Alt. question

[sky bob]

I am building a Long EZ and am the stage where I am ready to start the
engine installation and have a couple questions for the group. The
Alt. that I have is a small single wire 60 amp alt W/ a built in
regulator that I will be putting on a Lyc. 0-235 my quastions are as
follows. 1. Is there a way of turning the alt. off if the regulator
were to stick and continue to charge the batt. even though it were
fully charged? I have heard of this happeningand almost blowing up the
batt. I've also heard that even if I were to shut the voltage (12V)
off to the atl that it could still send a charge to the batt as long
as the engine is turning the pulley. 2. What size wire would be
recommended to carry the voltage from the alt. to the batt. that is
located in the nose of the plane (maybe 10-12').

Thanks for your suggestions.

Sky Bob
Brunswick, GA

[Anthony W]

It would be impossible for the alternator to continue to make power if
the wire to it were disconnected. There would be no power to the field
coil and therefor no output. Even if it were to somehow magically make
power, it couldn't deliver it only

I would use a relay rather than 12' of 12 gage wire but that's up to you...

Tony

sky bob wrote:
> I am building a Long EZ and am the stage where I am ready to start the
> engine installation and have a couple questions for the group. The
> Alt. that I have is a small single wire 60 amp alt W/ a built in
> regulator that I will be putting on a Lyc. 0-235 my quastions are as
> follows. 1. Is there a way of turning the alt. off if the regulator
> were to stick and continue to charge the batt. even though it were
> fully charged? I have heard of this happeningand almost blowing up the
> batt. I've also heard that even if I were to shut the voltage (12V)
> off to the atl that it could still send a charge to the batt as long
> as the engine is turning the pulley. 2. What size wire would be
> recommended to carry the voltage from the alt. to the batt. that is
> located in the nose of the plane (maybe 10-12').
>
> Thanks for your suggestions.
>
> Sky Bob
> Brunswick, GA

[[email protected]]

On Jun 8, 1:43*pm, Anthony W > wrote:
> It would be impossible for the alternator to continue to make power if
> the wire to it were disconnected. *There would be no power to the field
> coil and therefor no output. *Even if it were to somehow magically make
> power, it couldn't deliver it only
>
> I would use a relay rather than 12' of 12 gage wire but that's up to you....
>
> Tony
>
Impossible ?? Not hardly.... Residual magnetism in the field coil can
give output especially if unloaded.
If regulator pass transistor is shorted, output can go max until
transistor burns open.
An external regulator is usually recommended for A/C applications.

Read this Aeroelectric connection article..
http://www.aeroelectric.com/articles/Adapting_IR_Alternators_to_Aircraft.pdf

Reggie

[Anthony W]

Residual magnetism is a minuscule compared to the draw of only the dash
lights. Besides if you cut the feed to the power wire, where is it
going to go?

Tony

wrote:
> On Jun 8, 1:43 pm, Anthony W > wrote:
>> It would be impossible for the alternator to continue to make power if
>> the wire to it were disconnected. There would be no power to the field
>> coil and therefor no output. Even if it were to somehow magically make
>> power, it couldn't deliver it only
>>
>> I would use a relay rather than 12' of 12 gage wire but that's up to you...
>>
>> Tony
>>
> Impossible ?? Not hardly.... Residual magnetism in the field coil can
> give output especially if unloaded.
> If regulator pass transistor is shorted, output can go max until
> transistor burns open.
> An external regulator is usually recommended for A/C applications.
>
> Read this Aeroelectric connection article..
> http://www.aeroelectric.com/articles/Adapting_IR_Alternators_to_Aircraft.pdf
>
> Reggie
>

[[email protected]]

On Jun 8, 2:43 pm, Anthony W > wrote:
> It would be impossible for the alternator to continue to make power if
> the wire to it were disconnected. There would be no power to the field
> coil and therefor no output.

In an alternator with an integral regulator the output feeds the
regulator via an internal connection and therefore the field. It'll
still produce. But if the output to the aircraft is run to a pullable
breaker on the panel, it can be shut off and the alternator can go
play with itself. Only problem is that the output line to the breaker
is still live and can cause trouble in the event of a fire or forced
landing.

Dan

[routund]

sky bob > wrote:

>I am building a Long EZ and am the stage where I am ready to start the
>engine installation and have a couple questions for the group. The
>Alt. that I have is a small single wire 60 amp alt W/ a built in
>regulator that I will be putting on a Lyc. 0-235 my quastions are as
>follows. 1. Is there a way of turning the alt. off if the regulator
>were to stick and continue to charge the batt. even though it were
>fully charged? I have heard of this happeningand almost blowing up the
>batt. I've also heard that even if I were to shut the voltage (12V)
>off to the atl that it could still send a charge to the batt as long
>as the engine is turning the pulley. 2. What size wire would be
>recommended to carry the voltage from the alt. to the batt. that is
>located in the nose of the plane (maybe 10-12').
>
>Thanks for your suggestions.
>
>Sky Bob
> Brunswick, GA

The response to check the aeroelectric site for information on alternator
installation was a good one. We used one of their over voltage protection
circuits on an externally regulated alternator. I do not have any experience
with an internal regulator. If you use their (Aeroelectric) over voltage
protector and an inline fuse to the alternator that would probably work. The
idea behind the over voltage protector is that it will create a short circuit
when the voltage exceeds a given design voltage. That short circuit will then
cause the current to rise in the supply wire until the fuse rating of the supply
wire fuse is exceeded and it melts, opening the circuit and removing the supply
voltage to the alternator.

