Alternator woes

D

doctormilner

Active Member
Joined
13 Mar 2009
Messages
44
Visit site
Hoping someone with some electrical expertise can help explain what’s happened ; my yanmar engine (yr2000) has 80 amp hitachi alt. which recently stopped working. A marine electrician took it to workshop and declared not worth repairing. I purchased an aftermarket (not hitachi) supposedly direct replacement.He fitted it and it burned out the rectifier, my sterling alternator controller and my rev counter doesn’t work. He said something vaguely about not noticing a wire on the side of the alt. which I think may have shorted.He refitted the original alternator which he got working, He hasn’t found a new rectifier yet. Could the new alternator i purchased have caused this or his incompetence?
 
Sandy, he installed it when I wasn’t on the boat and it would have been impossible for me to see wiring as access is in aft cabin through small hatch. Purchased on eBay ,obviously Chinese with many similar ones from many sellers available , supplier CPSeuropean with alleged 12 Month warranty which would be difficult with what i am presuming is a fried rectifier.
 
The Sterling alternator controller may have required the original alternator modified to allow it to work. This requires a connection on to one of the field brushes and depends if the alternator is Positive or Negative type field control. Without this field bypass the Sterling likely won't work. If it is a Positive type and it found its way to ground (negative) this could definitely cause issues.

The wire mentioned on the old alternator may have been this bypass wire. As to whether a professional would know this is debatable - is a professional expected to know idiosyncrasies of bolt on extras like a Sterling controller ? I know because I fitted on on my boat before last. Instructions attached explain how it is connected.
 

Attachments

OP, have you got the exact details of the original alternator, the Sterling regulator, and the new alternator?

This is a 12V system, right?
 
superheat6k said:
The Sterling alternator controller may have required the original alternator modified to allow it to work. This requires a connection on to one of the field brushes and depends if the alternator is Positive or Negative type field control. Without this field bypass the Sterling likely won't work. If it is a Positive type and it found its way to ground (negative) this could definitely cause issues.

The wire mentioned on the old alternator may have been this bypass wire. As to whether a professional would know this is debatable - is a professional expected to know idiosyncrasies of bolt on extras like a Sterling controller ? I know because I fitted on on my boat before last. Instructions attached explain how it is connected.
Click to expand...

Thanks for that, I will enquire. Bob
 
7528E628-8315-41F1-A424-5273C469CCA9.pngAF336828-E45C-4CC0-84F0-DEC5AC5952E7.png
dom said:
OP, have you got the exact details of the original alternator, the Sterling regulator, and the new alternator?

This is a 12V system, right?
Click to expand...


7528E628-8315-41F1-A424-5273C469CCA9.pngAF336828-E45C-4CC0-84F0-DEC5AC5952E7.png
dom said:
OP, have you got the exact details of the original alternator, the Sterling regulator, and the new alternator?

This is a 12V system, right?
Click to expand...
Hitachi lr 180-03C 12v
will have to get Sterling info on boat tomorrow remember it cost about £240

bob
 
Cheers, the reason I’m asking is that if this was a straight swap then something has obviously gone badly wrong.

But if the original system had user mods it would useful to get a clear idea what these were.
 
doctormilner said:
Sandy, he installed it when I wasn’t on the boat and it would have been impossible for me to see wiring as access is in aft cabin through small hatch. Purchased on eBay ,obviously Chinese with many similar ones from many sellers available , supplier CPSeuropean with alleged 12 Month warranty which would be difficult with what i am presuming is a fried rectifier.
Click to expand...
I use Alternators & Starter Motors for Car, Marine, Plant, Agricultural, Commercial in Plymouth, always spot on with their advice.

Always worth being about when anybody tampers with your boat, use them to learn how it works, or not in this case, as they will not be about some cold wet night when things go FUBAR.
 
I think Superheat6k has it in post no.5 above.

Sterling alternator controller typically requires modification of the the alternator's internal wiring, so the Sterling directly controls it. OP said '[Engineer] said something vaguely about not noticing a wire on the side of the alt. which I think may have shorted.' So it seems he's ignored or missed the special wiring, connected it as standard and the damage is the result of that.

I doubt there is (was?) anything wrong at all with the alternator itself.

See the Sterling instructions Superheat attached, specifically that part labelled 'Installation'. That is what needs doing to the new alternator so it is controlled by the Sterling (if those two items have survived or are salvageable).
 
Thanks everyone for your replies superheat6k and little sister have confirmed my thoughts and sandy thanks i frequently take the boat to Plymouth for any major work from jersey and yes i would have installed the alternator myself except I hadn’t a clue about the Sterling connections
bob
 
doctormilner said:
i would have installed the alternator myself except I hadn’t a clue about the Sterling connections
Click to expand...
It looks like your 'Marine' Electrician hasn't either! I would sack him, but if you are in Jersey, your choice is probably a bit limited.
He should have noticed that you have a Sterling unit fitted, but equally you should have pointed it out and given him the 'book'.
 
Lady in bed , he has worked on boat for last 9 years! And was fully aware of sterling and the 3kw pure sine inverter /charger and where i keep all the manuals. He is over retirement age , and like me starting to lose it a bit. I can feel a trip to Plymouth beckoning if this weather ever relents.
 
This manual has a better explanation of how direct field control works, and the difference between Positive and Negative Field control.

The Sterling is simply an electronic version of this quite old idea.

Page 147 onwards (not my scan - I found it on the net somewhere) ...

12volt handbook.pdf
 
superheat6k said:
This manual has a better explanation of how direct field control works, and the difference between Positive and Negative Field control.

The Sterling is simply an electronic version of this quite old idea.

Page 147 onwards (not my scan - I found it on the net somewhere) ...

12volt handbook.pdf
Click to expand...
It might have come from my site Downloads : Monty Mariner but it on available in several sites.
 
You must log in or register to reply here.

Share this page

Top