Alternator wiring

On Feb 18, 12:08 pm, Sliker wrote:
I'm wiring the electrical system in my Glasair 3, and would like to
know how most builders wire the alternator. It seems every diagram I
get from Bob Nuckolls shows the alternator supply wire (B) connecting
to the input side of the starter contactor. But the wiring diagrams
from B&C show the B wire going directly to the supply or main bus
through a circuit breaker of appropriate amps. The main difference I
see is with Nuckolls method, the alternator has to send it's current
through the battery contactor. Where as the B&C diagram bypasses it
and goes directly to the main bus. Which is better?

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The input side of the starter contactor is connected to
the output side of the master contactor, and a heavy line goes from
that same point to feed the bus through the ammeter. Connecting the
alternator to that terminal will run all its current through the
ammeter, which you don't want. The ammeter would show a discharge even
though the battery is charging.
Run the line to the bus, through a breaker. The ammeter will
then read properly, and you will have a protected circuit.

Dan

On Mon, 18 Feb 2008 17:41:38 -0800 (PST),
wrote:

On Feb 18, 12:08 pm, Sliker wrote:
I'm wiring the electrical system in my Glasair 3, and would like to
know how most builders wire the alternator. It seems every diagram I
get from Bob Nuckolls shows the alternator supply wire (B) connecting
to the input side of the starter contactor. But the wiring diagrams
from B&C show the B wire going directly to the supply or main bus
through a circuit breaker of appropriate amps. The main difference I
see is with Nuckolls method, the alternator has to send it's current
through the battery contactor. Where as the B&C diagram bypasses it
and goes directly to the main bus. Which is better?

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----------------------------------------------------------
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The input side of the starter contactor is connected to
the output side of the master contactor, and a heavy line goes from
that same point to feed the bus through the ammeter. Connecting the
alternator to that terminal will run all its current through the
ammeter, which you don't want. The ammeter would show a discharge even
though the battery is charging.
Run the line to the bus, through a breaker. The ammeter will
then read properly, and you will have a protected circuit.

Dan

That's what I was leaning towards. I don't think the noise Bob
mentions on the B lead from the alternator is all that bad. In a
composite bird, it might be a little worse than in a metal one, but I
plan to make good grounds. And I can always shield the wire with some
extra shielding. Plus, looking at Bob's wiring diagrams, they all
incorporate a main bus and an essential bus. I'm just going to use one
main bus. If it all fails, I'll get out the handheld and pump the gear
down if the battery can't handle it. His systems have a main bus,
essentail bus, hot battery bus, battery bus, and ground power bus. And
probably coming next is auto load shedding. I haven't seen some of
those items since 737 ground school. One shouldn't have to go to
ground school to check out in a Glasair 3. And spend a day on the
eletrical system alone :-) Although it would be neat to have all that
stuff just to watch people freak when describing it all.