B-Line Eaton Series C complete , F-, FD, Complete , Fixed thermal, fixed magnetic trip type, Single-pole, 40A, 347 Vac, 125 Vdc, 35 kAIC at 277 Vac,

The FD1040V is rated 347 Vac and 125 Vdc, so it will work on the 347V line-to-neutral leg of a 600/347V wye system as a single-pole device. Interrupting capacity drops at that voltage: 35 kAIC at 277 Vac but only 18 kAIC at 347 Vac. Check your available fault current at the panel against the 18 kAIC figure before applying it at 347V.

It ships as a complete breaker in the Eaton Series C F-frame. There is no separate trip unit, rating plug, or frame to order with it, since the trip is fixed thermal, fixed magnetic at 40A.

No. The FD1040V uses a fixed thermal, fixed magnetic trip, so both the overload and the instantaneous pickup are factory set and non-adjustable at 40A. If your application needs field-adjustable instantaneous or an electronic trip with adjustable settings, an FD frame with a fixed trip is the wrong choice and you want an adjustable or electronic-trip breaker instead.

FD1040V is the exact Eaton catalog number: Series C, F-frame, FD type, single-pole, 40A. If the breaker you are replacing is marked FD1040V, this is a direct match. If your existing unit is a different FD suffix, the voltage or interrupting rating differs and you should match the full catalog number rather than just the FD and amperage.

Calibration is 50 degrees C ambient, which is higher than the 40 degree C calibration common on many breakers. That means the 40A rating holds in warm enclosures and mechanical rooms without the derate you would apply to a 40 degree C calibrated device.

Terminals are load side on this breaker. Plan your conductor routing accordingly, and confirm the line side connection method your panel or enclosure requires before you set the breaker in place.

Yes, the breaker carries a 125 Vdc rating alongside its ac ratings, so it can be applied on 125 Vdc systems such as switchgear control power or battery distribution at 40A single-pole.

Frequency rating is 50/60 Hz, so it is suitable for both North American 60 Hz systems and 50 Hz installations, including packaged equipment built for export.

Published dimensions are 6 x 1 x 1 inches and the unit weighs 1 lb, so a single-pole FD takes minimal width in a panel or a small enclosure. Use those figures for layout only; wiring bending space and gutter clearance are set by your enclosure, not the breaker.