Alternator wiring

On Feb 19, 12:38 pm, Sliker wrote:

Sounds like another reason not to use that alternator wiring method. I
also remember reading about him mentioning using a high amperage rated
shunt for the amp meter when used in that location. The issues seem to
snowball. I have one question, if the B lead were hooked up to the
starter contactor, would reversing the wires on the amp meter make it
read correctly?

Nope. Now it would read "charge" all the time, even during discharge.

The ammeter is an indication of what the battery is doing.
It needs to be wired as shown so that there are two directions of
electron flow so you know whether the alternator is managing to keep
up or not. If the alternator's output isn't wired to the bus itself
rather than the contactor, you'll have no idea if it's working
properly. The ammeter won't be able to tell you anything worthwhile.

Dan

On Tue, 19 Feb 2008 12:50:02 -0800 (PST),
wrote:

Nope. Now it would read "charge" all the time, even during discharge.

The ammeter is an indication of what the battery is doing.
It needs to be wired as shown so that there are two directions of
electron flow so you know whether the alternator is managing to keep
up or not. If the alternator's output isn't wired to the bus itself
rather than the contactor, you'll have no idea if it's working
properly. The ammeter won't be able to tell you anything worthwhile.

Dan
'
Ah, that explains some other issue I have. In my flying homebuilt,
(the one I had to buy that was finished and flying because I didn't
know it would take so many years to complete my Glasair) It's amp
meter only shows a charge, but will never indicate a discharge. It
just goes to the center position when there's a load and the
alternator isn't turning. So where I the best place to install a
shunt? I need to rewire that darn thing.
Rich

On Feb 19, 7:27 pm, Pelican wrote:
Ah, that explains some other issue I have. In my flying homebuilt,
(the one I had to buy that was finished and flying because I didn't
know it would take so many years to complete my Glasair) It's amp
meter only shows a charge, but will never indicate a discharge. It
just goes to the center position when there's a load and the
alternator isn't turning. So where I the best place to install a
shunt? I need to rewire that darn thing.
Rich

Sounds like the ammeter is installed in the alternator's
output line. Doesn't belong there. A shunt won't fix that. The ammeter
should be connected like the diagram in that website I pointed out
ealrier: between the master contactor and the bus. Do that and all
will be fine. Piper used a loadmeter for some years, which was an
ammeter that had its zero position on the left instead of center, and
was used to indicate the alternator's output. Maybe that's what the
builder of your airplane was thinking of when he connected it between
the alternator and bus.

Dan