alternator connection

[davec]

I have recently replaced my alternator and the new one is "self-exciting". The new one requires 24v at the +ve terminal on the alternator to self-excite; how can I connect it to charge 2 battery banks? Less importantly, how can I connect my ignition light?

 

[pampas]

What type ?

 

[rhumlady]

You do have a 24Volt supply in your boat don't you?

 

[VicS]

I don't understand you. Firstly you say your new alternator is self exiting but then you say it requires a 24 volt supply to excite it. That appears contradictory!

Old fashioned dynamos were self exciting relying on residual magetism to start generating but alternators generally aren't. They rely on a small currrent feed from the battery via the warning light to provide the initial field magnetism.

If it is truly self exciting maybe there is no provision for a warning light. You will then have to rely on instrumentation ie ammeter and/or voltmeter.

Maybe the section on alternators on this site will be of use to you

 

[William_H]

My guess is that you might be confused with "built in regulator" a box attached to the end opposite the pulley which has attached to it the brushes (if you remove it) and wiring probably attached.
There will be a large terminal possibly on the end plate of the alternator which connects to the battery positive (via an ampmeter preferably)
There wilkl be a smaller terminal possibly on the regulator which is connected to the battery 24 volt via a small lamp and the key switch or ignition switch or alternator switch. This is where the excitation comes from and the lamp will glow when excitation is being provided. When the alternator starts to generate power it will provide it's own excitation so no current flows through the lamp (no glow).
The power via the lamp needs to be switched off after finishing with the engine otherwise there will be a discharge of 1/4 amp or so.
This is the general arrangement i hope it helps Merry Christmas olewill

 

[pampas]

Impossible to give any advise until the type is known, CAV,Bosch Lucas.

 

[davec]

The alternator is a Canadian made RCP. There are two other connections on the back of the alternator, identified F & R.

 

[VicS]

I think you need to establish exactly what those connections are.

Maybe the website at rcpcanada.com would be a good stating point or perhaps it would be worth contacting them directly for info on your machine. Do quote the exact model number though.

Have you considered that it may need an external regulator? Or do you actually have it running and charging satisfactorily.

Regarding charging two battery banks you have two choices. Either use a VSR or if the alternator is, or can be converted to, battery sensing use a split charging diode system. Alternatively of course you could simply use manual switching provided you are careful to never disconnect both batteries while the alternator is running.

 

[pampas]

Try this link www.rcpcanada.com should give you all the info that you require.