add on alternator wiring ?

[Larry B]

I have added a 12 volt alternator to recharge my house battery while driving. I removed this alternator from a vehicle headed for the scrape yard about three years ago and my senior memory is kicking in and I cannot remember the wiring between voltage regulator and alternator. From info. off the net I think the regulator needs a voltage sensing line from the battery being charged. I drew a diagram of how I believe the wiring should be. If someone who knows more than me about wiring could have a quick look and tell me how much smoke there will be when I turn this system on I would be grateful.  Thanks
   Larry B

[Larry B]

Two more pictures

[chev49]

this may be a stupid question, but why include the 24 volt system in it at all? i think if its only for the 12v house bank system, all you need is wiring your gen system up to that. 
Personally, i have used 12v gm one wire alternators for years... only one wire to hook up to the 12v system.... well, maybe a circuit breaker in there as well...

[bevans6]

I don't favor having either a fuse or a switch in the connections between the alternator and the batteries that it charges.  If the switch opens and the alternator loses the battery for regulation, it can free run and hurt itself.

Brian

[rv_safetyman]

Brian, we agree on almost everything, but not this one.

For a 30 foot 150 amp circuit, you need small welding cable.  If that cable shorts out, you could get 300-400 amps from the battery and that is the same as a large welder.

On mine, I used 200 amp fuses on BOTH ends of the circuit.

I used a Leece Neville one wire alternator.  It is a truck type (think 150 amps)  and maybe $125.  I would gladly replace the alternator rather than have a fire and or structural damage.

Jim

[bevans6]

I guess I don't know a single vehicle - car, truck, bus - that has a fuse in the charging system.  I do know of a lot of electronics that can be seriously harmed by an alternator that starts to run at 120 volts instead of 12...  Horses for courses, there are ways to do it both ways safely...

Brian

[robertglines1]

Traced to 24 volt cable short:

[biff]

Larry your wiring looks right. I dubbled checked in a dodge service manual.thy use fusible links.but i like fuses better.also you don"t need that 200 amp contactor.but it wont hurt.so you shouldn't lose any smoke! LOL. don"t forget to ground the case of the alternator and regulator there should be a stud for that.

[Larry B]

 I reason for being cautious with the disconnects was after watching the video of Robert's fire from an electric short. In a single one voltage system does the sensing line stay "alive" when the engine is shut down and key is in off position? I did not know the answer to this and the relays are left over pieces from conversion. Another thing ,I have a large house battery could make a lot of sparks, if the power  comes backwards. It is a backup battery for power failure. It is made of six 2volt cells and each cell has 750 amp/hrs capacity. If the sensing line go to the field contact on the alt. I am going to put the belt back on and see what happens.   Thanks for all help   
LarryB

[robertglines1]

I know it has effected others safety concerns. Just think what it has done with mine.! can't be tooooo careful for just a few more dollars to be extra safe..   Bob.  puttin old smokey back together.

[chev49]

i also put in welding cable and fuses on both ends... dont remember fuse sizes, one is 100, cant remember the other.