B-Line Eaton Series C complete , F-, FD, Complete , Fixed thermal, Fixed magnetic trip type, Three-pole, 40 A, 600 Vac, 250 Vdc, Load side, 50/60 Hz

It ships as a complete breaker, not a trip unit or replacement guts. The FD is an F-frame device in Eaton's Series C molded case line, so you are getting the full assembly ready to mount and land conductors on.

No. The FD3040 uses a fixed thermal, fixed magnetic trip. There is no adjustable magnetic dial and no interchangeable trip unit, so the 40 amp rating is what you get. If the design calls for an adjustable instantaneous setting, you need a different trip type, not this one.

The breaker measures 6 in high, 4.13 in wide and 3.38 in deep, and weighs 4.5 lb. Use those numbers to confirm gutter space and cover cutout before you commit, particularly on a retrofit into an older enclosure.

Terminals are specified load side on this FD3040. Line side connection method should be confirmed against your panel arrangement, since a plug-in or bus-connected installation does not use line lugs at all.

Order Eaton part number FD3040. The number reads directly: FD frame designation, 3 poles, 40 amps. It is a single configuration, so there are no suffixes to pick.

The FD3040 is rated 65 kAIC at 240 Vac, which covers most distribution panel locations downstream of the service. Whether it is enough is decided by the available fault current at that point in your system, taken from the short circuit study, not by the breaker alone. Close to a large transformer the available current can exceed this, and there a higher interrupting frame or a series-rated combination is what the design will call for.

Yes, within its rating. The FD3040 carries a 250 Vdc rating alongside 600 Vac, so DC applications up to 250 volts are covered at the same 40 amp, three-pole configuration. DC installations normally require poles in series per the manufacturer's DC connection arrangement, so follow the wiring diagram supplied with the breaker.