The Siemens 3VA4145-4ED34-3AA0 is a 3-pole circuit breaker from the 3VA4 series, UL Frame 125, rated 45 A continuous with a breaking capacity of 25 kA at 480 V. The TM210 trip unit gives you thermal-magnetic protection: the thermal element (Ir) is permanently set at 45 A for overloads, and the magnetic instantaneous pickup (Ii) is fixed at 10x In (450 A) for short circuits. No field adjustment on the trip settings — what you order is what protects the feeder.
RoHS compliant since May 2019.
The 3-pole format occupies three module widths (about 54 mm). With the TM210 fixed-trip thermal-magnetic unit, there's no adjustment knob to reach — good for sealed panels where you don't want settings changed in the field. The load-side terminals accept copper or aluminum conductors up to the frame rating; torque per the nameplate values.