Re: Stus-List Relocating the Yanmar key now alternator..

[Dreuge via CnC-List]

If your alternator is not working then you should simple get an alternator 
buzzer alarm.  

This assumes your alternator alarm is working.  When you turn your key on to 
provide power before actually cranking the engine the engine, you should hear 
the buzzer and see possible two lights on.  If you don’t have lights, you can 
disconnect the wire on the engine oil pressure switch.  The pressure switch 
provide alarm ground when there is no(or low) pressure.  Unplug this wire and 
keep it from grounding against the engine block and turn the key on, if you get 
a buzzer then the alternator alarm is working.

Some of the confusion regarding killing or not killing an alternator may likely 
stems to the the type of alternator and how it’s connected.  Most Yanmars come 
with internally regulated Hitachi alternators.  Maine Sail called these 
alternators “ dumber than a pound of beetle poop”.  

My old C 29 had the standard 35A Hitachi.  The key switch would only provide 
12V power to a line through an alternator alarm buzzer then to the alternators 
“lamp” connection.  When the alternator was not spinning, the “lamp” connection 
provided the ground for the buzzer to alarm.  When the alternator was spinning 
and working, it provided 14V at the “Lamp” connector and since it was also 
providing 14V to the battery, the alarm buzzer saw 14V before and after (i.e. 
zero volt difference) and stopped buzzing.  The alternator also had a 
connection (top of T-connector) for the battery sensing used by the internal 
regulator. In this case, the sense was connected via a short loop to the 
battery connection.   So for this arrangement, I would guess that shutting off 
the key switch would not harm the alternator.  And I know from experience this 
to be the case.

I have heard that some old internal regulated alternators do not have a sense 
connection but rather likely use the lamp connection for sensing.  Or maybe 
even some sense connections are connected to the a key powered switch.  In 
these cases, I could see how an alternator could be harmed by a sudden 
disconnect of the sense voltage.


-
Paul E.
1981 C 38 Landfall 
S/V Johanna Rose
Carrabelle, FL

http://svjohannarose.blogspot.com/

> On Jul 20, 2016, at 12:00 PM, cnc-list-requ...@cnc-list.com wrote:
> 
> Date: Wed, 20 Jul 2016 08:54:27 -0600
> From: Lorne Serpa <lorne.se...@gmail.com <mailto:lorne.se...@gmail.com>>
> To: cnc-list@cnc-list.com <mailto:cnc-list@cnc-list.com>
> Subject: Re: Stus-List Relocating the Yanmar key now alternator..
> Message-ID:
>   

Re: Stus-List Relocating the Yanmar key now alternator..

[Josh Muckley via CnC-List]

It is hard to say for sure what your regulator is going to control voltage
at and without know what type of batteries you have it is hard to know what
voltage it should be.  Normal car alternators control at about 14.4v.  A
lead-acid battery is considered to be fully charged when the resting
voltage is at 12.7v... But that is after it has set for a while or once the
the "overcharge" has been removed.

You most likely did no damage if the alternator is still putting out a
charge and 13.5v is definitely a charge.

Josh Muckley
S/V Sea Hawk
1989 C 37+
Solomons, MD
On Jul 20, 2016 10:55 AM, "Lorne Serpa via CnC-List" <cnc-list@cnc-list.com>
wrote:

> Hum,  I.  New to this boat and boats with diesel engines.  Numerous times
> past couple weeks have turned key off without killing the engine.  I have a
> 20gm. How do I know if I did damage? Check battery voltage while engine is
> running? Should be 13.5 or so?
>
> Lorne Serpa
> C 30MKII 1988
> Friendship,  MD
> On Jul 20, 2016 12:50 AM, "Leslie Paal via CnC-List" <
> cnc-list@cnc-list.com> wrote:
>
>> Small correction:
>> "The sudden high
>>  current overheats the diodes and they fail open"
>> When the battery is disconnected while the alternator is charging the
>> existing field current will generate a high voltage spike that exceeds the
>> reverse voltage breakdown value.  Normal diodes are rated for 60-100V
>> reverse voltage.  The spike can be lot more; depending how high was the
>> charging current (more>higher).  The P/N junction will punch through, the
>> resulting localized current can make it open or short.
>>
>> Overloading forward (normal direction) current will heat the chip and the
>> carefully placed 'impurities' will migrate and make the diode a little or
>> lot leaky.  Unless you fuse the internal connection, the open.
>>
>> Leslie.
>> Phoenix C 1983
>>
>> 
>> On Tue, 7/19/16, Josh Muckley via CnC-List <cnc-list@cnc-list.com> wrote:
>>
>>  Subject: Re: Stus-List Relocating the Yanmar key now alternator..
>>  To: "C List" <cnc-list@cnc-list.com>
>>  Cc: "Josh Muckley" <muckl...@gmail.com>
>>  Date: Tuesday, July 19, 2016, 9:31 AM
>>
>>  I have heard
>>  all of this before and am still electrically confused.  I
>>  have a few theories but no proof.  In the face of my
>>  theories is the fact that it is not consistently
>>  repeatable.  So here goes.
>>  Turn the battery off while running and the
>>  alternator suddenly goes to full output kinda like shifting
>>  to 1st while going 70mph.  I get that.  The sudden high
>>  current overheats the diodes and they fail open.
>>  Turn the key off while running and one of two
>>  things happens.  1st option is that nothing about the
>>  alternator is wired to the ignition and nothing happens.  I
>>
>> ___
>>
>> This list is supported by the generous donations of our members. If you
>> like what we do, please help us pay for our costs by donating. All
>> Contributions are greatly appreciated!
>>
>
> ___
>
> This list is supported by the generous donations of our members. If you
> like what we do, please help us pay for our costs by donating. All
> Contributions are greatly appreciated!
>
>
___

This list is supported by the generous donations of our members. If you like 
what we do, please help us pay for our costs by donating. All Contributions are 
greatly appreciated!

