Alternator help ?????

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woodster

woodster

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Sep 15, 2009
6,244
S2 9.2a Fairhope Al
OK i have just installed my type c panel after building an engine harness to my 2gm20f in my 9.2a.....now for the brick wall part of this.....the positive terminal is for the positive side of the starter/battery......the E terminal is for the negative side of the battery.....simple so far .....now there are also 3 spade connectors on the back....one on the upper left side marked N and running vertical ....there are 2 spade connectors on the upper right side running perpendicular to each other ...vertical on bottom and horizontal on top....with no markings ....so my question is what do they hook to......i have a pic at the bottom of the page.....any help would be appreciated....

regards

woody
 

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J

JohnShannon

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Jan 4, 2010
1,037
Farr 30 San Francisco
field windings I would suspect. the field winding is an electromagnet whose strength is controlled by the regulator. this is electromagnet is spun by the motor to create voltage in stator windings.
 
B

bugaloo

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Sep 30, 2010
130
hunter 33 Hunter Morehead city
The top one (-) is labeled R mostly not used sometimes exciter voltage
The lower one (I)is labeled L power to excite alt from alt indicator light
 
woodster

woodster

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Sep 15, 2009
6,244
S2 9.2a Fairhope Al
thanks for the feed back the both of you .....if the R is exciter voltage and you say its not used some times if i hook up R and I and have them reversed will it blow a diode in the alt or will it simply just not work correctly.....

i am hooking up this alt just to get the system 100% on line and will going forward go to a larger alt to satisfy the 270 amp battery bank i am installing on the boat ...i read some where that the rule of thumb for charging AGM Bat's that one needs to divide the amps by 2 and then be able to supply 20% of that for recharge and of course have enough alt to supply that requirement at 80% of the alts ability in order to not over heat the alt ....i think it was in an article that Maine sail contributed in the past about the pit falls of using AGM battries.....

regards

woody
 
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Benny17441

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May 24, 2004
7,213
CC 30 South Florida
We also run a 2GM20F and the little engine seems to be taxed enough with the stock 55A alternator. If you are considering a high output alternator make sure you do your homework. We considered it some time ago and decided not to worsen an already underpowered condition. Sorry it is an h320 with a dry weight of close to 12,000 lbs as delivered.
 
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sailaway78

sailaway78

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May 11, 2005
3,431
Seidelman S37 Slidell, La.
I had one of those

I had one just like that on a 2gm. Had to go to an alternator shop to get the proper plug for it. Has been a while, but if memory serves, the wrong way, and it puts out a constant 16 volts. Check with an alternator shop. I just don't remember which way it goes. The original Hitachi on mine had that same plug, but had a little metal box, with only one wire coming out of it.
 
woodster

woodster

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Sep 15, 2009
6,244
S2 9.2a Fairhope Al
Benny17441 said:
We also run a 2GM20F and the little engine seems to be taxed enough with the stock 55A alternator. If you are considering a high output alternator make sure you do your homework. We considered it some time ago and decided not to worsen an already underpowered condition.
Click to expand
thanks Benny for the heads up ...I had a 30 ft boat that weighs 9400 lbs before any gear is stowed in it..... not sure how big you boat is or how much it weighs ...I am hoping it will do the job but it may not as you say.... up date on my alt ....went to the alt shop to confirm the connections today and see what amp out put it is ...the connections are now imprinted in my worn out brain...the bad news it is an 80 amp unit and it is fry-ed so have to either replace it or repair it so as things go a little difficulty has brought on more needs and fixes :doh:

regards

woody
 
woodster

woodster

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Sep 15, 2009
6,244
S2 9.2a Fairhope Al
sailaway78 said:
I had one just like that on a 2gm. Had to go to an alternator shop to get the proper plug for it. Has been a while, but if memory serves, the wrong way, and it puts out a constant 16 volts. Check with an alternator shop. I just don't remember which way it goes. The original Hitachi on mine had that same plug, but had a little metal box, with only one wire coming out of it.
Click to expand
that is the same thing the alt guy said...if they were reversed it would not be able to tell how much voltage it was putting out and would deliver all it had ....connected in the right order would let it do its job .....

thanks for the feed back


regards

woody
 
sailaway78

sailaway78

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May 11, 2005
3,431
Seidelman S37 Slidell, La.
Wish

Wish I could remember exactly how that thing wires up, but slept too many nites since then. But do remember when figured out it was pretty simple to do. My alternator guy had a plug for it.
 
kloudie1

kloudie1

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Nov 6, 2006
10,216
Hunter 34 Mandeville Louisiana
on the Hitachis, the topmost horizontal one is the "R" terminal which goes to the ignition switch for +12V when the switch is on. The vertical one just below it is the "L" terminal to the charge lamp. The N is probably tachometer output and if you are using the original "tooth counter" tachometer, you can leave it blank.
EDIT: Hope this helps:
 

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sailaway78

sailaway78

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May 11, 2005
3,431
Seidelman S37 Slidell, La.
I think

I think kloudie is dead on. And if memory serves, you have to use the charge light for it to work. But don't bet the farm on that part.
 
woodster

woodster

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Sep 15, 2009
6,244
S2 9.2a Fairhope Al
kloudie1 said:
on the Hitachis, the topmost horizontal one is the "R" terminal which goes to the ignition switch for +12V when the switch is on. The vertical one just below it is the "L" terminal to the charge lamp. The N is probably tachometer output and if you are using the original "tooth counter" tachometer, you can leave it blank.
Click to expand
thanks Kloudie...i have the fly wheel sensor for my tach and intend to use it..... when the yanny tach craps out i will replace it with a wema tach... they will hook up to the sensor or the alt and can be calibrated to with in 3 rpms of correct...and the cool part is they are around $85.00.....hooking it up to the fly wheel sensor would be more accurate that the alt because the belt will loosen up over time and go out of calibration....

