The Siemens 3VA1150-6EF36-0KA0 is a 3VA1 IEC frame 160 molded case circuit breaker in breaking capacity class H. It's a 3-pole unit rated In=50A with a TM240 thermal-magnetic trip unit providing overload protection adjustable Ir=35A...50A and short-circuit protection Ii=5...10 x In. The interrupting rating hits Icu=70kA @ 415V — that's the class H threshold, meaning it clears high fault currents on a 415 V line without the arc re-striking, so it's sized for main feeder or large motor branch protection where available fault current is substantial.
What the ratings mean for fit
The TM240 trip unit is the key selection parameter: overload Ir is adjustable from 35 A to 50 A via a dial on the front, so you set it to the actual continuous load current — not the breaker frame rating. The short-circuit pickup Ii is fixed at 5 to 10 times In (250 A to 500 A at the 50 A setting), which is a fixed magnetic trip, not electronic. That means it's a straightforward thermal-magnetic curve for general distribution or motor branch circuits where coordination with downstream devices is done by time-current curves, not by a digital trip unit. The shunt trip (STL) coil takes 220-250 V DC or 208-277 V AC, so it can be wired to a remote emergency-stop pushbutton or a safety relay without an interposing relay — saves a panel component.
Integration and connections
Clamp (box lug) connections on the line and load side — no tunnel terminals, so you torque down a single screw per phase. Accepts aluminum or copper conductors typical for 50 A feeder circuits. The 3VA1 frame is a standard panel-mount molded case breaker; it occupies three pole spaces on a DIN rail or a mounting plate. The shunt trip adds a pair of control wires; verify polarity on the DC version if you're wiring it to a 220 V DC control bus.