What it is and what it does
The Siemens SENTRON 3VA1196-4EF36-0KA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection. It carries a 16 A rated current across ambient temperatures up to 55 °C, derating to 15 A at 60–70 °C. The 121 kA breaking capacity at 240 V is the headline number for fault-clearing capability; at 415 V it still interrupts 75.6 kA, and at 690 V it holds 11.9 kA. That kind of headroom matters when you're coordinating selectivity downstream of a transformer — the 121 kA figure tells you this breaker can sit at the main or feeder position in a high-fault panel without worrying about cascading failure upstream.
What the ratings mean for fit
The 16 A rating is the continuous current the breaker carries without tripping — sized for a 16 A feeder or branch circuit. The thermal-magnetic release (TM240) handles overloads and short-circuits. The shunt trip (STL) auxiliary release lets you remotely trip the breaker via a control signal, which is useful for emergency-stop circuits or automated shutdown sequences. Rated insulation voltage is 800 V, so the breaker's internal clearances and creepage are designed for 690 V systems with margin. Power loss at rated load is 10.6 W — negligible for most panels but worth noting if you're packing several breakers in a sealed enclosure.
Where it goes in the panel
This MCCB mounts on a DIN rail or directly to a backplate via the standard SENTRON footprint. Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep — the 3-pole width of roughly 3 inches means it occupies three 18 mm module spaces on the rail. No communication function, no undervoltage release, no ground-fault monitoring on this variant — it's a straight line-protection breaker with a shunt trip for remote opening. If you need those extras, you're looking at a different suffix in the 3VA family.