What this MCCB does for your panel
The Siemens 3VA1150-4EF32-0HH0 is a 3-pole SENTRON molded case circuit breaker rated for 50 A continuous current, with a TM240 thermal-magnetic release for line protection. The 121 kA interrupting capacity at 240 V gives you headroom on high-fault panels; at 415 V it still holds 75.6 kA, and at 690 V it's rated 11.9 kA — so the same breaker works across 240 V, 400 V, and 690 V distribution without swapping frames. The 70 mm depth and 76.2 mm width fit standard MCCB mounting patterns, and the IP40 front keeps dust out of the enclosure cutout.
Current derating and temperature
Rated continuous current Iu is 50 A, and it holds that rating from 40 °C up to 50 °C without derating. Above that, it steps down: 48 A at 55 °C, 47 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If the panel runs hot — say, a packed enclosure near a furnace line — plan for that 45 A ceiling at the top end. The TM240 release is a fixed thermal-magnetic type, so no interchangeable trip units to swap; what you order is what you get.
Auxiliary contacts and trip alarm
Comes with 2 auxiliary switches plus 1 trip alarm switch (HQ version). That means you get both a status mirror for the breaker position and a separate signal for fault tripping — useful for feeding a PLC input or annunciator without extra relays. The trip indicator is built in, and the voltage trigger (shunt trip) is present; undervoltage release and phase failure detection are not fitted on this variant.
Environmental and mechanical
Operating temperature range is -25 °C to 70 °C; storage range goes from -40 °C to 80 °C, so it can sit in an unheated warehouse or truck without issue. Mechanical endurance is rated at 15,000 operations — that's the latching cycle count, not electrical, so it's fine for occasional switching but not a daily motor-start duty. Rated insulation voltage Ui is 800 V, matching the 690 V interrupting rating.