Line protection MCCB with high interrupting capacity
The Siemens SENTRON 3VA1150-6EF36-0BH0 is a 3-pole molded case circuit breaker rated for 50 A continuous current at 40 °C, with a TM240 thermal-magnetic overcurrent release. Its interrupting capacity reaches 220 kA at 240 V, 154 kA at 415 V, and 121 kA at 440 V — figures that place it in the high-fault-current class for industrial main feeders and large sub-distribution boards. The 800 V rated insulation voltage (Ui) means it can be applied in 480 V and 600 V class systems without derating the insulation path. The breaker includes an undervoltage release (UVR) as the auxiliary release design, plus a set of 2 auxiliary switches and 1 trip alarm switch (HQ type) for remote status indication. The TM240 release is a fixed thermal-magnetic type — no interchangeable trip units, so the 50 A rating is locked at manufacture. A mechanical trip indicator is present on the front face.
Thermal derating and panel integration
The 3VA1150-6EF36-0BH0 holds its full 50 A rating up to 50 °C ambient. Above that, it derates linearly: 48 A at 55 °C, 47 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. The operating temperature range is -25 °C to 70 °C; storage range extends from -40 °C to 80 °C. Front protection is IP40 — suitable for enclosed panel mounting where the breaker face is behind a closed door. Dimensions are 130 mm height, 76.2 mm width, 70 mm depth, which fits the standard SENTRON 3VA mounting footprint on a DIN rail or screw-fixed backplate.
Selectivity and coordination notes
With 220 kA interrupting capacity at 240 V and 154 kA at 415 V, this breaker is sized for high-fault-current locations such as transformer secondaries or large motor control center mains. The TM240 release provides thermal protection for overloads and magnetic (instantaneous) protection for short circuits. For DC network applications, the manufacturer directs to the 3VA device manual for specific switching power values — this variant is primarily an AC line protection device. Latching endurance is rated at 15,000 operations.