Stus-List Relocating the Yanmar key now alternator..

[Jean-Francois J Rivard via CnC-List]

Hi Lorne, 

If your charging warning light is not "on" constantly, you should be OK. 

It appears the  2GM's are not as likely to be  affected. 

Good Luck, 

Francois Rivard
1990 34+ "Take five"
Lake Lanier, GA

 



Date: Wed, 20 Jul 2016 08:29:47 -0600
From: Message: 2
Date: Wed, 20 Jul 2016 08:54:27 -0600
From: Lorne Serpa <lorne.se...@gmail.com>
To: cnc-list@cnc-list.com
Subject: Re: Stus-List Relocating the Yanmar key now alternator..
Message-ID:
 

Re: Stus-List Relocating the Yanmar key now alternator..

[Lorne Serpa via CnC-List]

Hum,  I.  New to this boat and boats with diesel engines.  Numerous times
past couple weeks have turned key off without killing the engine.  I have a
20gm. How do I know if I did damage? Check battery voltage while engine is
running? Should be 13.5 or so?

Lorne Serpa
C 30MKII 1988
Friendship,  MD
On Jul 20, 2016 12:50 AM, "Leslie Paal via CnC-List" <cnc-list@cnc-list.com>
wrote:

> Small correction:
> "The sudden high
>  current overheats the diodes and they fail open"
> When the battery is disconnected while the alternator is charging the
> existing field current will generate a high voltage spike that exceeds the
> reverse voltage breakdown value.  Normal diodes are rated for 60-100V
> reverse voltage.  The spike can be lot more; depending how high was the
> charging current (more>higher).  The P/N junction will punch through, the
> resulting localized current can make it open or short.
>
> Overloading forward (normal direction) current will heat the chip and the
> carefully placed 'impurities' will migrate and make the diode a little or
> lot leaky.  Unless you fuse the internal connection, the open.
>
> Leslie.
> Phoenix C 1983
>
> 
> On Tue, 7/19/16, Josh Muckley via CnC-List <cnc-list@cnc-list.com> wrote:
>
>  Subject: Re: Stus-List Relocating the Yanmar key now alternator..
>  To: "C List" <cnc-list@cnc-list.com>
>  Cc: "Josh Muckley" <muckl...@gmail.com>
>  Date: Tuesday, July 19, 2016, 9:31 AM
>
>  I have heard
>  all of this before and am still electrically confused.  I
>  have a few theories but no proof.  In the face of my
>  theories is the fact that it is not consistently
>  repeatable.  So here goes.
>  Turn the battery off while running and the
>  alternator suddenly goes to full output kinda like shifting
>  to 1st while going 70mph.  I get that.  The sudden high
>  current overheats the diodes and they fail open.
>  Turn the key off while running and one of two
>  things happens.  1st option is that nothing about the
>  alternator is wired to the ignition and nothing happens.  I
>
> ___
>
> This list is supported by the generous donations of our members. If you
> like what we do, please help us pay for our costs by donating. All
> Contributions are greatly appreciated!
>
___

This list is supported by the generous donations of our members. If you like 
what we do, please help us pay for our costs by donating. All Contributions are 
greatly appreciated!

Re: Stus-List Relocating the Yanmar key now alternator..

[Leslie Paal via CnC-List]

Small correction:
"The sudden high
 current overheats the diodes and they fail open"
When the battery is disconnected while the alternator is charging the existing 
field current will generate a high voltage spike that exceeds the reverse 
voltage breakdown value.  Normal diodes are rated for 60-100V reverse voltage.  
The spike can be lot more; depending how high was the charging current 
(more>higher).  The P/N junction will punch through, the resulting localized 
current can make it open or short.

Overloading forward (normal direction) current will heat the chip and the 
carefully placed 'impurities' will migrate and make the diode a little or lot 
leaky.  Unless you fuse the internal connection, the open.

Leslie.
Phoenix C 1983


On Tue, 7/19/16, Josh Muckley via CnC-List <cnc-list@cnc-list.com> wrote:

 Subject: Re: Stus-List Relocating the Yanmar key now alternator..
 To: "C List" <cnc-list@cnc-list.com>
 Cc: "Josh Muckley" <muckl...@gmail.com>
 Date: Tuesday, July 19, 2016, 9:31 AM
 
 I have heard
 all of this before and am still electrically confused.  I
 have a few theories but no proof.  In the face of my
 theories is the fact that it is not consistently
 repeatable.  So here goes.
 Turn the battery off while running and the
 alternator suddenly goes to full output kinda like shifting
 to 1st while going 70mph.  I get that.  The sudden high
 current overheats the diodes and they fail open.
 Turn the key off while running and one of two
 things happens.  1st option is that nothing about the
 alternator is wired to the ignition and nothing happens.  I

___

This list is supported by the generous donations of our members. If you like 
what we do, please help us pay for our costs by donating. All Contributions are 
greatly appreciated!