regards

woody
 
woodster

woodster

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Sep 15, 2009
6,244
S2 9.2a Fairhope Al
OK day three of this.....have been thinking about the alt size to put on the 2gm20f that is rated from 13 hp all the way to 18 hp the latter being doubtful.....it has been said that a 55 amp alt takes it toll on the power factor of this engine....so if one was to go to an 80 amp alt seems to me it would be even more of The same...but having what i have complicates things as the budget goes..so having said all that when is enough enough would one use what they have or down size to a 55 amp being that the 80 has to be repaired any way or have it repaired and use it for a spare in an emergency and run a 55 alt as the standard .....the banks potential is from 180 amps to 270 amps depending on weather i parallel 2 or 3 bats together ...it would be nice to have the 270 bank (giving 135 amp usable power) but it would be practical to have the 180 amp bank(having 90 amps usable power)....useage of the boat for the first year is planned to be part time maybe 2 weeks out of each month (for educational purposes being that i am a green horn to actual sailing) and hopefully after that it will be full time ...so as a friend of mine from Josey says "Whats a mother to do!"...advice is free as we all know but it does give food for though so chime in and give it some fuel ....

regards

woody
 
Maine Sail

Maine Sail

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Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
woodster said:
OK day three of this.....have been thinking about the alt size to put on the 2gm20f that is rated from 13 hp all the way to 18 hp the latter being doubtful.....it has been said that a 55 amp alt takes it toll on the power factor of this engine....so if one was to go to an 80 amp alt seems to me it would be even more of The same...but having what i have complicates things as the budget goes..so having said all that when is enough enough would one use what they have or down size to a 55 amp being that the 80 has to be repaired any way or have it repaired and use it for a spare in an emergency and run a 55 alt as the standard .....the banks potential is from 180 amps to 270 amps depending on weather i parallel 2 or 3 bats together ...it would be nice to have the 270 bank (giving 135 amp usable power) but it would be practical to have the 180 amp bank(having 90 amps usable power)....useage of the boat for the first year is planned to be part time maybe 2 weeks out of each month (for educational purposes being that i am a green horn to actual sailing) and hopefully after that it will be full time ...so as a friend of mine from Josey says "Whats a mother to do!"...advice is free as we all know but it does give food for though so chime in and give it some fuel ....

regards

woody
Click to expand
Woody,

I have many installations on similar HP engines up to 100A alts with no issues. The issues normally arise when the engine is also over propped.

I would strongly urge you not to stick with an internally regulated Hitachi. They "self protect" by reducing charging voltage through thermal compensation inside the "dumb regulator". Reducing the voltage reduces the current to the batteries and leads to chronic undercharging when the alt heats up.

With an external regulator such as a Balmar they can be wired for many scenarios and also current limited too. You can also wire in a switch to the engine panel that reduces alt output by 50% for when you need more power.

Perhaps your alt guy can convert your 80A into an externally regulated version. I would then set her for 50-60A in "belt manager" using a Balmar regulator. This will allow the alt to run at 50-60A all day long and not burn up. A true heavy duty alt would work better but for the output you want a converted Hitachi 80A would be fine. These Hitachi's are not the easiest to convert to external so if your alt guy does not have the experience perhaps take a pass.
 
woodster

woodster

.
Sep 15, 2009
6,244
S2 9.2a Fairhope Al
Maine Sail said:
Woody,

I have many installations on similar HP engines up to 100A alts with no issues. The issues normally arise when the engine is also over propped.

I would strongly urge you not to stick with an internally regulated Hitachi. They "self protect" by reducing charging voltage through thermal compensation inside the "dumb regulator". Reducing the voltage reduces the current to the batteries and leads to chronic undercharging when the alt heats up.

With an external regulator such as a Balmar they can be wired for many scenarios and also current limited too. You can also wire in a switch to the engine panel that reduces alt output by 50% for when you need more power.

Perhaps your alt guy can convert your 80A into an externally regulated version. I would then set her for 50-60A in "belt manager" using a Balmar regulator. This will allow the alt to run at 50-60A all day long and not burn up. A true heavy duty alt would work better but for the output you want a converted Hitachi 80A would be fine. These Hitachi's are not the easiest to convert to external so if your alt guy does not have the experience perhaps take a pass.
Click to expand
thanks Maine that was some of my thoughts as to weather it could be reduce down ...that is good to know is there a part number for the balmar external regulator and if so would you be good enough to share it ...also glad you cleared up the hp issue on that little engine as far as the alt sucking up power ...I do like the little bugger it is simple to work on and as far as i can see pretty much bullet proof...

regards

woody
 
Maine Sail

Maine Sail

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Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
woodster said:
thanks Maine that was some of my thoughts as to weather it could be reduce down ...that is good to know is there a part number for the balmar external regulator and if so would you be good enough to share it ...also glad you cleared up the hp issue on that little engine as far as the alt sucking up power ...I do like the little bugger it is simple to work on and as far as i can see pretty much bullet proof...

regards

woody
Click to expand
Either the ARS-5 or MC-614 (what I use) will work. I prefer the MC-614 due to its dedicated sense wire and a few more features but the ARS-5 is not bad. For the $30.00 difference I prefer the MC-614...

If you tie to a dock after each use and have a shore charger then tweaking the alt has little benefit other than for a week or two week cruise. If however you are on a mooring or don't have electricity at the dock then a good regulator and alternator become a lot more critical..
 
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