Larry, as I get older I find that you're not alone in having "brain cramps". Or
as a friend put it the other day, speaking of me...., "I guess the '60's are
finally catching up with you!"!!! Too true but that's for another discussion
around a couple of cold ones.
To your situation, I've done the same once or twice and, without going to the
trouble of taking it to a local test bench, I noticed the same lack-of-damage.
My gut tells me that in my case and yours, we probably shut down the engine
before any damage was done. In my case it was always a case of "Oh S**t!" and
immediately pulling the fuel cut-off.
In any event, I installed one of those gizmos (Zap Stopper????) for "just in
case" but, naturally, since I installed it a couple of years ago, I haven't
made the same mistake again <g>.
I think that Zap Stopper is less than $20 at Worst Marine and takes about 5
minutes to install. Whether or not it offers true protection, I leave that to
the knowledgeable pundits on the list.
>From my standpoint it came under the category of " 'couldn't hurt".
S
Steve Weinstein
S/V HYDRO-THERAPY
1981 Cherubini Hunter 33
Sailing out of Oyster Bay, NY
All outgoing mail protected by Norton A/V
----- Original Message -----
From: Larry Dill
To: [email protected]
Sent: Wednesday, May 07, 2008 8:35 AM
Subject: Re: [Liveaboard] "Fied" nectin
Lew and Others,
I have been following this thread very closely and do agree with all that
has been written... I do not post much and then there is a question that I
would like to pose to you... I had brain cramp and turned off the batt switch
before turning off the engine, I have a Balmar 200 amp alternator, after I
realized what I had done, I quickly shut down the engine... I then proceeded to
remove the alternator and have it bench tested at the local alternator shop...
Which turned out to be nothing wrong with the alt., now how do you see how this
was the case, that no damage came to the alt.???
TIA
Sea Ya
Larry
S/V Two Step-N
N 40* 53.320'
W 073* 47.122'
----- Original Message ----
From: Lew Hodgett <[EMAIL PROTECTED]>
To: [email protected]
Sent: Wednesday, May 7, 2008 12:23:40 AM
Subject: Re: [Liveaboard] "Fied" nectin
" capteric36" wrote:
> The field connection on a battery switch is
> there to protect the alternator diodes in the
> event that the battery switch gets turned to the
> off' position while the alternator is spinning.
Close, but no cigar.
> If
> there is still field current but no load (battery)
> the output voltage of an alternator will very
> quickly rise high enough to destroy the diodes.
True.
> Thus the field connection in the battery switch is
> designed to open before the battery connection,
> shutting down the alternator. DO NOT rely on this,
> as the time it takes the magnetic field in the
> alternator to collapse may often be enough time to
> destroy the diodes.
True.
Basic rule of the boat battery switch.
If the alternator is rotating, DO NOT TOUCH THE BATTERY SWITCH.
WHY?
The generated alternator voltage that is developed without being
connected to a load (Battery) will generate an inverse voltage that
will destroy the silicon diode bridge.
The above is totally independent of the alternator field circuit.
Turn the battery switch "ON" or "OFF" only when the engine/alternator
is at rest.
The use of the oil pressure switch in the field circuit is used to
reduce the starting torque requirement of the cranking motor.
There is enough residual magnetism in the rotator of the alternator to
generate a limited amount of power at the output terminals, thus the
need to be connected to the battery.
An old trick, if the AC output terminals are available, is to connect
a half wave rectifier bridge to the coil of a relay whose contacts are
in the field circuit.
Thus the cranking motor did not hasve to overcome the alternator
starting torque.
As soon as the engine is cranked over and starts, enough voltage is
generated to close the relay thus applying power to the field circuit
which starts the alternator charging.
No AC terminals available, the oil pressure switch works just fine.
Lew
_______________________________________________
Liveaboard mailing list
[email protected]
To adjust your membership settings over the web
http://www.liveaboardnow.org/mailman/listinfo/liveaboard
To subscribe send an email to [EMAIL PROTECTED]
To unsubscribe send an email to [EMAIL PROTECTED]
The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/
To search the archives
http://www.mail-archive.com/[email protected]
The Mailman Users Guide can be found here
http://www.gnu.org/software/mailman/mailman-member/index.html
------------------------------------------------------------------------------
Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.
------------------------------------------------------------------------------
_______________________________________________
Liveaboard mailing list
[email protected]
To adjust your membership settings over the web
http://www.liveaboardnow.org/mailman/listinfo/liveaboard
To subscribe send an email to [EMAIL PROTECTED]
To unsubscribe send an email to [EMAIL PROTECTED]
The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/
To search the archives
http://www.mail-archive.com/[email protected]
The Mailman Users Guide can be found here
http://www.gnu.org/software/mailman/mailman-member/index.html
_______________________________________________
Liveaboard mailing list
[email protected]
To adjust your membership settings over the web
http://www.liveaboardnow.org/mailman/listinfo/liveaboard
To subscribe send an email to [EMAIL PROTECTED]
To unsubscribe send an email to [EMAIL PROTECTED]
The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/
To search the archives http://www.mail-archive.com/[email protected]
The Mailman Users Guide can be found here
http://www.gnu.org/software/mailman/mailman-member/index.html