Stus-List Relocating the Yanmar key now alternator..

[Syerdave--- via CnC-List]

Rather than filling pages and inboxes, Am assuming the subject is not of 
interest to most in this level of detail.   I Have replied in more detail, and 
with a hypothesis, to josh and JF off list...(who may not be all that 
interested either... Lol.)
 Again, this site is well worth exploring on this subject.  The author has 
provided very clear explanations of alternator theory, in two levels of detail. 
 
http://www.pirate4x4.com/tech/billavista/Wiring/Part2/

Dave

Message: 1
Date: Tue, 19 Jul 2016 16:31:09 +
From: Josh Muckley 
To: "C List" 
Subject: Re: 
Message-ID:
   
Content-Type: text/plain; charset="utf-8"

I have heard all of this before and am still electrically confused.  I have
a few theories but no proof.  In the face of my theories is the fact that
it is not consistently repeatable.  So here goes.

Turn the battery off while running and the alternator suddenly goes to full
output kinda like shifting to 1st while going 70mph.  I get that.  The
sudden high current overheats the diodes and they fail open.

Turn the key off while running and one of two things happens.  1st option
is that nothing about the alternator is wired to the ignition and nothing
happens.  I believe that this is the situation with the ignition system in
the video I posted earlier in this thread.  As mentioned by others the
battery and voltage sensing lines are basically directly connected to the
battery so turning the key on or off doesn't affect anything.  I also think
this is the slow and very low battery drain which someone else mentioned.

The 2nd option is that the ignition is attached to the sensing circuit as
in the schematic.  The switch turns on and off the regulator and
subsequently the rotor field.  This would apply to alternators with either
the internal or external regulator.  As the regulator is turned off this
might be causing a momentary high counter electromotive force or an
unopposed stator current (surge).  Or maybe a sudden full reverse bias
current of the diodes.  This is obviously the confusing part.

I've never figured it out and until someone else explains it I don't plan
to make a habit of turning off the switch or the battery.

Josh Muckley
S/V Sea Hawk
1989 C 37+
Solomons, MD
Couple other data points:
___

This list is supported by the generous donations of our members. If you like 
what we do, please help us pay for our costs by donating. All Contributions are 
greatly appreciated!

Re: Stus-List Relocating the Yanmar key now alternator..

[Jean-Francois J Rivard via CnC-List]

Hi Dave, 


Thanks for the added stuff. 

Actually it seems to explain it all: 

Why some alternators fry and some don't:  The key here is the "Self 
Exciting" part.  The self exciting alternators don't need the ignition 
return side at all.  Basically all your key does is turn-off the 
instrument panel (And annoying buzzer) and disable the starter.  Your 
alternator's function is truly not affected by the key . 

This other site I saw explains that very clearly : 
https://alternatorparts.com/what-is-a-self-exciting-alternator.html


That also explain the runaway voltage situation: It says:  "Remember the 
diagram of the pulsed DC output from the alternator and the fact that the 
battery acts as a large filter or cushion in the system. " so basically 
from looking at the schema you can see that in the non-self exciting 
alternator like mine the ignition  / charging light is connected straight 
into the alternator.  If you switch the battery off while the engine is 
running since it's a diesel it keeps chugging /  the alternator keeps 
producing juice and the voltage regulator will take the brunt of the 
stator's output which causes the voltage spike.. 

Bottom line, it appears the 2QM 2GM engines have self-exciting alternators 
and the 3GM's don't. 


-Francois Rivard
1990 34+ "Take Five"
Lake Lanier, GA





"While this clarifies the role of that supply and why the engine will run 
fine, (and for many of us, without apparent damage) with the key removed.  
(once spinning, the alternator excites itself,)   it does not explain the 
failure experienced by only some of us, or the absence of warning in the 
various factory docs.

Based on my extensive online research ;-)  the failure experienced is as 
if the alternator is seeing no load, (i.e. battery disconnected) or as if 
it is running unregulated, with a fully energized field coil.   I wonder 
if the failing alternators have an issue (i.e. failed regulator?) that is 
hidden by the presence of the independent field current supply, and only 
becomes exposed in its absence" 


Regards



François Rivard
 4111 Northside Pkwy, Nw

Big Data Black Belt
Certified Level 3 IT Specialist Thought Leader

 Atlanta, 30327-3015 USA
IBM Sales & Distribution, Software Sales
 
Mobile:
770-639-0429
 

e-mail:
jfriv...@us.ibm.com
 

 
 




From:   Dave Syer <syerd...@gmail.com>
To: "C Stus List" <cnc-list@cnc-list.com>, Jean-Francois J 
Rivard/Atlanta/IBM@IBMUS
Date:   07/19/2016 01:35 PM
Subject:Re: Stus-List Relocating the Yanmar key now alternator..



There is a great explanation of all this here:

http://www.pirate4x4.com/tech/billavista/Wiring/Part2/

And, to complete your commentary below, a lucid explanation of the role of 
the key switch circuit in our engines.

