SENTRON 3VM1040-3ED42-0AA0 — 40 A MCCB for Panel Builds
The Siemens SENTRON 3VM1040-3ED42-0AA0 is a 4-pole molded case circuit breaker rated for 40 A continuous current, with a TM210 thermal-magnetic release and adjustable Ir up to 40 A and Ii up to 400 A. It's built for line protection in distribution panels, with a compact footprint — 101.6 mm wide, 130 mm tall, 70 mm deep — that fits standard enclosure layouts. Breaking capacity is the headline: 76 kA at 240 V AC, 53 kA at 415 V, 32 kA at 440 V, and 7.5 kA at 500 V. That gives you selectivity headroom downstream of a larger main breaker — the 53 kA at 415 V is where most industrial panels in that voltage class need the margin.
Thermal Derating — Know Your Ambient
This breaker carries its full 40 A rating from 40 °C up through 50 °C. At 55 °C it derates to 39 A, holds there through 60 °C, then drops to 38 A at 65 °C and 37 A at 70 °C. If your panel runs hot — say a packed enclosure near a furnace line — that 70 °C ceiling still leaves you 37 A of continuous capacity. The storage range is -40 °C to 80 °C, so it handles warehouse and transit extremes without issue.
Integration Notes
IP40 on the front face means it's protected against tools and wires >1 mm — standard for enclosed panel mounting. The 4-pole design handles three-phase plus neutral, or can serve as a main disconnect in a 3-phase panel with a switched neutral. Rated insulation voltage is 690 V, so it's comfortable in 400 V and 480 V systems with margin. No communication module, no ground-fault monitoring — this is a straight thermal-magnetic breaker for basic overcurrent and short-circuit protection.