Electrical Limitations

   / Electrical Limitations #1  

TWD

Gold Member
Joined
Jul 18, 2010
Messages
338
Location
Sierra Nevada Mountains - CA
Tractor
Kubota M59
What is the best way to determine the electrical requirement of the tractor "as is", and then figure out how much more you can add to it w/out utilizing alternator 100% or more, and draining the battery, and potentially ruining the alternator.

Looking to add some work lights, and maybe a CB, and I'd like to know how much I have to work with.

What about adding a second battery for when say using a spot light at night for short periods?

All accessories would run off a distribution block that connects directly to the battery.
:thumbsup:
 
   / Electrical Limitations #2  
What is the best way to determine the electrical requirement of the tractor "as is", and then figure out how much more you can add to it w/out utilizing alternator 100% or more, and draining the battery, and potentially ruining the alternator.

Looking to add some work lights, and maybe a CB, and I'd like to know how much I have to work with.

What about adding a second battery for when say using a spot light at night for short periods?

All accessories would run off a distribution block that connects directly to the battery.
:thumbsup:

Simple math. Look up the specs or call the dealer to see how many amps the alternator is rated for.

Then take an amp clamp and measure how many amps the tractor uses while under normal operation conditions and the lights/flashers, etc on.

The difference between the two is about how much you have to play with.

Say under normal conditions with the lights on etc. you are drawing 40 amps and the alternator is rated for 80 amps, then you could add up to 40 amps worth of extras.
 
   / Electrical Limitations #3  
-LD- I haven't seen a "DC" amp clamp. Thought those were for AC only? But what you're saying is correct. A few work lights and a CB don't draw that much current and I haven't seen or heard of any tractor manufacturer running there alternator/generator at such a point that it couldn't handle 10 or 20 extra amps.

Good luck.
 
   / Electrical Limitations #4  
FYI the little grey market Yanmars can't even handle the head lights for a very long time. They just were not made to work at night. The make of tractor will effect this answer.
 
   / Electrical Limitations #5  
-LD- I haven't seen a "DC" amp clamp. Thought those were for AC only? But what you're saying is correct. A few work lights and a CB don't draw that much current and I haven't seen or heard of any tractor manufacturer running there alternator/generator at such a point that it couldn't handle 10 or 20 extra amps.

Good luck.

I have a Fluke 336 that does DC amps. I also hae a PDI automotive multimeter that also does DC amps. They do make them.
 
   / Electrical Limitations
  • Thread Starter
#6  
Thanks, I`ll check my clamp meter to see if it does DC and check while running, and with lights to figure out how much more I can add :thumbsup:

To go above the alt. output for short periods the battery should be ok... right? IE: Using a small electric winch.

I could add a 2nd battery someplace too for extra storage if I needed.
 
   / Electrical Limitations #7  
Dear Sir
Most lamps are rated in watts, and alts are in amps some in watts, so if you add up the watts of your lights that will be the total load in watts. So a 30 amp alt at 12 volts = 360 watts. If you want to start to running high power lights I think some off road are 150 watts per light. You could think of load sharing meaning do you need the CB on and the high power lights at the same time. Or the work lights on but drop the cab lights. Or put in a 100 amp alt , you might have to do some rewiring.
Craig Clayton
 
   / Electrical Limitations #8  
-LD- I looked up the Fluke meter but still am having problems wrapping my hands around a "DC clamp" meter. I'm not talking about the verbage on the box but the operation. AC clamp meters measure the amount of magnetic energy in a conductor and calculates the amperage based on that energy much like a transformer. However DC does not have that continuously changing magnetic field to measure. So if you could please enlighten me.

Thanks.
 
   / Electrical Limitations #9  
-LD- I looked up the Fluke meter but still am having problems wrapping my hands around a "DC clamp" meter. I'm not talking about the verbage on the box but the operation. AC clamp meters measure the amount of magnetic energy in a conductor and calculates the amperage based on that energy much like a transformer. However DC does not have that continuously changing magnetic field to measure. So if you could please enlighten me.

Thanks.

I dont know how they work, all I can tell you is that they CAN measure DC amps. Take my word for it. Maybe someone else can chime in here.
 
   / Electrical Limitations #10  
I assume it's a diesel and has no ignition load. The only thing drawing will be lights, accessories and of course the starter glow plugs and instruments. Starter and lights are only used intermittently so the total amp hour draw is very low. If your charging system is anything over 50 amps you're golden. Work lights, especially the LED type you probably won't notice. If you keep the engine on with the lights likely no worries. You may not need a second battery if a larger one will fit. A group 27 or 31 should allow lots of accessories.
 
