The Stovebolt Site Forums The Shop Area The Electrical Bay Alternator Question

Hi I'm replacing my generator with an altrenator. I have a delco 10 SI. What I'm wondering about is the specs are 67 Amps which I think for my application is ok but the sheet that came with it says the turn on / excite is @ 1276 RPM's. Is that Okay or should I be looking for something different .
Thanx, Jack

osidejack,

Is this a single wire alternator?

[edit]. This IS a single wire unit. I think the RPM you indicated is the speed the alternator has to reach to initially "turn on" or self excite the windings, which means it will begin charging. Once turned on, the unit will remain so until the truck is shut off..(I think).

This is a fine choice, many folks have this style and love them. They are easy to wire and help keep the engine compartment spaghetti free.

The choice of the single wire over the more conventional three wire, brings out many different opinions...all equally valid.

Stuart

osidejack,

Sheesh, you have two posts going on this subject, so twice the blabber for me!

I assume you are aware there is more to be done when changing from generator to alternator than just bolting it on. Especially if your previous system was 6 volts.

Stuart

atomarc,
This is a 3 wire unit and yes always something to be done. I have been readin' up on several of the posts and tech tips re this change over also already 12 volt system. So I am ready to make the change. I have a 54 235.
Thanx.
Jack

osidejack,

Good show, there are many answers in the tech tip section, and in the forums when you use the "search" feature in the upper right of the page.

I am a little confused about the "excite @1276" thing. A three wire alternator is excited with a external wire (one of the three) from the key.

I thought a three wire unit would charge from the git go. Could someone have given you the wrong dope.

If the alternator has the proper voltage regulator installed (SI) it can have the two connections for the DA plug, but can function as a single wire device.

Many rebuilders use only one part number, which will allow three wire, or single wire operation.

Good luck with your swap, and keep us posted.

Stuart

Jack,

It looks like I didn't understand all I thought I knew about alternators!

The poop sheet does say that these things don't put out maximum charge until they reach a higher RPM, that must be the turn on/excite figure you posted.

Stuart

The "start" rpm is where the alternator starts to put out power. Once you start it, it will then work as any other unit would. It does not need to stay above that rpm, it will charge at idle. All that is required is a blip of the throttle or a fast idle during start up. We use these on a whole fleet of school buses with out problem. Ours are 200 amp and once they start working, it will run every light on a bus with out missing a beat! We check each one during oil changes and checks, I have seen 200 amp units put out 175 amps at idle, and thats 550 rpm on a diesel.

Tun the power wire off the alt. to the amp gauge, then out to the battery. Make it as direct as possible for the best charging. Joe

Thanx Joe Almost ready to hook up Just need'n some 12 gauge to finish with. Hopefully friday will be a go. Only one other question Which wires or should I say do any of the original wires comming from the regulator need to stay can I get rid of all or just part? Thanx again
Jack P.S. one more post and yoiu are battin' a 1000! Good Work!!

Just tape them all off, you should need any of them. The alternator is self exciting, it starts on it own and has its own built in regulator. Joe

if its the alternater i have hook the wire from the generater light to the alternater.

Joe what is the make and model on your alternator in the school buses.Ia'm looking for a 200 amp alternator for setting up refrigeration in my Forward Control Dubl duti
Thanks
Maxx