What this MCCB is and what it does
The Siemens 3VA2040-7HL46-0AA0 is a SENTRON molded case circuit breaker (MCCB) built for line protection in distribution panels and motor control centers. It carries a continuous current rating of 40 A across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling, which simplifies panel design in hot enclosures. The 4-pole design handles three-phase plus neutral, and the ETU320 electronic trip unit gives adjustable overload and short-circuit protection curves.
Breaking capacity — what those numbers mean for fault duty
This breaker's interrupting capacity climbs with system voltage: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3 kA at 690 V. At typical 480 V industrial distribution, it clears 187 kA of prospective fault current — that's well above what most service-entrance panels see, so it's sized for high-fault locations like substation feeders or large motor control centers. The drop to 3 kA at 690 V is expected for this class; if you're running a 690 V line-up, confirm the available fault current stays under that threshold.
Mounting dimensions and panel fit
The 3VA2040-7HL46-0AA0 measures 140 mm wide, 181 mm tall, and 86 mm deep — a standard 4-pole MCCB footprint that drops into SENTRON 3VA2 switchgear or any DIN-rail-mounting panel with the right adapter. The IP40 front protection keeps dust and accidental contact out of the breaker face; fine for indoor panel installation, but it's not rated for washdown or outdoor exposure without an enclosure.
What the ETU320 trip unit gives you
The ETU320 is an electronic trip unit with adjustable overload and short-circuit settings. It draws a maximum power loss of 1.2 W.
Temperature range and storage handling
Operating range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. That storage floor matters if the breaker sits in an unheated warehouse over winter — it's fine down to -40 °C, but let it warm to operating temp before loading current. The 40 A rating holds across the entire operating band, no derating required up to 70 °C ambient.
What this breaker does not include
No undervoltage release, no shunt trip, no communication module, no trip indicator, and no voltage-trigger function. If your safety circuit requires undervoltage protection or remote tripping, you'll need an accessory add-on or a different 3VA2 variant. The line protection design means it's set up for feeder duty out of the box — not for motor-starting applications that need a higher magnetic pickup or adjustable time-delay curves.