When adding lights to a tractor......

[dcyrilc]

Yeah I know what you are saying, I am very particular when I do things. I could not spend that much money on a tractor and do shotty work to it. I will definitely check out the factory stuff 1st and go from there. I just want it to be bright out on them cold winter nights!

Are you familiar with JDParts? It's basically all the JD parts manuals online. If you register with the site, you can even see what the price will be at your local dealer and if they have the part in stock. Also if you don't have the technical manual for your tractor, IMHO, it's worth spending the money. I prefer the paper manual, but many get the manual on CD and just print the pages they need for use in the shop as they need them.

 

[Soundguy]

I finally found some discussion on the 10 and 12si gm alternators .. the ones I'm most familiar with.. as they are a favorite of the antique tractor crowd ( so are the cs 130 )

this came from madelectrical.com:

"Burned stator windings are common, in applications that continuously require a high amount of alternator output, and so are heat-damaged rectifiers. Some alternators are able to constantly put out a fairly high percentage of their gross output rating. Yet other designs fail when producing only about 50% of their gross output rating. For that reason, the author’s preference is always a good margin with cooling capacity per electrical power output. The models 10SI and 12SI alternators have proven to be very rugged with “stock” winding installed (output not greater than factory ratings). And for their cooling capacity, “stock’ model 10SI and 12SI GM Delco built alternators are favorites.

"

I'ts clear from any amount of internet searching that I'm not the only person that views alternator outputs with a degree of margin as being a good idea. as i stated before.. much of it is a thermal mass issue, vs cooling.


more research turned up this formula for calculating heat, as disipated in watts:

The math formula for calculating the amount of heat is AMPS2 X OHMS = WATTS (of heat). It’s interesting with this formula that AMPS is squared.

In the case of current flow through the stator winding, the outcome will be that when the AMP output of an alternator is increased by only a few percent, the heat output will double in amount. In example, with a 40amp output; 402 (AMPS) X 0.05 (OHM) = 80 WATTS of heat. But when output is increased to 60amps; 602 (AMPS) X 0.05 (OHM) = 180 WATTS of heat! (The 0.05 ohm resistance at the stator, which we used, is only an example quantity, but it, may be close to a real world number.) And so with output increased from 40 amps to 60 amps, the amount of heat output at the same stator winding is more than double!

"




soundguy

 

[Down South]

I saw this thread and thought i would chime in.

Soundguy is spot on.

Yet there are other factors that have been over looked.

Most alternators are rated at 5000 rpm.
Most will produce 60% of rating at idle speeds, on a car with a good Overdrive speed. Look at the pulley sizes.

Most tractors Max out at 2500 rpm or less.
Most have large pulleys on the alt or gen.
Most are normally run at 1800 rpm or less?

So how fast are they actually turning? Not near as fast as on a car or truck.
So you get less output and more heat faster.

Don't expect max amps even WFO!

I like the 12si, common proven design. slightly more cooling and higher outputs. 66.78 and 94 amps. Trim the spacer moving the fan closer for marginal more air. Aftermarket rectifier with the twisted fins and 50 amp diodes ( 50x6 3 pos 3 neg = 150A) it can withstand extremes better.

DS

 

[OkieDave]

"references? I could send you a copy of my engineering degree "How many alternators have you seen "burned up" by running at capacity? In fact, how many alternators have you seen burned up at all? (Heresay has that most alternator failures are bearing failures.)

One. 1993 Socata TB-9 Tampico, and the maintenance logs showed that it had a history of puking alternators. I can't speak as to the ones before I flew it, but that one definitely burned out.

Yes, it's an airplane, not a tractor, but looking into that issue revealed some information that might be pertinent here. We found that the entire line of TB-9's had a reputation for killing alternators. Looking at the installation, I can kind of see why--the ventilation for the unit came through a small (1", if memory serves) pipe, then to a shroud. Without actually measuring anything, I'm not at all uncomfortable saying that the installation design did not provide enough cooling airflow for the unit.

As for relevance to this case, here it is: most airplanes don't have a lot of spare alternator capacity (spare capacity means extra weight), so they get run hard. The harder you run it, the more cooling (airflow) it's going to need. I don't know how your alternator is installed, where it gets its cooling air (a lot of car installations just take it from the engine compartment, which can get quite hot), etc., but if you're going to run it hard, you probably need to think about getting enough air through it to keep it from cooking.

