Ground Clamp Differences

[k0ua]

I am an electrician by trade and am assuming you have some relation to the trade, having said that I have to say for all intensive purposes electricity does attempt to take the shortest path to ground any other paths are so inconsequential as to be considered non existant. otherwise people would get a lot more shocks than they do.

Here is my take, you want a good gound clamp? Find one with a good spring and the more contact surface area the better. want a good ground 10 seconds with a flap disk will take care of that before you clamp your ground on. Oh and keep it cleaned up any arc pitting from iffy connections affects continuity too. Thats my say!

Thank you
Thank you very much

How do the electrons "know" which is the shortest path? do they measure it first? and is the shortest (distance )path the lowest resistance in all cases? answer, NO. Electrons flow in all conductive paths, the resistance of each conductive path determines the amount of current that will flow in that path. Ohms Law E=IR you can calculate the amount of current if the (E Electromotive force) is known and the (R Resistance) is know or can be measured. you will then know the (I current in Amperes)
Now before someone mentions Capacitive or Inductive Reactance in AC complex circuits or even skin effect in RF circuits, this is not what we are talking about here. We are talking about DC here to make this point. Lets say its a cool day and you are pretty dry, and you touch the positive terminal of a 12 volt battery on your tractor that is powering your lights. The lights are going to be drawing around 10 amps of current, a pretty sizable amount. Your skin even if it was pretty damp is going to limit the current to a very small amount at 12 volts. probably in the neighborhood a few milliamps or 10s of milliamps due to the pretty high resistance of your skin. Now do the exact same thing to a 48 volt electic fork truck this time you are going to feel it, as the current is 4 times more, and if you are really salty sweaty you are going to feel it even more as your resistance is less and the current will be much higher.. Remember the fork truck is still lighting those lights, but you got shocked, how can that be? "electricity always takes the path of least resistance or electricity always takes the shortest path right" bull-feathers electricity takes all paths. the path thru the copper wiring powering the lights with a very high current and the path thru your sweaty skin with much much less current. (but still enough for you to feel. Or how about this one..open your breaker box, take your shoes off have sweaty feet and stand on the damp concrete floor of your shop. Now have all the lights, air conditioning and everythig else in the shop on. maybe the load could be pulling lets say 50 to 100 amperes from the 240 volt mains. A lot of current going thru that low resistance copper wire, and your little body has a lot of resistance compared to copper wire even sopping wet. but let me tell you what will happen when you touch even 1 phase of that entrance circuit.. you are likely to be killed. or at least have the holy.... knocked out of you. But the current flowing in you will be very small compared to the current flowing in the copper wires, thru all the loads (appliances) back to the neutral. so why did not the electrons take the shortest (least resistance ) path ? well they did, but they also took the relatively high resistance path also (you). If you were very very dry, (this is a cold winters day in canada with the humidity around 10%) and you touched 1 of the phases. you may just get a tingle or little jolt.. because your resistance is very very high. but you still got some of the electrons. Because Electrons dont know anything, about paths, or what resistance those paths have. They flow in "All Paths" end of book.

James K0UA

 

[chad22]

I'm no expert, but I think it's Bull when they say grounding prevents shocks.

Why I say that is. I've gotten shocked by a grounded electric motor when I touched it.

The hot wire had come loose and was touching the metal. Yeah the electricity probably took the path to the ground through the ground wire. But it also took it's path to the ground through me.

Don't be fooled to thinking the ground wire is gonna completely protect you.

Chad

 

[Grayson Klassen]

LOL

AH K0ua I looked at your profile and saw engineer and it all made sense, it was either that or highscool science teacher.:laughing:

I could point out that it is all theoretical anyway as neither electron nor conventional current flow are anything but really convenient models and until we can watch electrons actually jump they are still for the most part only proven mathmatically and not irrefutable.

Tell me this why is it critical that parallel conductors be as close to the same legnth as possible and what is the danger if they aren't?

I hoped my last bit was sufficient to say one ground is enough just make it a good one.

