Potential Difference

[C2]

The scene is an ideal configuration without leaks, etc...

I was discussing house voltage with someone and their position is that if your home is the only home on a transformer, then you can disconnect the main power lines comming to the house and touch any one of them without problem, even if you are solidly grounded. He says you cannot get any power out of just one of the wires, even if you have a really good earth ground rod.

He says that the two high voltage lines have a large potential difference between them, something like 1.3kV. He says that the potential difference between them and you is very small and that you should, in theory, be able to touch any one of them without problem. He said the only reason for problem is that there are faults in the system.

He made the analogy with car batteries. If you just had access to only one terminal, you could not get any power out of the battery.

 

[Captain Kilowatt]

Tell him to try it. Put 911 on standby however. Your friend is full of it. When I first built my house I WAS the only house on the utility transformer.Trust me you CAN get power from one wire. :shock: It is AC and uses the ground as a referance.The neutral wire is actually grounded but the other wire is hot.

BTW there is a lot more than 1.3 Kv on the primary. Most areas use around 7200 volts and some newer areas use up to 12,000 volts around here.

 

[ken white]

He is talking about an isolated, or floating system, and in an ideal system this would be true because there would not be a path for current to flow.

However, since all AC electrical distribution systems are grounded for safety and reference purposes, there would definately be leakage current between one of these grounds and the earth where you are standing at some level. If your body resistance is low due to external factors, it only takes 100 mA to kill you. This means a fairly low voltage can kill you.

 

[C2]

That is what he was talking about and said that the power companies do try to isolate their systems from ground (not including service points). At least their generating plants are isolated.

 

[Captain Kilowatt]

OK you are talking about a perfect non existant situation then. In that case I suppose it could be true but I am not willing to test it out.

 

[C2]

OK, one more angle from the real world.

Would a house work just as well if the main neutral supply line was cut?

(given good earth grounding at the box)

 

[lords]

why we talking about volts???
its amps that kill not volts and AC 25 amps can fry you...
if thats the case pic tubes can fry you and they don't,(thats volts) they just raise the hair on the back of your neck ..lol


If your body resistance is low due to external factors, it only takes 100 mA to kill you. This means a fairly low voltage can kill you

might be true or not, for now thats hearsay!
unless you have great news about this...that means a CB(driver and final biasing) can kill a serviceman with a cold? or a low body resistance


C2 , think about this...unless you touch both wires in your house your safe...even if you did get a shock it will throw you off of it on a regular 120AC 10-20 amp service...my departed mothers X-husban is a line man and has no problems...been doing it for 30 years..next

any one want to challenge me on this ...pay me for my time I will show you by making a video changing ,light fixture,socket touching each wire

I paint and do new construction with sprayers and wire a 30amp breaker right inline of the fuse box and have no problem touching
each line coming in the house for this 30amp service to run the sprayer...hell I got better shocks from KV picture tubes and flybacks (high voltage transformer in a TV set)...

anytime any day...seeing though proof seems to quiet down most posts!

 

[Captain Kilowatt]

Lords, just because you obviously have a high natural body resistance does not mean what you say is fact as applied to everyone.For something to be FACT it must apply in ALL cases. I for one have a natural low body resistance,in the order of 20-30 thousand ohms from left hand to right, and that's on a good day. It is even lower if I am a bit sweaty.I can feel leakage currents before most can.I get hammered off the 120 line. Boy and to think I used to work with up to 5000 volts DC. As far as the tired old statment that it is the current that kills you not the voltage well that is because there is no definate applied voltage that will kill you. Everybody has a differant body resistance and therefore everybody requires a differant applied voltage to achieve that fatal current level.BTW yes, a TV pix tube can kill you.The charge is around 30,000 volts and given the right situation it can be fatal.

 

[lords]

and given the right situation it can be fatal.all of it


erm, forgot to add that...lol
you need any ohms pills?
mines 300.0K rms not stable its rising
I know what you mean,,dam trying to make a quick buck..you messed it up..lol
o'well stay tuned to next week on HOW TO GET RUN OVER BY A CAR THE SAFE WAY!

 

[Captain Kilowatt]

Is that "HOW TO GET RUN OVER BY A CAR THE SAFE WAY!" or How to get run over by a car AT the Safeway"

 

[lords]

lol true that..course just last weekend a lady ran over 3 pumps at our local Cigo Gas station...now going pumpless...and just think she wasn't drunk just bad driving took all 3 out of the ground 1 shot!

WE NOW RETURN YOU TO YOUR NORMAL PROGRAMING STATION

 

[ken white]

why we talking about volts???
its amps that kill not volts and AC 25 amps can fry you...
if thats the case pic tubes can fry you and they don't,(thats volts) they just raise the hair on the back of your neck ..lol


If your body resistance is low due to external factors, it only takes 100 mA to kill you. This means a fairly low voltage can kill you

might be true or not, for now thats hearsay!
unless you have great news about this...that means a CB(driver and final biasing) can kill a serviceman with a cold? or a low body resistance


C2 , think about this...unless you touch both wires in your house your safe...even if you did get a shock it will throw you off of it on a regular 120AC 10-20 amp service...my departed mothers X-husban is a line man and has no problems...been doing it for 30 years..next

any one want to challenge me on this ...pay me for my time I will show you by making a video changing ,light fixture,socket touching each wire

I paint and do new construction with sprayers and wire a 30amp breaker right inline of the fuse box and have no problem touching
each line coming in the house for this 30amp service to run the sprayer...hell I got better shocks from KV picture tubes and flybacks (high voltage transformer in a TV set)...

anytime any day...seeing though proof seems to quiet down most posts!

Lords, the military considers anything greater than 30 volts as dangerous. When the body is depleted of electrolites, and covered in a heavy, salty sweat, the body resistance has been measured as low as 300 ohms.

Feel free to ignore the voltage around you since you have a high body resistance under all conditions.

Darwinism at its finest...

Even though its current that kills you, current won't exist without a difference in voltage potential.

I personally don't like to test my fate by touching hot wires...

:shock:

 

[ken white]

OK, one more angle from the real world.

Would a house work just as well if the main neutral supply line was cut?

(given good earth grounding at the box)

Not if the house has ground fault interupters installed, then nothing will work.

The neutral and ground wire are both bonded togther back at the service entrance and provide 2 separate paths back to the panel. The neutral carries the normal/system current, and the ground should only carry fault current.

So, equipment that is designed and operating correctly will probably not work if the neutral is cut, while faulty or non-safety type equipment may or may not work.