>>>snip
Field Current Supply
The field current supply is provided from one of two different sources, 
depending on the state of the alternator. When the engine is not running 
and the alternator is not spinning and producing electricity, the field 
current supply comes from the vehicle's battery, via the ignition switch 
and alternator warning lamp (if equipped). We'll go into more detail on 
the warning lamp shortly. The process of supplying battery voltage to 
"kick-start" or "prime" the alternator is known as "exciting" the 
alternator, and the wire that carries the current from the alternator 
warning lamp to the appropriate voltage regulator terminal is known as the 
"exciter" wire. A few special alternators do not have this wire and are 
known as "self-exciting" - we'll cover this in more detail in the wiring 
section.
After the engine is started, and the alternator is generating electricity 
the diode trio feeds the alternator output back to the voltage regulator 
to serve as the field current supply.
Theoretically, once up to speed, the alternator is self sustaining, and 
the car will run without a battery until it is shut off (as long as system 
demand does not exceed alternator output capacity).  However - you should 
never disconnect the battery in a running vehicle as doing so can cause 
voltage surges that can damage not only the voltage regulator, but also 
other on-board electrical equipment - particularly computer-controlled 
devices. Remember the diagram of the pulsed DC output from the alternator 
and the fact that the battery acts as a large filter or cushion in the 
system. 
Note that the field current is much smaller than the output current 
produced in the stator windings. For example, to produce 70 amperes of DC, 
the field current required will be less than 2 amperes.
>>>snip

While this clarifies the role of that supply and why the engine will run 
fine, (and for many of us, without apparent damage) with the key removed.  
(once spinning, the alternator excites itself,)   it does not explain the 
failure experienced by only s

Re: Stus-List Relocating the Yanmar key now alternator..

[Dave Syer via CnC-List]

There is a great explanation of all this here:

http://www.pirate4x4.com/tech/billavista/Wiring/Part2/

And, to complete your commentary below, a lucid explanation of the role of
the key switch circuit in our engines.

>>>snip
Field Current Supply

The field current supply is provided from one of two different sources,
depending on the state of the alternator. When the engine is not running
and the alternator is not spinning and producing electricity, the field
current supply comes from the vehicle's battery, via the ignition switch
and alternator warning lamp (if equipped). We'll go into more detail on the
warning lamp shortly. The process of supplying battery voltage to
"kick-start" or "prime" the alternator is known as "exciting" the
alternator, and the wire that carries the current from the alternator
warning lamp to the appropriate voltage regulator terminal is known as the
"exciter" wire. A few special alternators do not have this wire and are
known as "self-exciting" - we'll cover this in more detail in the wiring
section.

After the engine is started, and the alternator is generating electricity
the diode trio feeds the alternator output back to the voltage regulator to
serve as the field current supply.

Theoretically, once up to speed, the alternator is self sustaining, and the
car will run without a battery until it is shut off (as long as system
demand does not exceed alternator output capacity).  However - you should
never disconnect the battery in a running vehicle as doing so can cause
voltage surges that can damage not only the voltage regulator, but also
other on-board electrical equipment - particularly computer-controlled
devices. Remember the diagram of the pulsed DC output from the alternator
and the fact that the battery acts as a large filter or cushion in the
system.

Note that the field current is much smaller than the output current
produced in the stator windings. For example, to produce 70 amperes of DC,
the field current required will be less than 2 amperes.
>>>snip

While this clarifies the role of that supply and why the engine will run
fine, (and for many of us, without apparent damage) with the key removed.
(once spinning, the alternator excites itself,)   it does not explain the
failure experienced by only some of us, or the absence of warning in the
various factory docs.

Based on my extensive online research ;-)  the failure experienced is as if
the alternator is seeing no load, (i.e. battery disconnected) or as if it
is running unregulated, with a fully energized field coil.   I wonder if
the failing alternators have an issue (i.e. failed regulator?) that is
hidden by the presence of the independent field current supply, and only
becomes exposed in its absence?

Dave




Message: 2
Date: Tue, 19 Jul 2016 09:21:52 -0400
From: "Jean-Francois J Rivard" <jfriv...@us.ibm.com>
To: "syerd...@gmail.com" <syerd...@gmail.com>
Cc: cnc-list@cnc-list.com
Subject: Re: Stus-List Relocating the Yanmar key now alternator..
Message-ID:
<
of4343dba2.fa97e163-on00257ff5.004567a8-85257ff5.00496...@notes.na.collabserv.com
>

Content-Type: text/plain; charset="us-ascii"

Hi Dave,


Here's how I understood the whole thing.  An alternator's design is
basically the reverse of a regular DC motor with an added twist..

On a regular DC motor the windings (Electro magnets) are on the spinning
armature and there are permanent magnets attached to the housing. You add
voltage to it:  The windings are energized, they produce a magnetic force
opposite to the permanent magnet on the housing, the motor spins. The more
voltage, the stronger the electro magnet on the armature becomes, the
faster it spins


On an alternator, the windings are on the housing (Stator) and the magnets
are spinning with the shaft (Rotor).
You spin the alternator, the magnets fields excite the windings, A/C
electricity is produced.
The alternator's added twist is that the magnets are not permanent, they
are electro-magnets with their own winding.  The genius here is that it
makes the magnets adjustable where their strength (And the Alternator's
output) can be controlled by varying the voltage applied to them while
still being driven at the same RPM..  Voila :-)


The alternator I burned was most assuredly the original Yanmar unit.. It
had the funky looking fan, was stamped 'Yanmar", and was painted the same
color as the rest of the engine.  I guess the one on your 2GM is somehow
different than what was on my 3GM..
___

This list is supported by the generous donations of our members. If you like 
what we do, please help us pay for our costs by donating. All Contributions are 
greatly appreciated!

Re: Stus-List Relocating the Yanmar key now alternator..

