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On 6/26/04 2:51 PM, "Dale Rogers" <rogersda@cox.net> wrote:
>
>> From: "Ed Anderson" <eanderson@carolina.rr.com>
>> Date: 2004/06/26 Sat PM 12:33:09 EDT
>> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
>> Subject: [FlyRotary] Re: LS1 Coils and Harness II
>>
>> The terminals for the plugs will handle 16-18 AWG wire and are rated for 14
>> amps, so even 18 AWG should be more than adequate for a single coil.
>
>
> Hi All,
>
> This seems to be an area where I'm going to have to reorient
> my thinking. For years, I've been wiring trailers and after-
> market accessories, and I've often been appalled at the barely-
> adaquate wiring I've found in place. I've used far more 14g wire
> than 16 or 18, just to be sure it was safe.
>
> Now I'm facing the wiring of an airplane, and 14g - besides
> being harder to find in Mil-22759 - is _heavier_ than 16 or 18g.
>
> I'm going to have to pay a lot more attention to what current
> my circuits will be expected to carry and use wire that will
> *just* to the job (with an appropriate safety factor, of course.)
>
> And it isn't just the instantaneous load I have to consider.
> In the case of the coil, wasn't the instantaneous draw about 9A?
> But that's pulsed DC. The RMS flow is probably considerably
> less, but how much less? Using Bob Nuckols' chart, it appears
> that 18g wire is good for 7A before the temperature increase
> breaks 10*C; if I don't mind wasting some watts, I get push 10A
> through it for a 35 degree increase. But that's for 100% duty
> cycle; what's the duty cycle of one coil at 6000 rpm? If it
> was - say - 50%, then 18g would be plenty.
>
> Learning all this, to finish this aircraft is definitely going
> to stretch my talents a bit.
>
> Dale R.
> COZY MkIV-R13B #1254
>
Dale, you may have this one, but here it is again. A spreadsheet that
calculates the wire size if you enter the Amp and distance.
--
Bulent Aliev
Stretched CZ MK-IV W/Turbo Rotary
Ft Lauderdale, FL FXE
http://home.bellsouth.net/p/PWP-MyPlane
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