What it is and what it carries
The Siemens 3VA1040-4ED32-0BC0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated for 40 A continuous current at 40 °C ambient, with a TM210 thermal-magnetic overcurrent release. It's the line-protection variant — no ground-fault monitoring, no communication module, no phase-failure detection. What it does carry is an undervoltage release (UVR) and two auxiliary switches (HQ type), so it's set up for remote trip indication and undervoltage protection out of the box.
Breaking capacity — the real number to watch
This breaker punches hard on fault interruption: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and still 11.9 kA at 690 V. For a 40 A frame, those are high-interrupting ratings — it'll clear a bolted fault on a large transformer secondary without the upstream fuse having to think about it. The 415 V figure is the one most panel builders will size against for 400 V distribution; 75.6 kA gives plenty of SCCR headroom for a typical industrial main lug.
Thermal derating and ambient limits
Rated 40 A from 40 °C through 50 °C ambient. At 55 °C it's 38.4 A; at 70 °C it's 36 A. That's a shallow derating curve — you lose only 4 A across a 30 °C rise, which means it runs cool in a crowded panel. The TM210 release is thermal-magnetic, so the thermal element tracks ambient; no need to manually adjust for seasonal temperature swings in a non-climate-controlled enclosure.
Panel fit and footprint
70 mm deep, 76.2 mm wide, 130 mm tall. That 76.2 mm width is the standard 3-pole MCCB footprint — it'll drop into a panel laid out for any SENTRON 3VA frame without re-drilling the mounting plate. The IP40 front face keeps dust out of the enclosure but isn't rated for washdown; this is a dry-indoor-panel breaker.