Electrical Limitations

[Redneck in training]

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.

 

[Redneck in training]

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.

Here is one that measures both AC and DC.

Fluke 336 Clamp Meter

 

[LD1]

Here is one that measures both AC and DC.

Fluke 336 Clamp Meter

That is the one I have. See my post #5

 

[Craig Clayton]

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

 

[Craig Clayton]

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

 

[frischtr]

-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.

 

[RPW]

-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.

 

[frischtr]

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.

 

[Treemonkey1000]

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.

 

[Soundguy]

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