Alternator wiring revisit for DUMMYs like me

[Stu Jackson]

Thanks Stu,

I did just that last night.  After realizing the NSA is now probably dialed in on me from that search I did see the noise suppressors.  I didn't thing a diesel had that much ignition noise to warrant a suppressor. (just kidding)

Steve,

NRA in addition to NSA!    Darn those noisy diesels, if you're not careful they'll shoot you right in the head if you're with the VP! 

Can't tell if the noise suppressor is connected to the alternator output.  The PO might have had noise in his stereo and thought that was the culprit.  ITWMB, I would have put a ferrite on the radio, not the alternator.  Who knows why it was installed in the first place.  You could simply bypass the wiring, fire things up and see if it makes any difference to anything you have on board.  Then you can trash it. 

[lazybone]

I'm sure it dates back to the earlier days of Loran when supposedly the equipment was sensitive to "noise".
Chalk it up to companies marketing aftermarket trash.

[Stu Jackson]

Hey, Aldo, I resemble that remark!   

I'm old enough to have had a sailboat before Loran C, bought one of the newer and fabulous West Marine, easy-to-use models, and then had the pleasure of removing the HUGE Micrologic 800 something from our boat.  I shoulda saved it as a museum piece!     Heck, maybe I have a picture of it.

We could change the title of this thread to add: "...and Old/Ancient Loran C Pictures"

What was the name of the old Magellan unit that was bigger than the old WWII walkie-talkies?

Then there was early GPS with ONLY numbers.  Yeesh, you hadda use a chart!

Those were the days, my friend.   

[stevewitt1]

Hey Stu........You're showing your youth!!!

I flew my C172 from NE Wisconsin to Panama City, FL long before the days of GPS and it was very early Loran.  When we arrived in Fl we drove to Mexico Beach and fished the Gulf with one of my passengers brother.  His 26' boat was a electronic marvel.  It was a Loran with ONLY Grid and TD numbers in the two rows of I believe Cold Cathode tubes or better known as Nixie Tubes.  Back when I built my 26' sailboat we had a wet compass and chart, that's it.


Wow, have things changed...LOL

Steve

[mainesail]

Presently, charge + output of Alt goes over to starter and shares a stud with the heavy wire going up to C post on OEM switch.
   note: OEM switches 1 & 2 both go to 1-2-B switches for a total of 4 batteries.

Some PO's do really, really, really stoopid things. Lose the extra switches. One large contiguous house bank on selector post #1 and one start/reserve battery on post #2. If you want to make charging easier wire in an Echo Charger or ACR between banks.

The gray thing looks like a capacitor and I have no idea why it would be there but if we look at the PO's switch configuration it is safe to say he was a Rube Goldberg fan....

Rx:

*Remove to extra batt switches

*Make house bank one contiguous hard wired bank

*Wire alt to house bank with a fuse at 150% of the alts output rating within 7" of the house bank + post.

*Install a service disconnect switch for the alt in the engine bay to de-energize it when servicing the engine.

*Run alt ground wire same size as positive direct to house neg bus..

[KWKloeber]

*Run alt ground wire same size as positive direct to house neg bus..

One thing I might add is that both Neg Alt B- / Pos Alt B+ really need to be upsized (probably #10 now) to 8 AWG (or 6 AWG like you like to use due to crimping.)  BTW RC, I would a very cool crimper for 8 AWG FTZ starter lugs.   


Cheers,
Ken

[dfloeter]

I am ready to install my new Balmar 120 amp alternator and wonder if anyone has found a short and easy path for the AO cable.   The best I can find is to drill another hole outboard of the engine bed in front of the existing hole used by the pair of cooling hoses and insert a grommet.   Theoretically there is ample space beneath the galley sole for more wires.

If I have this right, the 2/0 AO will run to the bank, a 2/0 ground wire to the block and a new 2/0 ground back to the bank.  The alt is ungrounded and requires the extra ground.  The 2/0 size is based on the estimated wire run and is perhaps a bit oversized.  The existing AO cable will remain but only run from the starter to the panel switch on 2 to be connected to a starting or reserve battery.   

Looking for a route.  Thanks

[Stu Jackson]

I installed #2, NOT #2/0 for a 100A alternator.  2/0 is waaaay overkill.  The routing is simple: under the engine bed, no holes to drill - two wire clothes hangers will do it for you to push or pull 'em through.

[dfloeter]

Thanks Stu.   I hope I wasn't sounding obtuse.  My alternator salesman recommended the larger wire and I wasn't even buying the wire from him.    I figured the only harm is to my wallet and I will have way less than a 3% drop.   

As to the route foreword, my 1996 engine pan has no openings toward the front but I can drill through the port bulkhead into the space below the head sink and access the bilges from there.   I will also mount my regulator in the same space although this year's (1996) access door is too tight to reach through to easily work inside.   I need a twelve year old electrician. lol

I am gradually whipping this boat into shape having removed all the loose Romex wire, taped twisted wire connections, wire nuts and other scary things.   My wash down pump works like a champ, the head is rebuilt and summer is ending soon.   We will get one 2 week cruise this year and hopefully something longer in 2015.   

[lazybone]

When I measured the length for the new wiring on my ~100a alternator (going and returning) to my 4-6v batteries mounted in the settee forward of the sink, the size charts recommended 2/0.
Anything less would have the voltage drop above 3%.

But maybe I messed up and over did it?

[KWKloeber]

When I measured the length for the new wiring on my ~100a alternator (going and returning) to my 4-6v batteries mounted in the settee forward of the sink, the size charts recommended 2/0.
Anything less would have the voltage drop above 3%.

But maybe I messed up and over did it?

What length is the run?

At 100-amp current,

  #2 AWG loses 0.032 volts or 0.27% per foot of cable.
#00 AWG loses 0.016 volts or 0.13% per foot.


-ken

[lazybone]

When I measured the length for the new wiring on my ~100a alternator (going and returning) to my 4-6v batteries mounted in the settee forward of the sink, the size charts recommended 2/0.
Anything less would have the voltage drop above 3%.

But maybe I messed up and over did it?

What length is the run?

At 100-amp current,

It was a long time ago but I remember something a bit over 20', so 2/0 wasn't outrageous.

  #2 AWG loses 0.032 volts or 0.27% per foot of cable.
#00 AWG loses 0.016 volts or 0.13% per foot.


-ken