As for Chad if you got a shock off a grounded motor it either was a poor ground or you were a better one (you know sweathy palms stanking in a puddle with bare feet ask K0ua). The ground is not only your best defence it is usually your only defence as neutrals are not case connected. Trust me you are way safer with than without.

Back to K0ua this is all in fun so if I offend my apologies:laughing::thumbsup:

 

[Gary Fowler]

I am not an electrician, but am a pretty fair welder and have been doing it for over 40 years. A ground doesnt have to be close to your work unless you are welding on equipment with bearings in it, then the accepted practice is to put your ground on the away side from any bearing so the current travels toward the ground. The resistance in the cable would make you have to turn up the amps as you moved away from the welding machine with you electrode. Most construction welding machines have only 50 feet of ground and Miller 8 bank welders can be universally grounded from one point for all machines and they still work well as far as welding goes. As long as your ground point is good and not arcing, you can be 1000 feet away and weld will be just like you are at the machine with the exception that you may have to run the setting on 300 amps to get 100 at the stinger end. The analagy of touching the battery post and stealing current from the lights is nothing more than adding another circuit. You can think of it as the power grid and you can run as many circuits as your want from it till it runs out of power.

 

[k0ua]

The analagy of touching the battery post and stealing current from the lights is nothing more than adding another circuit. You can think of it as the power grid and you can run as many circuits as your want from it till it runs out of power.


Exactly. That is the point I was trying to make with the long winded post. As everyone knows we can have parallel paths for the electrical service and it all works fine. The overall load resistance from the point of view of the source is constantly lowered as you add more loads. And in each load the current will be following Ohms law.. It is not just a good idea, it is the Law:laughing:

James K0UA

 

[grsthegreat]

I'm no expert, but I think it's Bull when they say grounding prevents shocks.

Why I say that is. I've gotten shocked by a grounded electric motor when I touched it.

The hot wire had come loose and was touching the metal. Yeah the electricity probably took the path to the ground through the ground wire. But it also took it's path to the ground through me.

Don't be fooled to thinking the ground wire is gonna completely protect you.

Chad

doesnt make sence. if the hot wire had come loose and was touching the metal, and if the metal of the motor was properly grounded, then the return path would have opened the circuit (thrown the breaker).

The motor was not grounded. your touching it grounded it.

 

[Soundguy]

LOL

AH K0ua I looked at your profile and saw engineer and it all made sense, it was either that or highscool science teacher.:laughing:

you say engineer like it's a bad thing...


soundguy

 

[Grayson Klassen]

you say engineer like it's a bad thing...


soundguy

I banterred whether I should reply to this or not.

I have been an industiral electrician for a lot of years and haven't been on the tools since 1999. Since then I have run a couple of maintenanace departments, worked as a consultant in the oil and gas industry, and my current roll as process control manager. I have worked in many industries and have a lot of experience. As you can imagine in those roles I have dealt with many an engineer. Now you have to take this as an attempt at humor with one foot solidly grounded in reality.

1. For every good engineer there are two bad ones. Look left look right if you don't have a dummy on both sides guess what...

2. What do engineers use for contraception.....their personalities.

okay now that I got that out of the way as I said I have worked for and rode herd on many engineers. I know some really good engineers, I also know some stuffed shirts who know diddly and hide behind white paper. Just cause it works on paper doesn't mean it works in the real world.

Being an engineer isn't a bad thing many is the day I wish I had gone back to school and become one. I didn't but as I am very good at what I do which is automation I have done well. To all the good engineers cudos, to the over educated stuffed shirts, out of the way leave it to the pros.

I hope that answers your question without seeming like I am an arrogant goof. Some people call a spade a spade, I call it a shovel and hit people over the head with it LOL

 

[Wyobuckaroo]

In this part of the country, the difference between those clamps is...........


About $8.00

(bwahahahahhha, snicker, chuckle, snort, gefaw)

Wyo

 

[Soundguy]

10$ delta at tsc..


soudnguy

 

[Grayson Klassen]

In this part of the country, the difference between those clamps is...........


About $8.00

(bwahahahahhha, snicker, chuckle, snort, gefaw)

Wyo

As in may posts the original question is no longer the point:laughing:

 

[k0ua]

I banterred whether I should reply to this or not.

