Electric shock treatment

[tim west]

To all those trying to be clever, the word potential means a hypothetical or possible event may or may not occur but it has the "potential" to.
In relation to voltage there is a potential for "230 volts"

Anyway ive just got a call about a power failure and can i sort it out as the other "spark" didnt have a clue

 

[ebee]

LOL.
Ok I`ll admit it.
I liked that

 

[ricicle]

To all those trying to be clever, the word potential means a hypothetical or possible event may or may not occur but it has the "potential" to.
In relation to voltage there is a potential for "230 volts"

Anyway ive just got a call about a power failure and can i sort it out as the other "spark" didnt have a clue

No one is trying to be clever Tim, but a degree of clarity is needed as your posts are slightly ambiguous.

 

[ebee]

So right then.
Your term voltage potential means that potentially a voltage could exist there although at present it might not actually do so.
Wheras when we say potential difference we mean difference in electrical potential (potential not meaning hypothetical in this use of the term but something that does actualy exist and as such we could measure it).

 

[tim west]

To all those trying to be clever, the word potential means a hypothetical or possible event may or may not occur but it has the "potential" to.
In relation to voltage there is a potential for "230 volts"

Anyway ive just got a call about a power failure and can i sort it out as the other "spark" didnt have a clue

No one is trying to be clever Tim, but a degree of clarity is needed as your posts are slightly ambiguous.

ok apologies as i have to type so fast to keep up

 

[tim west]

So right then.
Your term voltage potential means that potentially a voltage could exist there although at present it might not actually do so.
Wheras when we say potential difference we mean difference in electrical potential (potential not meaning hypothetical in this use of the term but something that does actualy exist and as such we could measure it).

grrrrr thats the crux of what i was saying if i read you right.

pd is measurable whereas a voltage potential can be anything up to the voltage at the source its connected to, you cannot be certain of this voltage as its got no reference but has the ability to achieve the source voltage when finally connected into a circuit.

hoping and praying that thats not too ambiguous a reply.

 

[ebee]

Another example.
I envisage we all go away knowing we were correct but also the opposing view was also correct because of the different meaning of the same term within different contexts.

Back to the three phase example.
Lets say two switches in one enclosure with the switches on different phase (something we normally try to avoid but here for illustration purposes).
Ph 1 & Ph 2 for example.
Controlling two lights.
With both switches open the output side is at 0V (N voltage thru the lighting filament which is at earth potential)
Ph1 switch closed the output is at 240 in respect to to the output for the other light.
Ph 2 switch closed (Ph 1 back to open position) then 240 again difference between the two outputs.
Both Ph 1 & Ph 2 closed then 415 now exists between them both.

 

[ebee]

Dare I say,
voltage potential is introduced by stray resistance/capacitance/inductance on a circuit board etc that could introduce a potential via something once it is actually connected to a source yet at the moment (say still on the bench and waiting to be inserted) has no PD?

 

[Softus]

the word potential means a hypothetical or possible event may or may not occur but it has the "potential" to.

If that's all you've been trying to say all along, then (a) you've failed miserably, and (b) it's a completely pointless term to use.

Potential, using the plain language definition, could mean that there are no volts, or that there are some volts. Either way, the value of that potential difference can be measured. By you, or by me, or by anyone with a galvanometer.

In relation to voltage there is a potential for "230 volts"

Except for you on this topic, can you explain why nobody on the forum has ever claimed that this a common term in electrical parlance? Or, if you think they have, who and when claimed it?

 

[ebee]

Yipee,
In consolation we all use the same term sometimes to mean different things.
In normal everyday sort of use some things might mean one meaning (or two or more) but in technical terms depending upon the particular discipline mean something different.
Easy example "Fabulous" as in a Fable = not true, everyday use Good great (too good to be true).
Legal meanings and common meanings of words/phrases often differ greatly.

Case in point , electricians often argue about Spurs (no not cowboy ones).

A spur off a ring final is purely a radial connection to that ring, however it is quite common to reffer to a switched fused connection unit as a spur.
Arguements proliferate over this.

Similarly the term "Live" often to most folk (including a lot of electricians mean phase (240 to E & N)) but it actualy means a conductor that normally carries current as its intended function (with one exception) , therefore N is a live conductor.

 

[tim west]

Another example.
I envisage we all go away knowing we were correct but also the opposing view was also correct because of the different meaning of the same term within different contexts.

Back to the three phase example.
Lets say two switches in one enclosure with the switches on different phase (something we normally try to avoid but here for illustration purposes).
Ph 1 & Ph 2 for example.
Controlling two lights.
With both switches open the output side is at 0V (N voltage thru the lighting filament which is at earth potential)
Ph1 switch closed the output is at 240 in respect to to the output for the other light.
Ph 2 switch closed (Ph 1 back to open position) then 240 again difference between the two outputs.
Both Ph 1 & Ph 2 closed then 415 now exists between them both.

Its not the same term though i've been trying all along to differenciate between the two terms, unsuccessfully by the look of it

the three phase example has different reference points as stated by yourself.
both open and the lamps become a parallel series open network with earth as the only reference both filaments and indeed all the wiring in this network are at 0v potential. and before bernard joins in, bar the electrical noise of the earthing system and the differing resistance of the wires. we'd say its at earth potential or at 0v potential note 0v is also termed a voltage potential albeit 0 volts dont mention pd yet, theres no circuit both switches are open.

the 240v and 415 volts readings are using either an earth connection or an out of phase connection to achieve a potential difference when switches are closed ie the 415 potential is only read between phases or only across both lamps if the earth connection is disconnected but leaving both lamps in series, the earth being rmoved changes the network from parrallel series to series. For everyones sake lets keep the examples simple though

 

[ebee]

Yes pretty much so, but the N (E) needn`t be removed both outputs from the switches would be at 415 to each other and still each at 240 to N (E).
Thats why we try not to do it as 415V is more dangerous (potentially of course LOL) than 240

 

[tim west]

Dare I say,
voltage potential is introduced by stray resistance/capacitance/inductance on a circuit board etc that could introduce a potential via something once it is actually connected to a source yet at the moment (say still on the bench and waiting to be inserted) has no PD?

yes if the gnd isnt connected then yes but with pcb's its tiny currents can flow with millivolts or even microvolts so theres not to say that a return path is not there as you state stray paths may exist?

 

[tim west]

Yes pretty much so, but the N (E) needn`t be removed both outputs from the switches would be at 415 to each other and still each at 240 to N (E).
Thats why we try not to do it as 415V is more dangerous (potentially of course LOL) than 240

yes agreed but i wasnt suggesting you couldnt read at that point, it would take too much typing to categorise every test point hence i just gave an example.

its the classic two cookers scenario that we were taught at college in my days a dropped earth or neutral can lead to "potentiallyTM" dangerous situations.

 

[ban-all-sheds]

Whilst the consumer sparks amongst you may be having difficulty with this, electronics engineers shouldn't be.

I agree - not if it's a term that they've invented that has a definition that they've invented as well.

A potential difference doesn't actually exist until you use it in some way? It's all starting to sound a bit like the argument over whether a tree falling over in a forest where no creature hears it makes a noise.

Differences of voltage potential between physically neighbouring components on a board which are NOT on the same circuit and subject to different potential difference is a major design issue for real time systems circuit designers ... Particularly in the aerospace industry.

If they are not on the same circuit, and do not have a shared reference point of any sort, then where is the potential for there to be a potential difference between them?