[Josh Muckley via CnC-List]

I have heard all of this before and am still electrically confused.  I have
a few theories but no proof.  In the face of my theories is the fact that
it is not consistently repeatable.  So here goes.

Turn the battery off while running and the alternator suddenly goes to full
output kinda like shifting to 1st while going 70mph.  I get that.  The
sudden high current overheats the diodes and they fail open.

Turn the key off while running and one of two things happens.  1st option
is that nothing about the alternator is wired to the ignition and nothing
happens.  I believe that this is the situation with the ignition system in
the video I posted earlier in this thread.  As mentioned by others the
battery and voltage sensing lines are basically directly connected to the
battery so turning the key on or off doesn't affect anything.  I also think
this is the slow and very low battery drain which someone else mentioned.

The 2nd option is that the ignition is attached to the sensing circuit as
in the schematic.  The switch turns on and off the regulator and
subsequently the rotor field.  This would apply to alternators with either
the internal or external regulator.  As the regulator is turned off this
might be causing a momentary high counter electromotive force or an
unopposed stator current (surge).  Or maybe a sudden full reverse bias
current of the diodes.  This is obviously the confusing part.

I've never figured it out and until someone else explains it I don't plan
to make a habit of turning off the switch or the battery.

Josh Muckley
S/V Sea Hawk
1989 C 37+
Solomons, MD
Couple other data points:

   - The diesel mechanic gave me a huge DUH ! when I explained what had
   happened.. He said, you just learned the hard way that you should never
   turn off the ignition key on a diesel while it's running. What happened was
   punishment for my brain fart.. The guy fixes diesels for a living
   - The alternator shop I talked to said the exact same thing. Burned
   diodes blah blah, happens all the time to new diesel owners..
   -


Francois Rivard
1990 34+ "Take Five"
lake Lanier, GA

___

This list is supported by the generous donations of our members. If you
like what we do, please help us pay for our costs by donating. All
Contributions are greatly appreciated!
___

This list is supported by the generous donations of our members. If you like 
what we do, please help us pay for our costs by donating. All Contributions are 
greatly appreciated!

Re: Stus-List Relocating the Yanmar key now alternator..

[Gary Nylander via CnC-List]

I guess I didn't know what I was doing wrong - I had an overheating problem
which was intermittent. The annoying little buzzer would blast away but I
still had water flowing through the system (I guess not quite enough to
satisfy the sensor). After more than a few minutes of this, I turned the key
(or in my case the pull switch off ) which turned off the buzzer and tach
and light. Motor still ran alternator seemed to be putting out - still is
about three years later. I guess I was lucky - still have same alternator
and have fixed the blockage in the water system - a small piece of an
impeller which was petrified and stuck near one of the zincs - and which
must have been there since before 1994 when I bought the boat - all the
impellers I have changed over the years came out in one piece. Now have more
flow and no noise. 1980 Yanmar 2QM15.

 

Gary

30-1

 

 

 

From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of
Jean-Francois J Rivard via CnC-List
Sent: Tuesday, July 19, 2016 9:22 AM
To: syerd...@gmail.com
Cc: Jean-Francois J Rivard <jfriv...@us.ibm.com>; cnc-list@cnc-list.com
Subject: Re: Stus-List Relocating the Yanmar key now alternator..

 

Hi Dave, 


Here's how I understood the whole thing.  An alternator's design is
basically the reverse of a regular DC motor with an added twist.. 

*   On a regular DC motor the windings (Electro magnets) are on the
spinning armature and there are permanent magnets attached to the housing.
You add voltage to it:  The windings are energized, they produce a magnetic
force opposite to the permanent magnet on the housing, the motor spins. The
more voltage, the stronger the electro magnet on the armature becomes, the
faster it spins
*

*   On an alternator, the windings are on the housing (Stator) and the
magnets are spinning with the shaft (Rotor). 
*   You spin the alternator, the magnets fields excite the windings, A/C
electricity is produced. 
*   The alternator's added twist is that the magnets are not permanent,
they are electro-magnets with their own winding.  The genius here is that it
makes the magnets adjustable where their strength (And the Alternator's
output) can be controlled by varying the voltage applied to them while still
being driven at the same RPM..  Voila :-) 


 
The alternator I burned was most assuredly the original Yanmar unit.. It had
the funky looking fan, was stamped 'Yanmar", and was painted the same color
as the rest of the engine.  I guess the one on your 2GM is somehow different
than what was on my 3GM.. 


-Francois
1990 34+ "Take Five"
Lake Lanier, GA





From:"syerd...@gmail.com <mailto:syerd...@gmail.com> "
<syerd...@gmail.com <mailto:syerd...@gmail.com> >
To:Jean-Francois J Rivard/Atlanta/IBM@IBMUS
Cc:cnc-list@cnc-list.com <mailto:cnc-list@cnc-list.com> 
Date:07/19/2016 08:14 AM
Subject:Re: Relocating the Yanmar key now alternator..

  _  




Thanks JF.

