MCCB for high-fault panels
The Siemens 3VA1112-5EF36-0AC0 is a SENTRON 3-pole molded case circuit breaker rated for 125 A continuous current (Iu) with a TM240 thermal-magnetic release. It carries a 187 kA interrupting capacity at 240 V, dropping to 121 kA at 415 V and 75.6 kA at 440 V, which covers most industrial service-entrance and feeder applications where fault current runs high. The 800 V rated insulation voltage (Ui) keeps it suitable for 480 V and 600 V class panels.
Current derating and thermal limits
This breaker holds its full 125 A rating up to 50 °C ambient. Above that, it derates to 120 A at 55 °C, 117.5 A at 60 °C, 115 A at 65 °C, and 112.5 A at 70 °C. If your panel runs hot — say, near a drive cabinet or in a non-climate-controlled enclosure — the 70 °C figure is the one to size against. The TM240 release is fixed, not adjustable, so coordination studies should use the published trip curve.
Panel fit and auxiliary contacts
The 3VA1112-5EF36-0AC0 measures 76.2 mm wide, 130 mm tall, and 70 mm deep. The IP40 front protection means it's fine for a deadfront enclosure but not for washdown areas. It ships with two HQ auxiliary switches built in — no separate add-on module needed for status feedback to a PLC or indication lamp. No undervoltage release, no shunt trip, no communication module on this variant.