Per your second question, you will need to calculate the total load that the
alternator is going to be supplying. From that and a wire sizing table you can
calculate the size wire needed. At a guess I would say that a 10 AWG should be
more than adequate for your application. The 10 AWG is good for 30 amperes and
will supply that load with a 2% drop over the 10 feet.

[[email protected]]

On Mon, 8 Jun 2009 21:36:59 -0700 (PDT),
wrote:

>On Jun 8, 2:43 pm, Anthony W > wrote:
>> It would be impossible for the alternator to continue to make power if
>> the wire to it were disconnected. There would be no power to the field
>> coil and therefor no output.
>
>In an alternator with an integral regulator the output feeds the
>regulator via an internal connection and therefore the field. It'll
>still produce. But if the output to the aircraft is run to a pullable
>breaker on the panel, it can be shut off and the alternator can go
>play with itself. Only problem is that the output line to the breaker
>is still live and can cause trouble in the event of a fire or forced
>landing.
>
>Dan

Not the only problem. If the alternator full fields offline voltage
can excede 300 volts in the alternator - and that voltage goes to the
feild. The alternator WILL destroy itself in this case - and it CAN
burn.

I would definitely want the alternator modified so the feild is
externally fed ONLY.

[[email protected]]

On Jun 9, 9:57*pm, wrote:
> On Mon, 8 Jun 2009 21:36:59 -0700 (PDT),
> wrote:
>
> >On Jun 8, 2:43 pm, Anthony W > wrote:
> >> It would be impossible for the alternator to continue to make power if
> >> the wire to it were disconnected. *There would be no power to the field
> >> coil and therefor no output.
>
> >In an alternator with an integral regulator the output feeds the
> >regulator via an internal connection and therefore the field. It'll
> >still produce. But if the output to the aircraft is run to a pullable
> >breaker on the panel, it can be shut off and the alternator can go
> >play with itself. Only problem is that the output line to the breaker
> >is still live and can cause trouble in the event of a fire or forced
> >landing.
>
> >Dan
>
> Not the only problem. If the alternator full fields offline voltage
> can excede 300 volts in the alternator - and that voltage goes to the
> feild. The alternator WILL destroy itself in this case - and it CAN
> burn.
>
> I would definitely want the alternator modified so the feild is
> externally fed ONLY.

And how would you go about doing that?

Bob

[jerry wass]

wrote:
> On Jun 9, 9:57 pm, wrote:
>> On Mon, 8 Jun 2009 21:36:59 -0700 (PDT),
>> wrote:
>>
>>> On Jun 8, 2:43 pm, Anthony W > wrote:
>>>> It would be impossible for the alternator to continue to make power if
>>>> the wire to it were disconnected. There would be no power to the field
>>>> coil and therefor no output.
>>> In an alternator with an integral regulator the output feeds the
>>> regulator via an internal connection and therefore the field. It'll
>>> still produce. But if the output to the aircraft is run to a pullable
>>> breaker on the panel, it can be shut off and the alternator can go
>>> play with itself. Only problem is that the output line to the breaker
>>> is still live and can cause trouble in the event of a fire or forced
>>> landing.
>>> Dan
>> Not the only problem. If the alternator full fields offline voltage
>> can excede 300 volts in the alternator - and that voltage goes to the
>> feild. The alternator WILL destroy itself in this case - and it CAN
>> burn.
>>
>> I would definitely want the alternator modified so the feild is
>> externally fed ONLY.
>
> And how would you go about doing that?
>
> Bob
Take the alternator apart--remove the regulator..the "field" in an
alternator is the ROTOR--which is energized by the brushes.
one brush goes to the regulator--extend it to the outside.--the other
brush is usually grounded or tied to the stator---
choose a regulator to suit--A Ford works on most---but my little
nippondenso had to have a Mopar pickup regulator--You may have to get a
rebuilder to help you.--Jerry

[[email protected]]

On Jun 9, 8:01*pm, wrote:
> On Jun 9, 9:57*pm, wrote:
>
>
>
> > On Mon, 8 Jun 2009 21:36:59 -0700 (PDT),
> > wrote:
>
> > >On Jun 8, 2:43 pm, Anthony W > wrote:
> > >> It would be impossible for the alternator to continue to make power if
> > >> the wire to it were disconnected. *There would be no power to the field
> > >> coil and therefor no output.
>
> > >In an alternator with an integral regulator the output feeds the
> > >regulator via an internal connection and therefore the field. It'll
> > >still produce. But if the output to the aircraft is run to a pullable
> > >breaker on the panel, it can be shut off and the alternator can go
> > >play with itself. Only problem is that the output line to the breaker
> > >is still live and can cause trouble in the event of a fire or forced
> > >landing.
>
> > >Dan
>
> > Not the only problem. If the alternator full fields offline voltage
> > can excede 300 volts in the alternator - and that voltage goes to the
> > feild. The alternator WILL destroy itself in this case - and it CAN
> > burn.
>
> > I would definitely want the alternator modified so the feild is
> > externally fed ONLY.
>
> And how would you go about doing that?
>
> Bob

http://www.aeroelectric.com/articles/Nipon-Denso_Alternator_Mod.pdf