An interesting  read here.  

http://www.autoshop101.com/forms/alt_bwoh.pdf

A decent corrected alternator diagram here.  Post #15

http://www.ybw.com/forums/showthread.php?224370-What-s-the-R-connection-for-
on-a-Yanmar-Hitachi-alternator/page2

So, if I understand correctly the key switch energizes the starting circuit,
the warning indicators and provides a reference battery voltage to the
voltage regulator, which regulates the voltage to the field coil and thereby
the alternator output.
More study required to truly grasp the theory, but am still grappling with
why "no key/blown fuse = alternator destruction", and why some have had
alternators fail and some did not.  Also, keyless operation is not discussed
(that I could find) in the owners manual or the shop manual, which seems
strange.
Is it possible that OE Yanmar alternators are of a design that incorporates
safeguards appropriate to this situation, and that the failed alternators
are of a different type?










On Jul 18, 2016, at 1:25 PM, Jean-Francois J Rivard <jfriv...@us.ibm.com
<mailto:jfriv...@us.ibm.com> > wrote:

Hi Dave, 

It's possible your alternator is internally wired differently. As for the
rest of us (again, what I was told) the diodes are supposedly there meant to
both turn the a/c current into dc for use by the batteries and act fuse-like
to prevent the possibility some kind of much worse (Overheat / fire perhaps?
) alternator self destruction. All I knew at the time was for 78 bucks and
45 or so minutes of wrenching I could make it all good again and have the
peace of mind associated with replacing a 20 year old alternator with a
brand new unit. 

Now that I'm looking into it that appears the catastrophic failure would to
be related to the field coils which are energized as the alternator turns
and their voltage is regulated by the battery / voltage regulator.
Apparently, if left unchecked (With a disconnected battery, open "ig

Stus-List Relocating the Yanmar key now alternator..

[Jean-Francois J Rivard via CnC-List]

Couple other data points: 

The diesel mechanic gave me a huge DUH ! when I explained what had 
happened.. He said, you just learned the hard way that you should never 
turn off the ignition key on a diesel while it's running. What happened 
was punishment for my brain fart.. The guy fixes diesels for a living
The alternator shop I talked to said the exact same thing. Burned diodes 
blah blah, happens all the time to new diesel owners.. 


Francois Rivard
1990 34+ "Take Five"
lake Lanier, GA

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Re: Stus-List Relocating the Yanmar key now alternator..

[Jean-Francois J Rivard via CnC-List]

Hi Dave, 


Here's how I understood the whole thing.  An alternator's design is 
basically the reverse of a regular DC motor with an added twist.. 

On a regular DC motor the windings (Electro magnets) are on the spinning 
armature and there are permanent magnets attached to the housing. You add 
voltage to it:  The windings are energized, they produce a magnetic force 
opposite to the permanent magnet on the housing, the motor spins. The more 
voltage, the stronger the electro magnet on the armature becomes, the 
faster it spins


On an alternator, the windings are on the housing (Stator) and the magnets 
are spinning with the shaft (Rotor). 
You spin the alternator, the magnets fields excite the windings, A/C 
electricity is produced. 
The alternator's added twist is that the magnets are not permanent, they 
are electro-magnets with their own winding.  The genius here is that it 
makes the magnets adjustable where their strength (And the Alternator's 
output) can be controlled by varying the voltage applied to them while 
still being driven at the same RPM..  Voila :-) 

 
The alternator I burned was most assuredly the original Yanmar unit.. It 
had the funky looking fan, was stamped 'Yanmar", and was painted the same 
color as the rest of the engine.  I guess the one on your 2GM is somehow 
different than what was on my 3GM.. 


-Francois
1990 34+ "Take Five"
Lake Lanier, GA





From:   "syerd...@gmail.com" <syerd...@gmail.com>
To: Jean-Francois J Rivard/Atlanta/IBM@IBMUS
Cc: cnc-list@cnc-list.com
Date:   07/19/2016 08:14 AM
Subject:Re: Relocating the Yanmar key now alternator..



Thanks JF.

An interesting  read here. 

http://www.autoshop101.com/forms/alt_bwoh.pdf

A decent corrected alternator diagram here.  Post #15

http://www.ybw.com/forums/showthread.php?224370-What-s-the-R-connection-for-on-a-Yanmar-Hitachi-alternator/page2

So, if I understand correctly the key switch energizes the starting 
circuit, the warning indicators and provides a reference battery voltage 
to the voltage regulator, which regulates the voltage to the field coil 
and thereby the alternator output.
More study required to truly grasp the theory, but am still grappling with 
why "no key/blown fuse = alternator destruction", and why some have had 
alternators fail and some did not.  Also, keyless operation is not 
discussed (that I could find) in the owners manual or the shop manual, 
which seems strange.
Is it possible that OE Yanmar alternators are of a design that 
incorporates safeguards appropriate to this situation, and that the failed 
alternators are of a different type?










On Jul 18, 2016, at 1:25 PM, Jean-Francois J Rivard <jfriv...@us.ibm.com> 
wrote:

Hi Dave, 

It's possible your alternator is internally wired differently. As for the 
rest of us (again, what I was told) the diodes are supposedly there meant 
to both turn the a/c current into dc for use by the batteries and act 
fuse-like to prevent the possibility some kind of much worse (Overheat / 
fire perhaps? ) alternator self destruction. All I knew at the time was 
for 78 bucks and 45 or so minutes of wrenching I could make it all good 
again and have the peace of mind associated with replacing a 20 year old 
alternator with a brand new unit. 

Now that I'm looking into it that appears the catastrophic failure would 
to be related to the field coils which are energized as the alternator 
turns and their voltage is regulated by the battery / voltage regulator. 
Apparently, if left unchecked (With a disconnected battery, open 
"ignition" circuit) the output voltage could go to a couple hundred volts 
which could potentially make the regulator circuitry immolate itself or 
something to that effect. With the typical setup the diodes burn-out first 
and prevent catastrophic damage.  