I have been an industiral electrician for a lot of years and haven't been on the tools since 1999. Since then I have run a couple of maintenanace departments, worked as a consultant in the oil and gas industry, and my current roll as process control manager. I have worked in many industries and have a lot of experience. As you can imagine in those roles I have dealt with many an engineer. Now you have to take this as an attempt at humor with one foot solidly grounded in reality.

1. For every good engineer there are two bad ones. Look left look right if you don't have a dummy on both sides guess what...

2. What do engineers use for contraception.....their personalities.

okay now that I got that out of the way as I said I have worked for and rode herd on many engineers. I know some really good engineers, I also know some stuffed shirts who know diddly and hide behind white paper. Just cause it works on paper doesn't mean it works in the real world.

Being an engineer isn't a bad thing many is the day I wish I had gone back to school and become one. I didn't but as I am very good at what I do which is automation I have done well. To all the good engineers cudos, to the over educated stuffed shirts, out of the way leave it to the pros.

I hope that answers your question without seeming like I am an arrogant goof. Some people call a spade a spade, I call it a shovel and hit people over the head with it LOL

Well Grayson, I have only been an Engineer for 11 years. 21 years before that as a Technician in the telephone industry. Before that a Technician in a 2 way radio shop (General Radiotelephone ticket) and an Amateur Radio Operator (Extra class) for 40 years this summer. For what little all that is worth. Yes I am a nerd, but I have never relied on my personality for contraception. But anyway, I have picked up a few things along the way but have never considered my self a "stuff shirt" more like a " tee shirt". But I tell you what, if you would like to learn a little more about some of the more interesting electrical phenomena like lightning, give me a call some time, as I believe I could tell you a thing or two.

Best Regards
James K0UA

 

[Soundguy]

de ke4rrd


73's

soundguy

 

[k0ua]

de ke4rrd


73's

soundguy

Living in Florida, I bet you know a thing or two about lightning!

73
K0UA

 

[Soundguy]

just a bit..

pine trees love it..


soundguy

 

[Grayson Klassen]

Well Grayson, I have only been an Engineer for 11 years. 21 years before that as a Technician in the telephone industry. Before that a Technician in a 2 way radio shop (General Radiotelephone ticket) and an Amateur Radio Operator (Extra class) for 40 years this summer. For what little all that is worth. Yes I am a nerd, but I have never relied on my personality for contraception. But anyway, I have picked up a few things along the way but have never considered my self a "stuff shirt" more like a " tee shirt". But I tell you what, if you would like to learn a little more about some of the more interesting electrical phenomena like lightning, give me a call some time, as I believe I could tell you a thing or two.

Best Regards
James K0UA

LOL well well well

Never forget that we can each learn from each other in just about all cases. I was not so silly as to say all engineers are stuffed shirts only that it was a possibility LOL. I don't even think I called you a stuffed shirt.

You never answered my question about parallel current carrying conductors and the length concerns.:thumbsup:

 

[k0ua]

Tell me this why is it critical that parallel conductors be as close to the same legnth as possible and what is the danger if they aren't?

Please tell me the context here. Are we talking a parallel transmission line here as in RF energy transmission? Such as 450 ohm open wire line? or something else? Telephone twisted pair longitudnal balance problems (60 hz pickup? Unequal currents due to resistance differences? I don't understand the question.

James K0UA

 

[Haywire]

For what it's worth, I ordered the one on the left.

Ian

 

[dcyrilc]

For what it's worth, I ordered the one on the left.

Ian

:thumbsup::thumbsup:

Let us know how you like it.

 

[Soundguy]

on a welding lead I doubt it makes a (tangible) difference.. that is.. if we are talking a spare grund lead.. etc..


soundguy

Tell me this why is it critical that parallel conductors be as close to the same legnth as possible and what is the danger if they aren't?

Please tell me the context here. Are we talking a parallel transmission line here as in RF energy transmission? Such as 450 ohm open wire line? or something else? Telephone twisted pair longitudnal balance problems (60 hz pickup? Unequal currents due to resistance differences? I don't understand the question.

James K0UA