live supply

[wattsup]

If you have a live supply but no neutral, in effect just a phase, why can't you utilise and make your own neutral / earth. Assuming the earth/neutral path would suffice...this isn't breaking the meter reading thread posted elswhere.

For instance I can pick up a live, make a path to earth quite easily, 230v to earth no problem...

N&E are combined at source anyhow. Where's the problem with that scenario...;

 

[Des 56]

My first thought (as always ) would be the kettle

Getting low readings on a TT are difficult,150 ohms being pretty good

If you was to boil that kettle combining the kettles resistance and the earth resistance it would allow so little current flow that you wouldn't be making me a cup of tea any time soon

 

[wattsup]

Lol..., I will boil your kettle easy. In almost any soggy soil...try it. Throw your meter in the bin it is flawed

 

[uksel]

in a practical sense he's right, you would need a very good path through earth in order for anything to work

the earth path would be a resistance in series with the appliance.

the other reason is that in this instance you would be relying on your earth as the neutral, meaning current flow = BAD

this would also mean no EEBADS (Auto-Disconnection of Supply)

or are you asking why this wouldn't comply with the regs?

this being the case the supplier would fail to comply with the electricity supply regulations. quoted:

The supplier shall, in the design, construction, maintenance and operation of his system, take all reasonable precautions to ensure continuity of the supply neutral conductor

 

[lloyd1980]

if they are always combined at source then how come sometimes its a tncs (combined) fair enough then others a tns (seperate and sweated onto the outer sheath)
how on earth are you going to make ur own neutral in a tns supply situation?

 

[wattsup]

(seperate and sweated onto the outer sheath)
No differnce really, just more robust cable now pvc, rather than lead sheathed which at the time was best available, being lead sheathed meant sweated earth on to sheath....nowadays no need pvc cable feed, but back at point of supply no difference

 

[Darkwood]

In practice creating a return path with earth will work but it comes with heavy safety risks as say you had a broken return earth then effectively anything connected to earth could become live!! like radiators etc and just waiting for the unsuspecting person to touch them and make the circuit.
This is why tncs systems employ multiple earthing on the supply earth/neutral to ground as many times as possible so a break in the supply combined earth/neutral wont make all the earthed metal in the house live as alternative paths would be available.

 

[wattsup]

it's quite simple to make your own n supply, assuming you have a good earth. In reality a neutral is not required whatosoever...not safe, but appliances would still work, where e is the path rather than n. Hence they are seperated at the consumer end...normally.

Not safe but that was not the question. also neutral to earth faults can be the most difficult to diagnose especially in industrial situations where no rcd's are used

 

[lloyd1980]

im only concerned with the stuff after the meter sorry
have no interest in the supply regs

 

[wattsup]

darkwood is right, in effect a borrowed n but in reality is an earth (radiator)...causes big probs

 

[uksel]

im only concerned with the stuff after the meter sorry
have no interest in the supply regs

you would be if you had no neutral

 

[wattsup]

Some countries still use this method of wiring, I know they do in some villages in indonesia, in fact they did in thailand until about 1980 ish....extremely dodgy....but it works (nothing to do with fiddling the meter -

as uksel was infiring, neutral earth faults are the most dangerous, because in effect they are as one. You can lose the neutral yet everything still works because of the fault.
Not so much these days because of rcd's etc....but many are still sitting on dodgy stuff. I know it takes a series of of events to create a shock hazzard, but nearly always its down to a neutral fault. Because the fuse will not blow, no fault live to earth....and try explaining that to a banker

 

[ian.settle1]

in a practical sense he's right, you would need a very good path through earth in order for anything to work

the earth path would be a resistance in series with the appliance.

the other reason is that in this instance you would be relying on your earth as the neutral, meaning current flow = BAD

this would also mean no EEBADS (Auto-Disconnection of Supply)

or are you asking why this wouldn't comply with the regs?

this being the case the supplier would fail to comply with the electricity supply regulations. quoted:

The supplier shall, in the design, construction, maintenance and operation of his system, take all reasonable precautions to ensure continuity of the supply neutral conductor

Thought this term became defunct in July 2008

 

[solo2771]

If you have a live supply but no neutral, in effect just a phase, why can't you utilise and make your own neutral / earth. Assuming the earth/neutral path would suffice...this isn't breaking the meter reading thread posted elswhere.

For instance I can pick up a live, make a path to earth quite easily, 230v to earth no problem...

N&E are combined at source anyhow. Where's the problem with that scenario...;

Reminds me of my dad (82 n0w) he wanted a light couple of hundred meters up his garden so he could feed the geese so ran a single phase wire up to a single bulb and then from the neautral terminal ran a wire to a rod in the ground and that was it done lol. (don't think that would pass 17th edition inspection)

 

[bugsy]

But where are you going to find 230v flapping about without a return path in the first place