The Siemens 3VM1150-4GE42-0AA0 is a 4-pole circuit breaker on the 3VM1 IEC frame 160, rated 50 A with a TM220 thermal-magnetic trip unit. That is the spec that decides whether it coordinates with your existing switchgear's SCCR. Overload protection is adjustable Ir = 35 A to 50 A (the TM220 dial range), so you set it to match the continuous load current of the downstream feeder — cable or busway — not the breaker's 50 A nameplate. Short-circuit magnetic pickup is fixed at 10 × In (500 A), which is a standard motor-starting withstand level for a general-purpose line-protection breaker. The N-conductor protection is 100 %, meaning the neutral pole trips at the same threshold as the phase poles — required on 4-wire systems where the neutral carries harmonic currents.
Sourcing and lifecycle — what a buyer needs to know
RoHS compliant since June 2012; REACH Article 33 duty applies due to lead content above 0.1 % w/w (CAS 7439-92-1) in the candidate list. The certification note on the description line indicates CE and EEQCO Scheme-X are available; UL/CSA are not listed for this variant, so verify with your local inspector if the installation requires a UL-listed breaker.
Panel integration — DIN rail and enclosure fit
Four-pole construction means it occupies the full width of the frame — plan for a 72 mm module width (typical for this frame size). The line and load terminals accept copper or aluminum conductors up to the frame rating; torque values are on the label. The nut keeper kit included in the description ensures the terminal screws stay captive during wiring — a small thing that saves time on a panel build.