Charging system

[EZ]

Stop at Napa yesterday to get a single wire alternator for my mill and ask the guy how much power will it take away from the motor when charging the batt. He said it takes 15 hp when charging, so that means I'll have 1 hp left for sawing. ??? Dont know if this guy knows what hes talking about or not, but I do no that I've seen WM's and Baker's mills with this type of alternator on them for charging. If this is true, what do you guys do when your mill is charging, wait until it gets charge up before sawing.
EZ

[Ianab]

Doesnt sound right to me . ???
If the alternator puts out say 30 amps at 12 volts.. thats ummm.. :P 360watts of power. It's not gonna be 100% efficient of course, so maybe it will take 500 watts of power to drive it. Thats less than 1 hp.


ian

[Minnesota_boy]

An alternator will take a fair amount of power, but it would have to be a rather big one to take 15 HP.  They only take that amount when they are charging the full capacity.  I try to never let my battery run that low that it need the full capacity of the alternator for any length of time.  Most of the time the alternator is just idling along, with minimal output to maintain the battery.

[VA-Sawyer]

A 15 hp generator set will put out about 8000 watts. At 12 volts that would be about 670 amps. So a 65 amp altenator can be expected to pull around 1.5 hp at max output. My  61 amp altenator is running close to  max when I have the debarker engaged. I can't say that I've ever noticed the loss of hp to the blade. I think he may have dropped a decimal point.
Or maybe it was the ball.  ;)
Just how big is this altenator you bought ?

VA-Sawyer

[isawlogs]

I've changed from the original Japanise 61 amp  alternator to a 100 amp delco on my LT40HD and never noticed any diference . My main reason behind the switch was cost I could get a rebuilt delco for less than 100.$ where as the japan unit was costing me 200.$ to get rebuilt.  No modifiing of the mill what so ever the same plug and bolting just took one off and put the other on . The only difference I seen was positive in that the batery charged up faster after loading and handling of each log ...no diff on the motor for sawing ...had all the power it needed and then some ....
 I don't know anything about numbers relating to amps verses HP  But those that where given to you sure seem like they are questionable. (15 HP )
 I'd sooner beleive the 1 HP would be closer to what it should be

[Fla._Deadheader]

  Ohm's law (partially). Volts X Amps = Watts
  746 Watts = 1 HP

  We are having a 100 Amp Delco Alternator re-built and pulley changed for our (LT40) similar Bandmill, 24HP Gas.  

  To use the above info:  12 Volts X 100 Amps = 1200 Watts
                           1200 Watts divided X 746 Watts = 1.60 HP
     Including inefficiency for converting Gas engine drive belt, I can safely figure 2.25 HP at MAX charge rate.
  
  As mentioned in an earlier post, You would probably never need full output.

  On the little Jap Alternator I had rigged up, we just BURNED up the regulator, FLAMES, and the Alternator was so hot you could not touch it.  When we saw, we need POWER  ;D :D :D :D :D :D

[D._Frederick]

Two things:  Fla._ , when you have the pulley changed  on your alternator, make sure the fan is drawing air through the alternator, or good by rectifiers.

On the WM mills, the hydrualic system is run off the battery. The alternator will be putting out maximum amps if it is turning fast enough. This is when your engine load will be the greatest from the alternator.

[Fla._Deadheader]

Maybe in Canuckville ;D :D :D :D  Not in the US of A

[Captain]

Must be that metric HP .  In US Standards 1HP =745.7 Watts

Captain

[SwampDonkey]

Ok your right , I was wrong for once. Gotta give you guys something to boast about sometimes.  ;) :D

[EZ]

I have'nt bought it yet cause I just wanted to check with you guys first. All he told me was it takes 15 hp and the motor has to run it at 650 rpm before it will charge.
EZ

[Fla._Deadheader]

If you don't have electric hydraulics, I can't see you needing a 100 Amp Alt. A 55 Amp should be plenty.

[EZ]

The charging system will be used for the loading winch and a couple dogs and electric drive for the carrage and up and down. I think I put to many (ands) in that sentenced. ;D
EZ

[Fla._Deadheader]

  AHA, looks like yer goin "uptown" with that mill, EH ???  ;D

  Still think 55 would be plenty with that 16HP engine.

[SwampDonkey]

Father used to have an invertor installed under the hood to run power tools and a weldor and electric fuel pumps. For welding he had a throttle under the hood where he brought the RPM's up to get enough juice to weld. That setup eliminated having to run the equipment from the field to the shop, or hiring a portable welder if a wheel broke off the harvestor or the spade needed a weld. The harvestor snapped the rear  wheel 3 times, over a 20 year period, that I can remember so there the harvestor sits until ya bring a welder to it.