I looks like you are matching the circuit breaker/fuse to the item which
is drawing the load. This is one way to do it, but the way that I was
taught was to match the fuse to the wire which is feeding the current.
After all, the purpose of a fuse or circuit breaker is to prevent electrical
fire in the event of a short. It is not really important if the intercom is
drawing a bit more than 0.5 A, for example, but it is important if the
intercom is drawing so much current that the wires overheat.
The advantage of matching the fuse to the feed wire is you will not have any
nuisance trips and there will be a smaller variety of fuses. The advantage
of matching the fuse to the expected load is the ability to detect when a
device is drawing a small amount of current greater than expected. Finding
this out is usually not worth having the circuit breaker or fuse trip during
flight.
Brian
> Hi All,
>
> At risk of exposure of my lack of electical engineering ability, I am posting
> the planned circuit protection device ratings I am planning to use. I appeal
> to you experts in this field to correct any that need to be. I realize that
> the load pushed the limit of the Rotax alternator but these are not the
> actual loads, and I may make some adjustments to type equipment. I also
> realize they are not what is shown in every case on the Europa schematic, but
> some of them are left up to the builder anyway. What am I doing wrong by
> using these values of fuses or breakers?
> Thanks for all your opinions.
> Troy
>
> RC Allen Attitude Indicator------------------------------------3
> Turn Coordinator(imported)(like RC Allen) --------------3
> AV-10 Engine monitor------------------------------------------1.5
> Michell Electric Tach (redundant to monitor------------1
> Skysport Capacitance Fuel gage---------------------------1
> Fuel Pump@T.O.& Lnd (Facet)-----------------------------5
> Comm.Radio-------------------------------------------------------5
> Transponder--------------------------------------------------------5
> Alt. Encoder--------------------------------------------------------2
> Trim, Pitch(MAC)------------------------------------------------ 1
> AeroFlash Strobe------------------------------------------------ 5
> AeroFlash Nav/Tail Lite Combo ---------------------------- 7.5
> Landing Lite(55w)-----------------------------------------------10
> Instrument Lites---------------------------------------------------2
> Aux Panel Outlet-------------------------------------------------5
>
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