 

[Soundguy]

i had a 84 pontiac sunbird that was good for about 1 rebuilt alt a year. I bought the local store brand with a warranty ( discount auto parts or some such.. ).. got so bad that I tackwelded tooling handles to the lockdown bolt and pivot nut so i could quick change them in the parking lot.

had an 87 t-bird that smoked an alt quite spectacularly 2 times.

once coming back from the beach.. pulled up to a stop lamp and smoke roleld out under hood, lamps and what not blinking all over.. whipped into a western auto parking lot as light changed and tossed open hood. alt had fire spikes shooting out of it and had singed but not burnt ther the underhood insulation. car staleld out.. flames kept going.. i was digging in my trunk to get a tool box.. store employee ran out with a fire extinguisher. hosed it. flames came right back. flatbed tow truck had just pulled in and tossed me a wrench to pull bat cable.. which stopped the alt smoking.

fortunately I was able to buy a alt right there and then get a tow home to install it.

other time it fialed was at night heading to a buddies house.. died at a stoplight again.. no smoke for flame.. just decided it had no more electrons left...

had a mark VIII that did that once.. 94 I think it was. darn hard to get at alternator too..

ps.. no special lighting or electrical loads on those vehicles. all stock stuff...

soundguy

 

[Down South]

Wow Soundguy you have had bad luck there.

I lost a 72 Impalla, dash light would be on some times when i went to get it on the weekends, Then i was going to it and it was cranking before i got to it the insides filled with grey smoke. total melt down of the wireing.

Turned out the tilt steering colum had pinched wires. Ended up parting it out.
On the other hand i just changed the OEM alt on a early 72 chevy truck. Orginal fake 10si w external regulator, diode leaking and kept the regulator energised. Ran the battery down in a week or so.

Electricity is a funny thing.

 

[MF 1532]

watch the wattage ont he oem wire.. if adding 2 lamps.. it's probably ok.. if adding 4 lamps I'd run the existing harness wire to a relay as a trigger, then source new wiring from the battery or a fusebox hot tap for the other lamps.


to answer the prev question.. 4 55w lamps is 220.. if the tractor has 2 35w-45w lamps plus a 5w blinker you are you are liely fine.., running the calc at 14.4 nominal charge volts with 22a available to use.. as long as the battery is up.. the 10a charge and dash cluster we set aside will likely go up, meaning you could have 2 55w tractor lamps, plus a 5w flasher.. plus the 4 added 55w lamps... just don't kick em all on right after startup befor ethe battery has replenished.. give the system a few minutes to top the bat back off after starting... then you can get all incandescent on it..

soundguy

I was wondering if it is possible to start the tractor and /or tractor off, turn everything on , and connect meter to it , to find out what total draw is on tractor ? Sounds good if it would work , might keep someone from a lot of damage . I'm just asking because I don't know .

 

[Soundguy]

seems like oem gives you the best service.. and then anything else is a dice roll.. even if it is marked new and from the dealer.. I have a feeling they are remaneed at some point.. etc..

the funny one is napa.. I was buying a starter for my 98 dodge ram 1500 ( what a PITA to change! ).. and they slapped it on the table in it's box, said.. you are lucky, we had 1 left on the shelf... then the salesman staring at the computer to ring it up started reading prices off....he said: do you want the rebuilt, with 3m warranty, the rebuilt with 3yr warranty, or rebuilt with lifetime warranty or the new one with lifetime warranty?

I looked puzzled and asked if this same starter was the same starter that would be sold as any of those prices, and was told 'yep'....

I got the 3 month one as it was 45$ cheaper than the next one up, which was 20$ cheaper from the next one up, which was 90$ cheaper than the 'new' one.. mind you.. the same starter int he same box was being sold as a rebuilt or new...

( ps.. starter is now 2ys old at least, going strong.. shows no sign of giving up.. have now sold that truck to my day job.. so i still get to see it every day.. just don't have to care for it and feed it anymore.. )

soundguy

 

[Soundguy]

I was wondering if it is possible to start the tractor and /or tractor off, turn everything on , and connect meter to it , to find out what total draw is on tractor ? Sounds good if it would work , might keep someone from a lot of damage . I'm just asking because I don't know .

yep.. ammeter will show you total load.. etc... thoug you can just as easy calculate it with known wattages..e tc..

 

[MF 1532]

yep.. ammeter will show you total load.. etc... thoug you can just as easy calculate it with known wattages..e tc..

Thanks :thumbsup: