so that leaves me with more doubts, like a million of them, like then what if 450 CCA are on ground and the starter motor positive cable? that wont generate a electro magnetic field like the one you mencioned and probably burn things up? not trying to discuss with you, just want to order the things on my mind

OK let's forget the whole CCA (Cold Cranking Amps) thing since a battery CCA rating has nothing to do with it. CCA is a rating used in the battery industry to define a battery's ability to start an engine in cold temperatures. The rating refers to the number of amps a 12-volt battery can deliver at 0°F for 30 seconds while maintaining a voltage of at least 7.2 volts. That aside, when I start a car or truck and engage the starter motor the starter motor is a high current DC motor. The common method to actually measure the starter motor current is using a simple clamp on current meter. Clamp On current meters can measure AC current, DC current even true RMS AC current. So I place my clamp on meter on that large heavy cable running from Battery + (Positive) terminal (Negative if you prefer) to the starter and crank the engine. At no point is my current meter actually touching anything, it's just there. So how does it read current? How does a Hall Effect sensor read current? They are not wired in series with the load so how do they work? Now want to take bets on a magnetic field around a current carrying conductor? Got an old magnetic compass? Lay it beside a current carrying conductor let me know how that works out for you.

A million doubts is fine like a million questions. You start with number One and work from there.

Ron

 

yeah i think i know how to use a clamp meter, but why those hundred amps can´t damage things too like the welder? is because of the distance of the ecus? in some cars they are just behind the battery, or because the welding process requires more voltage?. remember english is not my first lenguage and im triyng to express myself (google translator make mess when i try to translate your english to my lenguage so im not using it in reverse haha)

 

True, there is a lot of things we are exposed to in our modern society that may or may not have harmful effects. High voltage lines, cell phones against the side of our heads next to our brain, etc. I would not be surprised if high EM fields might have detrimental effects on biological systems, whether those fields be static or dynamic (i.e. EM waves). Consider the nerve cells that go from the brain, down the spinal cord. Not to many people are aware of the fact that these cells are the longest in the human body as the axon of the cell is many feet long; Yes very thin but extremely long. Being the wavelength of the field in compatible with these cell lengths, I would not be surprised if such fields interfere to some degree with proper functioning of the nervous system and who knows what the long term effects are.

Certainly there are, and have been for a while, people raising red flags about the electrical fields under power lines, as well as about the magnetic fields around big transformers. so the concerns have been noted by some and refuted by others, and the truth is not visible.

 

yeah i think i know how to use a clamp meter, but why those hundred amps can´t damage things too like the welder? is because of the distance of the ecus? in some cars they are just behind the battery, or because the welding process requires more voltage?. remember english is not my first lenguage and im triyng to express myself (google translator make mess when i try to translate your english to my lenguage so im not using it in reverse haha)

A few post back I mentioned Volt per Meter. You may want to read more about that here. Next you may want to read more about Induced EMF and Magnetic Flux. Much of this is much too lengthy to get into a post on the forums.

Next, I am not a welder. I have worked with many large welding machines but I am not a welder. That said in the welding process the voltage as measured across the actual arc is not very high. The current is what is high. I have seen TIG welding machines where the actual arc voltage is between 13 and 15 volts with the current at 200 amps or greater. All in all a current carrying conductor will have a magnetic field around it. You can also try a Google of "right hand current rule" which you may fine interesting.

Your English id just fine.

Ron

 

Sometimes I am given safety precautions relative to things that I am not familiar with. and sometimes warnings about hazards where I am not aware of the mechanism of harm from such a hazard. The fact is that just because the exact mechanism of the hazard is not clear to me does not mean that it does not exist. That has included electrically "hot" hardware that certainly should not have been hot, and high pressure leaks that should not have been leaking, and a gas charged accumulator that should not have burst when it did, and also an area where there was no oxygen, because of a gas leak.
My point being that not every hazard is clearly visible or easily known.

You keep going back to this. At what point was the existence of the hazard disputed? This thread is about getting a better understanding of the hazard and auditing the prevailing theory on the best way to mitigate it. I do not understand your objection. You're arguing against a premise that you contrived in your own head.