Fried Alternator?

No he just its not worth repairing but as with all these things I wonder whether that actually means its not worth his time to repair. Very frustrating indeed. My regular car mechanic quoted £90 for an equivalent one although I presume again this wont have the tacho connection that I presume is requred.
 
SimonP85 said:
Ok I'll leave it as it was previously!

I took the damaged alternator to my local auto electrician earlier in the week and they called earlier to tell me its not repairable and that a new one would be ~£170 and that he'd then have to solder on the tacho connection. Does anyone have any other suggestions?
Click to expand...

Of course I don't know your exact circumstances, but from my experiences you have to do a helluva lot of damage to make an alternator non-repairable. After the diode pack - which are not usually hugely expensive, the stator brushes and stator and field windings are of quite thick copper and difficult to "blow up".

Sounds like somebody doesn't recognise the unit and would prefer not to hunt around for bits.

The first thing is to contact Beta and ask for the make and model No:- if that's not known to you. A the same time ask what the size is; i.e. fixing code (sorry, words fail me at the moment).

I found these people very helpful

their 'phone number is in the listing. Knowing the type may help them to suggest an alternative. A Lucas type fitted my Beta, but then it's a much bigger engine.

There's nothing magic about an alternator (for your application)- voltage, current output, rotation direction and speed for best output (some high output units have to be turned over really fast) and size / mounting type are the major points.

I've just seen your latest post which confirms my argument.
Additional thoughts are:-
1). "Most" alternators have a tacho output, certainly the A127 quoted does. What you may need it a field wire if yoy're using an Adverc or whatever. AutoElectrics will do one for you.
2). I'm not convinced that an insulated return type is absolutely necessary, as that wire is usually taken to the engine earth pretty near to the unit anyway. Somebody, somewhere on a formu led me to believe that it was probably to do with possibility of sparks if there was a short. I think it's more a potential hazard issue than anything to do with galvanic action. My alternators are standard vehicle type and my Beta is still in one piece. The point is that an automotive unit is a lot cheaper than a "marine" one....
 
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SimonP85 said:
No he just its not worth repairing but as with all these things I wonder whether that actually means its not worth his time to repair. Very frustrating indeed. My regular car mechanic quoted £90 for an equivalent one although I presume again this wont have the tacho connection that I presume is requred.
Click to expand...

You can easily add a tacho wire. Simply solder one on to the winding side (AC side) of one of the diodes and lead it out through the ventilation holes.
 
Once I've retrieved the damaged unit from the garage I'll have a look and get in touch with the eBay shop (thanks for the link) and see what they have that's compatible. Their prices certainly look far more reasonable.

I certainly don't think it was a marine unit before (its a Delco of some form) so not too worried about paying over the odds for a replacement marine one!

Thanks for the tip regarding the tacho wire too. The £170 unit that was recommended didnt have a tacho wire and the guy said he'd be able to put one on for free - I'd certainly hope so now knowing how simple it is!
 
Once I've retrieved the damaged unit from the garage
Click to expand...
I hope you didn't take it to an ordinary garage. All they will do is flog you a replacement.

We meant you to go to a specialist auto electrician. The sort of place that repairs alternators and starter motors etc as their core business.
 
Yes it was an auto electrician, not a standard garage. Even has "specialist in alternator and stator motor repairs" on the door!
 
Got the alternator back this morning. Its a Denso 16241-64012. Have had a call round various outfits today and got prices ranging from £100 to £198 for a replacement! Think I'll be going for the £100 option, I certainly can't find anyone offering parts or who is keen to repair it.
 
lenseman said:
Hmmmm, interesting? :confused: Stator Brushes eh?

Where do they fit on an alternator? :rolleyes:
Click to expand...

Definitely having a Senior week today (!)
Well, the brushes are static innit?
Meant to say "rotor" or "field" brushes, but was concentrating on thinking which windings one could manage to blow when applying the unit's rated voltage.

Glad to provide occasional amusement...
 
TrueBlue said:
. . . Meant to say "rotor" or "field" brushes, . .
Click to expand...

I'll let you off as it is Friday but the stator is the field and it remains stationary and therefore does not require brushes? It is the rotor which would require brushes, well it was when I did my intensive Lucas Alternator course in Birmingham in the late 70's when I was an RAC engineer.

http://en.wikipedia.org/wiki/Stator

Have a nice weekend :)
 
My turn, my turn

lenseman said:
I'll let you off as it is Friday but the stator is the field and it remains stationary and therefore does not require brushes? It is the rotor which would require brushes, well it was when I did my intensive Lucas Alternator course in Birmingham in the late 70's when I was an RAC engineer.

http://en.wikipedia.org/wiki/Stator

Have a nice weekend :)
Click to expand...

Thanks for the wikipedia link (When I'm confused I should always look there first)

But you're muddled too. In a dynamo the stator was indeed stationary, and all the power came out of the rotating bit via brushes on the commutator. This was a Bad Thing as it was difficult to get any real power out of the whizzing thingy 'cos it was small and the wires inside had to be thin.

When electronics moved into solid state devices it became possible to reverse the roles so that the field could be placed on the rotating part which had the limitation of not being able to carry much current (but quite adequate for a field winding). There's more space on the fixed stator part for heavy wires = a greater current could be generated, and the solid state diodes turns the resulting AC voltage into DC. Add an electronic controller to manage the field winding - that controls the output voltage, and the commutator is replaced by a pair of slip rings instead of a chunky bit of copper segments which wore out the brushes pretty quickly.

