight replacement for existing fixed-trip MCCB slots without adding wiring complexity. Rated insulation voltage is 800 V, so it can be applied in 480/277 V or 600 V panels with headroom. The 70 mm depth and 76.2 mm width match the standard 3VA mounting footprint — drops into the same panel cutout as other 3VA three-pole frames without re-drilling.
Ratings that govern the real application
The 50 A rating holds flat from 40 °C through 50 °C ambient, then derates to 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. In a hot panel — say a poorly ventilated enclosure near a furnace line — expect to drop the continuous load to 45 A. The interrupting capacity steps down with voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at 500 V or 690 V. Coordination studies should use the voltage-specific SCCR, not the 240 V headline. Power loss is 14.6 W maximum — negligible for thermal budget in most enclosures, but worth noting if multiple breakers are ganged in a sealed box. The supplied basic switch is order code 3VA11503EF360AA0; the auxiliary switch configuration is one auxiliary plus one trip alarm switch (HP type).