What this MCCB is and what it protects
The Siemens SENTRON 3VA1196-4EF36-0BH0 is a 3-pole molded case circuit breaker (MCCB) rated for 16 A continuous current at 40 °C, with a line-protection design — meaning it's built for feeder and distribution circuits, not motor-starting duty. The 121 kA breaking capacity at 240 V AC tells you it can interrupt very high fault currents without the arc re-striking; at 415 V AC that figure drops to 75.6 kA, and at 690 V AC it's still rated at 11.9 kA. That's a lot of headroom for most industrial panels, so selectivity with downstream breakers is achievable even on large-transformer secondaries.
Auxiliary and undervoltage release configuration
This variant ships with two auxiliary switches plus one trip-alarm switch (HQ type) and an undervoltage release (UVR) factory-installed. The UVR trips the breaker when control voltage drops below a set threshold — useful for safety circuits where loss of a control supply must open the main power path. The auxiliary contacts let a PLC or SCADA system read the breaker's open/closed and tripped states without extra interposing relays. All fit within the standard 76.2 mm width, so no extra DIN-rail space is consumed.
Thermal derating and panel integration
The 16 A rating holds from 40 °C up to 55 °C ambient, then derates to 15 A at 60 °C and stays there through 70 °C. That's a shallow derating curve — useful if the breaker sits in a warm enclosure near other heat sources. Power loss at full load is 13.1 W maximum, so factor that into your enclosure thermal calculation. Dimensions are 130 mm height, 76.2 mm width, 70 mm depth; the depth is the key number for gland-plate clearance in shallow backboards.