In a message dated 18/07/96 10:34:33, you write:
> It looks like Europa (and R&D) decided to bring the full alternator
>load
>through the firewall and into the panel (Rotax output is 25A). This is also
>the
>noisiest electrical field on the plane, so Alan Thorne and myself decided to
>change things slightly to keep the run as short as possible.
Am I right in thinking the rectifier part of the Rotax is a separate entity
to the field coils (unlike a car where this is combined). Presumably the
reason for keeping the circuitry on the engine side of the firewall is
because its AC.
You say the Rotax output is 25A. I was under the impression that it was only
18.5A (Rotax quote 250 watts). Or is this the current on the AC side of the
rectifier. It would certainly be useful to have the extra current available
(pitot heat perhaps !). A large chunk of my current is used up on the Wheelen
strobes.
Regarding the matter of fuses versus CB's, it can only be said that fuses
also fail occasionally and it would be a pity to have to terminate a flight
if this was the only problem. The trouble is that if this was mounted on the
engine side you would have no option but to land.
Since this is such an important circuit perhaps it would be an idea to
protect it with two CB's in parallell (but to keep one off as a standby).
These could be mounted upside down on the ceiling side of the footwell with
the back end protruding into the "shelf" area of the engine compartment. If
the breakers popped it would be fairly easy to see and get at but at the same
time keeping the nasty AC engine side of the FW. I am of course assuming that
there is some form of shielding covering the entire area of the firewall
otherwise the whole exercise is pointless anyway.
I have purchased several cans of RFI shielding spray for this purpose and
had intended to coat both cowlings and the firewall face. This is an RS
product (code 568-483).
BTW im glad to hear that Alan Thorne is still a builder. As we hadnt heard
---From him since relinquishing his Editorship of the Europa Flyer we assumed he
had given up. It was encouraging to read Alans regular bulletins to the PFA
magazine on the progress of his aircraft. Hopefully its now nearly finished.
Carl Pattinson
Kit 49
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