Siemens SENTRON 3VA1112-3EF42-0AA0 — 125 A MCCB, 4-Pole, Line Protection
The Siemens SENTRON 3VA1112-3EF42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated 125 A at 40 °C, designed for line protection in distribution panels and industrial switchgear. Its TM240 thermal-magnetic overcurrent release provides fixed thermal and magnetic trip settings, making it a straightforward choice for feeder or main breaker duty where adjustable trip units are not required. Breaking capacity reaches 75.6 kA at 240 V AC, 52.5 kA at 415 V, and 32 kA at 440 V — sufficient for high-fault-current installations common in North American and European industrial networks. The 4-pole configuration covers three-phase plus neutral switching, typical for TN-S or TT systems where the neutral must be isolated. Rated insulation voltage is 800 V, and the front face carries IP40 protection — suitable for panel-mount indoor use where tools or fingers are the main concern, not washdown. The breaker lacks a trip indicator, undervoltage release, and communication functions; it is a basic thermal-magnetic MCCB without accessories or remote monitoring.
Dimensions & Panel Fit
The breaker measures 130 mm high, 101.6 mm wide, and 70 mm deep. The 4-pole width (101.6 mm) matches the standard 4-module footprint for SENTRON 3VA MCCBs, so it drops into existing panel cutouts or DIN-rail adapters without rework. Depth of 70 mm leaves clearance for rear-mounted busbars or cable ducts.
Thermal Derating & Operating Range
Rated current holds at 125 A from 40 °C up to 50 °C, then derates linearly to 114 A at 70 °C. For panels running near the upper ambient limit, the 70 °C rating (114 A) is the figure to use for continuous load sizing. Operating ambient range is -25 °C to +70 °C; storage range is -40 °C to +80 °C. Maximum power loss is 28.1 W at rated load — a modest figure that simplifies thermal management inside the enclosure. No ground-fault monitoring or communication function is built in; this is a pure overcurrent protection device.