Every one wins 'cept for those who studied 'leccy in the days of valves and dynamos.

So I reckon it's a gentlemen's draw. My faux pas in exchange for your's, no need for Ensigns at dawn, and everything's in the garden is rosy ('cept that it's tipping with rain here).

I'm obliged to you kind Sir.
 
I know that this is not of much use to those outside the midlands area. Actually not much use to most boaters as Nottingham is about as far as you can get from the sea no matter which way you travel.

However "Midland Magneto" based in Notts have never failed to repair anything dynamo or alternator related that I have given them.

They still have their repair shop with real experts, the type that will dismantle alternators, replace diodes etc.

Worth remembering their name, especially if your are Midlands based, and have car electrics troubles.

Over here in Georgia, nothing gets thrown away, there is always a way to repair something.

My old 1969 Land Rover alternator (it had already been converted from dynamo) gave up the ghost. Diode pack rebuilt by real good electronics guys with diodes from an old Russian TV set, bearings replaced at the local trolley bus company repair shop as they had the correct bearing puller (as opposed to a guy with a hammer) bearings bought from local market from "The Bearing Man" Russians copied/adopted interntional bearing sizes, engineering is the same the world over.

Sorry most of the above sounded car related, but to me it is just engineering, nearly everything can be repaired, and at a reasonable price if you know where to go.
Unfortunatley the throw away and buy a new one trend has established itself in UK and most western econnomic areas, and also the double the price if you mention the boaty word.
 
Update...

Been down to the boat today and for my own sanity (and before shelling out for a new one) I replaced the old alternator and started the engine (having charged the battery from the mains charger - we're usually on a swinging mooring so not a regular option!)

With the engine running I put a multimeter across the output terminal and -ve and measured ~13V. I then placed the multimeter across each of the batteries and recorded a steadily increasing voltage on each battery. I presume this means that the alternator is not completely shot, however I had no way of measuring the current output which I presume could be the main problem?
 
Without a 'hands-on' look it is very difficult to draw any further conclusions about the state of your alternator. If it had smoke coming out of it, even a small amount, it tells me that it was certainly overheating and possibly have some insulation burn out or breakdown.

I don't think the ~13 volts you measured tells me very much, if that is the only instrument you have to hand then you really need to measure the battery voltage BEFORE the engine is started and then note the battery voltage with the engine ticking over and also at a fast idle, or engine cruising speed. The different voltages under that test would explain a bit more, but not fully.

I have a large 100-Amp 'Snap-On' meter with attachment leads for 'in situ' alternator testing but I will not be own on the Solent for a few more weeks yet if that is of any use to you.

Oh, and another test you might like to perform:

Start the engine and load up the batteries such that they are having to deliver as much load as you can possibly demand of them. Leave the load on and note the voltage as before but leave the engine running at a fast idle. Because the alternator has been fitted to your boat to meet all the demands placed upon it, you should still have 14 volts into the battery measured with your meter.

Further to the above, if one (or more) of the three phases inside the alternator has failed, the body of the alternator will get extremely hot and you will be unable to put your hand on its casing, you will burn yourself. The heat is being generated by the other two phases trying to supply the demand from the batteries. I don't mean warm, I mean very HOT such that a licked wet finger will steam, similar to but not quite as hot as a hot iron!

Get back to me if you need any further help? :)
 
SimonP85 said:
Ok I'll leave it as it was previously!

I took the damaged alternator to my local auto electrician earlier in the week and they called earlier to tell me its not repairable and that a new one would be ~£170 and that he'd then have to solder on the tacho connection. Does anyone have any other suggestions?
Click to expand...

Did your auto electrician say why it was not repairable? There is actually very little to 'blow up' in an alternator apart from the diodes and regulator.

My guess is that you have blown one or more diodes. If so, these are often replaceable, although the fact that your 'man' says it is not repairable makes me think (unless he's a shark) yours may not be easily replaced.

Is there no way you can measure the current from the alternator? Even a cheap multimeter can usually measure up to 10A.

When you were measuring the voltage as per your last post, did you try loading the battery/alternator i.e. turning on all your lights or other power hungry devices? If not, this might be the next simple test - measure the voltage as you add load. If the voltage remains high, above say 13.8V, then the alternator is probably OK. Wishful thinking, I reckon, but maybe worth trying. :)
 
It looks encouraging but you may well have blown some of the diodes which will mean that you wont get the full (current ) output

You could take a risk with it, keeping an eye on how well it performs.

However the only sensible option, IMHO, is to get it checked and repaired by an auto electrician who is prepared to do it as opposed to flogging you a new one. If you really cannot find someone to repair it then replacement is the only option. Maybe Denso parts are not readily available.

Provided you know what you are up to it would not be impossible to pull it apart yourself and test the diodes in the rectifier.

The heavy leads from the coils will be soldered directly on to it so a good hefty soldering iron will be required, or the nerve to do it with flame.

In most cases you will find that the rectifier consists of 6 diodes making up a 3 phase rectifier plus another 3 that supply the field current.

I have repaired my own in the past. One, at different times, had new brushes, a new rectifier, a new regulator and new slip rings. Another I looked at and ducked out of repairing myself!

Not near Tunbridge Wells by any chance?
Curd Bros have a good reputation but are not cheap.
 
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