Siemens 3VA1140-4GE46-0AA0 — 40 A MCCB with TM220 trip unit
The Siemens 3VA1140-4GE46-0AA0 is a 4-pole molded case circuit breaker from the SENTRON series, rated 40 A continuous with a TM220 thermal-magnetic overcurrent release. It's designed for line protection in distribution panels and switchgear. Breaking capacity is 121 kA at 240 V AC, dropping to 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V — that covers most industrial fault-current scenarios without needing a current-limiting upstream device.
Thermal derating and ambient temperature
The breaker carries its full 40 A rating up to 50 °C ambient. Above that, it derates gradually: 39 A at 55 °C and 60 °C, 38 A at 65 °C, and 37 A at 70 °C. If your panel runs hot — say, near a VFD cabinet or in a non-climate-controlled enclosure — factor that 3 A drop at the top end into your load schedule. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The IP40 front protection means it's fine in a clean indoor panel but not for washdown areas.
Dimensions and panel fit
The breaker measures 130 mm high, 101.6 mm wide, and 70 mm deep — a standard 4-pole MCCB footprint. It fits most DIN-rail or panel-mount enclosures without surprises; the 70 mm depth leaves room behind the door for wiring and auxiliary contacts.