Alternator Q?

[andythilo]

Hi

I'm trying to figure out the power wiring on my boat. Can someone tell me that the cylinder thing is that is between alternator and the power cable to the battery?

Is it some kind of regulator or capacitor?

Thanks

 

[Roberto]

it may be an interference filter, or "noise" filter (electrical noise of course :smile

 

[VicS]

Solenoid for starter motor?

How about a photo ... we dont have much to go on.

What engine is it?

 

[ksutton]

In line fuse?

 

[Roberto]

are they anything like these two capacitors, the silver one on the left and the black on the right ?

 

[halcyon]

are they anything like these two capacitors, the silver one on the left and the black on the right ?

Suppression capacitors, stops the buzz you get on a radio from the alternator.

Same as you fitted on the car ignition circuit.

Brian

 

[andythilo]

Sorry guys not much to go on. I'll take a pic later.

It looks like a solenoid but why would it be connected between the alternator and the output?

The engine is a petrol BMC Newage Navigator.

 

[Roberto]

you may try to google with the Images tab, for "alternator noise filter" and see if you find anything similar to the device you have fitted

 

[VicS]

How many connections on it. If only the two then not a solenoid.

 

[halcyon]

you may try to google with the Images tab, for "alternator noise filter" and see if you find anything similar to the device you have fitted

I've got one sitting on my bench, they go back to the 1960's.

Brian

 

[Roberto]

I've got one sitting on my bench, they go back to the 1960's.

Brian

yes I know what they are
I posted the internet picture above with the two alternators to see if the original poster recognized a setup similar to his alternator, which does not seem to be the case

 

[pappaecho]

I dont know how old the engine is, but my old Perkins 4108, born 1978, had an external diode pack and controller. Could it be one of those?

 

[noelex]

Is it a solenoid to isolate the negative supply ?

 

[seadog30]

Old Altenator

Most Perkins 4107's and 4108's were fitted with the Lucas 11AC Alternator which has an external regulator (the black plastic box with three terminals) which is Lucas part number 4TR the system is powered by the rectangular metal case device which is a simple 12V relay Lucas part 6RA, the charge warning light which is connected to the 4TR is a small metal cylinder with 3 terminals Lucas part 3AW. This system was fitted to many classic cars in the 1960's including Jag E types, Rolls, Aston Martins, Triumph Stags etc.

None of these are connected to the alternator output as you describe the device I believe you are looking looks a bit like and ignition coil and is a split charge relay. The charge from the alternator is connected to battery one the engine start battery until this battery has a good level of charge and when this battery is "healthy" it connects to battery two as well to charge both batteries.

DON'T tinker with this system just make sure all of the wires and connections are in good order and the fan belt is not slipping. All of the parts are as rare as hens teeth and more expensive.

When you do get a fault don't bother to try to repair or replace one part or another just remove the lot and buy a new modern altenator with a built in regulator and a modern split charge system.

Best of luck

 

[NorthUp]

.... the device I believe you are looking looks a bit like and ignition coil and is a split charge relay. ....

I agree.... but they have diodes inside, not a relay.

 

[andythilo]

Most Perkins 4107's and 4108's were fitted with the Lucas 11AC Alternator which has an external regulator (the black plastic box with three terminals) which is Lucas part number 4TR the system is powered by the rectangular metal case device which is a simple 12V relay Lucas part 6RA, the charge warning light which is connected to the 4TR is a small metal cylinder with 3 terminals Lucas part 3AW. This system was fitted to many classic cars in the 1960's including Jag E types, Rolls, Aston Martins, Triumph Stags etc.

None of these are connected to the alternator output as you describe the device I believe you are looking looks a bit like and ignition coil and is a split charge relay. The charge from the alternator is connected to battery one the engine start battery until this battery has a good level of charge and when this battery is "healthy" it connects to battery two as well to charge both batteries.

DON'T tinker with this system just make sure all of the wires and connections are in good order and the fan belt is not slipping. All of the parts are as rare as hens teeth and more expensive.

When you do get a fault don't bother to try to repair or replace one part or another just remove the lot and buy a new modern altenator with a built in regulator and a modern split charge system.

Best of luck

Thats just the thing, I have bought a modern VSR cluster which I want to install. My alternator only spits out 10-15A max as measured by an inline ammeter, and thats at full throttle!. Mind you it's only a small battery bank, which is also strange.

Whoever fitted it out before me, put a 110ah leisure battery on the starter motor and a 70ah leisure battery for the house. I've ordered 2 new 85ah batteries for the house and i'll leave the 110ah alone as it cranks very well.

 

[seadog30]

Volts drop

I note that you have an "in-line" ammeter.

With this set up all of the charge from the altenator is going via the wires to and from the ammeter. I have often seen these replaced by someone who assumed that as they only went to a meter they could be thin low grade wire. Wrong any resitance in this circuit will cause a volt drop which will significantly affect the charge available to the battery.

Make sure that all connections are 100% and the wire is 6mm or more if longer than a couple of feet.

 

[andythilo]

Well what a job that was!. I've replaced all the wiring from batteries to alternator and to starter. All main wiring is now 25mm2, alternator to VSR cluster is 10mm2 as it appears that the alternator is 15-20A max.


The item in the original Q has the following connections :

I/P from Alternator(O/P)
GND
O/P to Batteries
Sense Wire from O/P to Alternator O/P

Boat starts even better now, fires instantly. All GND wiring replaced, some really old **** braid strap in there, most of the wiring had oxidised badly.

Got a bit of tidying up to do with 'p' clips.

Also managed to get my Amp and speakers hooked up so we had tunes

 

[Chris_Robb]

Well what a job that was!. I've replaced all the wiring from batteries to alternator and to starter. All main wiring is now 25mm2, alternator to VSR cluster is 10mm2 as it appears that the alternator is 15-20A max.


The item in the original Q has the following connections :

I/P from Alternator(O/P)
GND
O/P to Batteries
Sense Wire from O/P to Alternator O/P

Boat starts even better now, fires instantly. All GND wiring replaced, some really old **** braid strap in there, most of the wiring had oxidised badly.

Got a bit of tidying up to do with 'p' clips.

Also managed to get my Amp and speakers hooked up so we had tunes

So far , no one has mentioned voltages during charging. I am assuming you have ordinary refillable wet lead acid batteries. To check the voltages accurateley you will need a digital multimeter. The static voltage of a well charged battery (resting for several hours) is 12.7V. When you start the engine, the voltage should rise at once, and continue rising until it reaches 14.4V or if you charge hard 14.8. It is therefore worth checking what voltage the alternator is producing AT the battery. Older alternators only really trickle charged, and 13.2 to 13.5 was a common voltage to get.

You say that the best ampage you have seen is 20amps. If you have a 50 amp alternator you should see double that intially, reducing as the voltage rises, to say 15 amps when the volts have got to 14.4.

If you have one of these older alternators, then add an inteligent charge controller from the likes of Sterling. This will then get the alternator producing what it should - and charging the batteries to their correct level.