   / Electrical Limitations #11  
Dear Sir
Most lamps are rated in watts, and alts are in amps some in watts, so if you add up the watts of your lights that will be the total load in watts. So a 30 amp alt at 12 volts = 360 watts. If you want to start to running high power lights I think some off road are 150 watts per light. You could think of load sharing meaning do you need the CB on and the high power lights at the same time. Or the work lights on but drop the cab lights. Or put in a 100 amp alt , you might have to do some rewiring.
Craig Clayton
The actual voltage when the engine is running is about 14 V. It gives you about 17% more watts. Most alrenators have overcurrent protection. In other words if you draw more current than maximum current the voltage drops to aboiut 12V and the deficit will be covered by battery. You can overload the system to the point of draining the battery. In example winch will take a lot of amps taking current from both the alternator and the battery. When the winch stops the voltage increases and the battery is recharged.
 
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   / Electrical Limitations #14  
The DC current meter uses the HALL effect to measure current. It works by a non contact induced field. Or you can run current through a meter the old fashion way.
Craig Clayton
 
   / Electrical Limitations #15  
Sir
I was trying to explain a simple approach to current calcuations without getting to deep. I was also trying to show how you do not need all the fancy meters, simple math will do. As the gentlemens inquiry was not specific as to the exact load I suggested a general overview. Short term current can exceed the rating of the alternator but if the draw exceeds time and current it will burn out or over current trip out will happen.
Every lamp has the wattage printed on the back, so if you add them all up that will be the total watts. As lamp load will be steady for maybe hours ( current consumed must = current generated ) or as you stated you will slowly drain the battery and over load the alternator.
Craig Clayton
 
   / Electrical Limitations #16  
-LD- I looked up the Fluke meter but still am having problems wrapping my hands around a "DC clamp" meter. I'm not talking about the verbage on the box but the operation. AC clamp meters measure the amount of magnetic energy in a conductor and calculates the amperage based on that energy much like a transformer. However DC does not have that continuously changing magnetic field to measure. So if you could please enlighten me.

Thanks.



Any type of current creates a magnetic field, be it AC or DC. Otherwise there would be no such thing as a DC motor, or DC generators.
 
   / Electrical Limitations #17  
-frischtr- You are correct that a magnetic field is generated with both AC and DC however inorder for a non-contact AMP meter that uses a simple current transformer you can only do this with AC. I'll have to look into hall effect for a non-contact DC meter. And as far as DC motors go there is a long explaination for how a rotating magnetic field works. But back on the meter issue as you are aware there isn't a DC transformer same prinicple as the AC current transformer it requires a "changing" magnetic field to transfer energy from one winding to another. DC current although developes a magnetic field doesn't change once established.
 
   / Electrical Limitations #18  
Indeed it must be a Hall effect sensor with the higher end clamp multimeters that measure DC. I've seen the iron vane type of clamp meter for DC, but my Fluke 337 doesn't have any of that 'hardware' in it. From what I can find, those are the only two ways for non-contact DC current measurements.
 
   / Electrical Limitations #19  
We certify DC and AC clamps. We test them from 10 mA up to about 10,000 amps.. Just depends on how accurate you want to pay for.
To the OP doesn't your alternator have a plate on it telling the output current rating? Or if you have a fuse block see if there is a master fuse in line. Say if it is rated at 35 amps then your alternator is going to be rated around 30-35 amps. If you want to conserve a bit of reserve current go with LED lights which will draw a lot less current. But they will draw more $$$ from your wallet.
 
   / Electrical Limitations #20  
What is the best way to determine the electrical requirement of the tractor "as is", and then figure out how much more you can add to it w/out utilizing alternator 100% or more, and draining the battery, and potentially ruining the alternator.

Looking to add some work lights, and maybe a CB, and I'd like to know how much I have to work with.

What about adding a second battery for when say using a spot light at night for short periods?

All accessories would run off a distribution block that connects directly to the battery.
:thumbsup:

I'd limit myself to 80% of the rated output of the alt for continous loads. Amperage gauge aft of alternator will show total charge output. get all yer tractor loads going, read gauige, look up alternator specs.. see how much freeplay you have till you hit 80%.. whatever that number is is safe for a continous load. You can exceed that of course.. but I would not do it for long durations so that you are exceeding 80% rated output on the alt for too long.

soundguy
 

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