Help ! Alternator Wiring

[(unknown)]

Hi

I am building my own generator using a Lawnboy Tractor 10HP.

I managed to get a hold of a old Cadillac 1987 Alternator (Generator) with built in voltage regulator. I have been researching the literature on this alternator (I think it is a Delco CS-144). It has  one main power wire going to the battery,  a (12 gauge red wire), a 14 gauge gray wire and a 14 gauge brown wire.

Upon reading the research it appears that I can hook up the 12 Gauge wire directly to the alternator output, but there are several references that denote I must use a resistor in series to connect one (Or Both) of the other wires.

In addition I apparently need a switch to be able to deactivate the field.

IF someone could specifically tell me wich of these wire requires a switch and or resistors before connecting to the battery terminal it would be greatly appreciated.

Note: I also believe that these alternators will work in the reverse (Counterclockwise) direction. Please confirm...

[RP]

On the reverse direction part:  This is okay electrically but the cooling fan on the front of the alternator will not be as effective so overheating may be a problem under sustained high loads.

[(unknown)]

I agree.

Heating could be a concern under high loading conditions.

Fortunately, we only expect to be using this unit for Power failures in the Canadian Winter where temperatures are in the -20 - 0c range for the most part.

The Alternator is rated for 120 Amps and I don't expect to have continious peak loading exceeding 85 amps (I.E. Rating for inverter) for sustained loads. In addition it is supported by a battery bank that will provide for instantanious surges above that level.

[MelTx]

  Hello Kflack   I ran a homemade auto alt backwards it became very hot, in about 5 minutes burnt up...I dont think the cool weather would be enough.

    The small wires are to control the electric going to the Field.You have to give them some volts to make the alt start chargin...Some people think 3-4 vdc will do it.and they use a pot in line from the-- pos batt terminal--to the field..

    My setup is a external regulated alt 70s model...All I have is an on-off switch inline from pos batt--to the field termnial, this makes the alt squeeze every bit of energy out of the gasoline..About 17 vdc at 40 amps....Hope this helps.

                                                  MelTx

[(unknown)]

I am under the impression that the Delco CS 144 alternator I have has 2 sets of fans. 1 internal and 1 external, so it may help with the cooling....

Its going to be mounted facing downward as this is the only configuration where I can mount it on the tractor and have appropriate alignment with the existing pully (used for the lawn tractor blade mechanism). My only other alternative is to actually jack the entire tractor off the ground to mount it to turn clockwise.

I hope the 5 minutes you mentioned is a unique scenario with your alternator..

Just in case, are there thermal couples that kick in if the casing gets too hot ?

[MelTx]

  There is no known safety valve...Mounting with shaft verticle is no problem.

       Mount the alt on the top side of the mounting plate pointed up and it goes say counter clock........Or mount the alt on the bottom side of the plate and it turns the other way. Either way the alt shaft is vert.

[crashk6]

This isn't quite what your doing as the final output here is used for welding, BUT it will give some guidance on the control wires and what to do with them.

http://www.motherearthnews.com/library/1980_November_December/Build_a_20_Portable_DC_Arc_Welder

Copy and paste that if the whole thing doen't hyperlink.

--

crashK6

[bob g]

why not mount the alternator horizonally and do a 1/4 turn belt install.

that way you can use the vertical motor, and get the rotation you need.

quarter turns belts are not uncommon and work well if the center distances are not too close.

also bear in mind the power rating of the belt increases with increased belt length, due to less flexure

bub g

[bj]

 Hi newbie here, but have played with alts lots.  Biggest problem I had with reverse rotation was with time the nut that holds on drive would loosen.  Robbed a fan off of something else--can't remember what that had straight blades, and seemed to be ok in reverse.  Hope this is of some help bj