See here for more details:  http://www.pangolin.co.nz/node/16


-Francois Rivard
1990 34+ "Take Five"
Lake Lanier, GA


 

Message: 2
Date: Mon, 18 Jul 2016 08:38:01 -0400
From: Dave Syer <syerd...@gmail.com>
To: "C Stus List" <cnc-list@cnc-list.com>
Subject: Stus-List  Relocating the Yanmar key now alternator..
Message-ID:
<
CAD7ywJNLTLNEHS97dz1oBPaK74ymNc-TLCLL=zsojmhkart...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Interesting discussion.   So, I have run my 1985 2gm Yanmar briefly with
the key removed and no apparent harm was done.  The manual does say never
to run it with the battery disconnected.

Now, when I check the schematic, (and my engine) there is a 30A tubular
fuse in series with the key switch.   Therefore a blown fuse = an open key
switch, and would cause the same damage to the alternator.   This does not
make a lot of sense to me. Other than adequate knowledge, am I missing
something?   See below.





___

This list is supported by the generous donations

Re: Stus-List Relocating the Yanmar key now alternator..

[Syerdave--- via CnC-List]

Thanks JF.

An interesting  read here.  

http://www.autoshop101.com/forms/alt_bwoh.pdf

A decent corrected alternator diagram here.  Post #15

http://www.ybw.com/forums/showthread.php?224370-What-s-the-R-connection-for-on-a-Yanmar-Hitachi-alternator/page2

So, if I understand correctly the key switch energizes the starting circuit, 
the warning indicators and provides a reference battery voltage to the voltage 
regulator, which regulates the voltage to the field coil and thereby the 
alternator output.
More study required to truly grasp the theory, but am still grappling with why 
"no key/blown fuse = alternator destruction", and why some have had alternators 
fail and some did not.  Also, keyless operation is not discussed (that I could 
find) in the owners manual or the shop manual, which seems strange.
Is it possible that OE Yanmar alternators are of a design that incorporates 
safeguards appropriate to this situation, and that the failed alternators are 
of a different type?










> On Jul 18, 2016, at 1:25 PM, Jean-Francois J Rivard <jfriv...@us.ibm.com> 
> wrote:
> 
> Hi Dave, 
> 
> It's possible your alternator is internally wired differently. As for the 
> rest of us (again, what I was told) the diodes are supposedly there meant to 
> both turn the a/c current into dc for use by the batteries and act fuse-like 
> to prevent the possibility some kind of much worse (Overheat / fire perhaps? 
> ) alternator self destruction. All I knew at the time was for 78 bucks and 45 
> or so minutes of wrenching I could make it all good again and have the peace 
> of mind associated with replacing a 20 year old alternator with a brand new 
> unit. 
> 
> Now that I'm looking into it that appears the catastrophic failure would to 
> be related to the field coils which are energized as the alternator turns and 
> their voltage is regulated by the battery / voltage regulator.  Apparently, 
> if left unchecked (With a disconnected battery, open "ignition" circuit) the 
> output voltage could go to a couple hundred volts which could potentially 
> make the regulator circuitry immolate itself or something to that effect. 
> With the typical setup the diodes burn-out first and prevent catastrophic 
> damage.  
> 
> See here for more details:  http://www.pangolin.co.nz/node/16
> 
> 
> -Francois Rivard
> 1990 34+ "Take Five"
> Lake Lanier, GA
> 
> 
>  
> 
> Message: 2
> Date: Mon, 18 Jul 2016 08:38:01 -0400
> From: Dave Syer <syerd...@gmail.com>
> To: "C Stus List" <cnc-list@cnc-list.com>
> Subject: Stus-List  Relocating the Yanmar key now alternator..
> Message-ID:
> 
> 

Re: Stus-List Relocating the Yanmar key now alternator..

[Marek Dziedzic via CnC-List]

The worst part is that the test is potentially destructive. If you turn the 
ignition off and nothing happens, you know that you can do that. On the other 
hand, if you do that and you fry the diodes, you know that you shouldn't, but 
you also need to replace the alternator. And trying it on someone else's boat 
is inconclusive.
Marek


Sent from my Bell Samsung device over Canada's largest network.

 Original message 
From: Jean-Francois J Rivard via CnC-List 
<cnc-list@cnc-list.com> Date: 7/18/16  13:27  (GMT-05:00) 
To: cnc-list@cnc-list.com Cc: Jean-Francois J Rivard 
<jfriv...@us.ibm.com>, syerd...@gmail.com Subject: Stus-List 
Relocating the Yanmar key now alternator.. 

Hi Dave,

It's possible your alternator is internally wired differently. As for the
rest of us (again, what I was told) the diodes are supposedly there meant
to both turn the a/c current into dc for use by the batteries and act
fuse-like to prevent the possibility some kind of much worse (Overheat /
fire perhaps? ) alternator self destruction. All I knew at the time was
for 78 bucks and 45 or so minutes of wrenching I could make it all good
again and have the peace of mind associated with replacing a 20 year old
alternator with a brand new unit.

Now that I'm looking into it that appears the catastrophic failure would
to be related to the field coils which are energized as the alternator
turns and their voltage is regulated by the battery / voltage regulator.
Apparently, if left unchecked (With a disconnected battery, open
"ignition" circuit) the output voltage could go to a couple hundred volts
which could potentially make the regulator circuitry immolate itself or
something to that effect. With the typical setup the diodes burn-out first
and prevent catastrophic damage.

See here for more details:  http://www.pangolin.co.nz/node/16


-Francois Rivard
1990 34+ "Take Five"
Lake Lanier, GA




Message: 2
Date: Mon, 18 Jul 2016 08:38:01 -0400
From: Dave Syer <syerd...@gmail.com>
To: "C Stus List" <cnc-list@cnc-list.com>
Subject: Stus-List  Relocating the Yanmar key now alternator..
Message-ID:
 

Stus-List Relocating the Yanmar key now alternator..

[Jean-Francois J Rivard via CnC-List]

Hi Dave, 

It's possible your alternator is internally wired differently. As for the 
rest of us (again, what I was told) the diodes are supposedly there meant 
to both turn the a/c current into dc for use by the batteries and act 
fuse-like to prevent the possibility some kind of much worse (Overheat / 
fire perhaps? ) alternator self destruction. All I knew at the time was 
for 78 bucks and 45 or so minutes of wrenching I could make it all good 
again and have the peace of mind associated with replacing a 20 year old 
alternator with a brand new unit. 

Now that I'm looking into it that appears the catastrophic failure would 
to be related to the field coils which are energized as the alternator 
turns and their voltage is regulated by the battery / voltage regulator. 
Apparently, if left unchecked (With a disconnected battery, open 
"ignition" circuit) the output voltage could go to a couple hundred volts 
which could potentially make the regulator circuitry immolate itself or 
something to that effect. With the typical setup the diodes burn-out first 
and prevent catastrophic damage. 

See here for more details:  http://www.pangolin.co.nz/node/16


-Francois Rivard
1990 34+ "Take Five"
Lake Lanier, GA


 

Message: 2
Date: Mon, 18 Jul 2016 08:38:01 -0400
From: Dave Syer <syerd...@gmail.com>
To: "C Stus List" <cnc-list@cnc-list.com>
Subject: Stus-List  Relocating the Yanmar key now alternator..
Message-ID:
 

Stus-List Relocating the Yanmar key now alternator..

[Dave Syer via CnC-List]

Interesting discussion.   So, I have run my 1985 2gm Yanmar briefly with
the key removed and no apparent harm was done.  The manual does say never
to run it with the battery disconnected.

Now, when I check the schematic, (and my engine) there is a 30A tubular
fuse in series with the key switch.   Therefore a blown fuse = an open key
switch, and would cause the same damage to the alternator.   This does not
make a lot of sense to me. Other than adequate knowledge, am I missing
something?   See below.


http://www.cruisersforum.com/forums/members/31207-albums977-picture16384.png

Dave Syer - '85 33-2






Message: 1
Date: Sun, 17 Jul 2016 22:47:17 -0400
From: "Jean-Francois J Rivard" <jfriv...@us.ibm.com>
To: cnc-list@cnc-list.com
Cc: amira...@bellaliant.net
Subject: Stus-List  Relocating the Yanmar key now alternator..
Message-ID:
<
of7c4f9827.241c1f14-on00257ff4.000d9ee3-85257ff4.000f5...@notes.na.collabserv.com
>

Content-Type: text/plain; charset="us-ascii"

Agreed, I experienced it 1st hand a few months after I had bought the boat
a few years back.. I had a brain fart and turned the key to "off" while
the engine was running. The diodes instantly fried, the alternator was
toast / the charging warning was light on.
___

This list is supported by the generous donations of our members. If you like 
what we do, please help us pay for our costs by donating. All Contributions are 
greatly appreciated!

Stus-List Relocating the Yanmar key now alternator..

[Jean-Francois J Rivard via CnC-List]

Agreed, I experienced it 1st hand a few months after I had bought the boat 
a few years back.. I had a brain fart and turned the key to "off" while 
the engine was running. The diodes instantly fried, the alternator was 
toast / the charging warning was light on. 

Then came the alternator saga: 

(As I was told) Apparently, it's kind of a big deal to replace the diodes. 
On an older alternator you might as well have the whole alternator rebuilt 
or buy a new one.  I found some original Yanmar alternators but they were 
$700.00 (I did not know about Mastry Engine center at the time)Upon 
looking at local rebuild options they were in the $175.00 - 200.00 + 
range.  Upon further research I found an authentic 55 Amp Hitachi 
(Yanmar's OEM)unit with the exact same connections, mounting, and pulley 
for 78 bucks shipped on ebay (Still available). That's the one I got. It 
actually charges the batteries better than the old one.. I guess it was 
the original and probably due for a rebuild anyway. 

Francois Rivard 
1990 34+ "Take Five" 
Lake Lanier, GA

 



Message: 5
Date: Sun, 17 Jul 2016 20:39:46 -0300
From: 
To: 
Subject: Re: Stus-List Relocating the Yanmar key
Message-ID: <9BE1F845BD864E20A70EB87EE8B7BB8A@T60>
Content-Type: text/plain; charset="utf-8"

Didn?t I read somewhere on this group that it was a bad idea to turn off 
the key switch while the engine is running? Can someone confirm/deny this?

Mike Amirault
C Lovely Cruise
SMSC


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This list is supported by the generous donations of our members. If you like 
what we do, please help us pay for our costs by donating. All Contributions are 
greatly appreciated!