3 phase head in a single phase meter Uk energy networks saying I'm not 3 phase

[HappyHippyDad]

Nothing unlikely about it at all as throughout CENELEC countries this is known as a 400/230V supply, so 400v is the correct designation of that voltage.

I realise its the 'correct' voltage, but how often do you measure a single phase supply and it is 230? It is usually more as we seem to be a 230V country on paper only, so i am assuming most 3 phase supplies are still 415V.

 

[Risteard]

I realise its the 'correct' voltage, but how often do you measure a single phase supply and it is 230?

Actually here, frequently. It has always been 230V here as the south was traditionally 220V and Britain traditionally 240V.

Regardless, 400V and 230V are the only correct way to describe those voltages. It is a nominal voltage - voltage fluctuates all the time. So as long as it is within the range of +10%/-6% then that is what it is.

 

[davesparks]

Nothing unlikely about it at all as throughout CENELEC countries this is known as a 400/230V supply, so 400v is the correct designation of that voltage.

Be has stated that the voltage was measured as being 400V, also that he is within a few metres of the substation. The voltage should be a lot nearer 433 as all uk distribution transformers output 250/433 regardless of what the nominal is.

If it was measured at 400 then it suggests the substation is running at its max capacity already

 

[Risteard]

Be has stated that the voltage was measured as being 400V

But that is how the voltage measured would be described.

I wouldn't say I had measured 233V at a terminal - I would say I had measured 230V. Likewise, I wouldn't say I had measured 408V - I would say 400V.

 

[davesparks]

But that is how the voltage measured would be described.

I wouldn't say I had measured 233V at a terminal - I would say I had measured 230V. Likewise, I wouldn't say I had measured 408V - I would say 400V.

Then that would be untruthful and incorrect. A measured value is exactly that, the value which has been measured. It is different to the nominal value which is the theoretical or named value.

 

[davesparks]

I realise its the 'correct' voltage, but how often do you measure a single phase supply and it is 230? It is usually more as we seem to be a 230V country on paper only, so i am assuming most 3 phase supplies are still 415V.

It is not correct, it is nominal, that is to say it is the voltage which has been named as the theoretical value.
The actual voltage which all public network distribution transformers in the UK output is 250/433V, this is a material fact which will not change.

 

[Risteard]

Then that would be untruthful and incorrect. A measured value is exactly that, the value which has been measured. It is different to the nominal value which is the theoretical or named value.

No, because the voltage must be recorded as the nominal value. So by measuring 400V that is anywhere between +10% to -6%. It is still 400V and should be described as such.

The measurement is merely to confirm that there is 400V there, and not to see whereabouts it is within the accepted tolerance for that nominal voltage.

Meters have an accuracy within a certain percentage too so who is to say how accurate your reading is?

 

[davesparks]

No, because the voltage must be recorded as the nominal value. So by measuring 400V that is anywhere between +10% to -6%. It is still 400V and should be described as such.

The measurement is merely to confirm that there is 400V there, and not to see whereabouts it is within the accepted tolerance for that nominal voltage.

Meters have an accuracy within a certain percentage too so who is to say how accurate your reading is?

That is a ridiculously blinkered approach.
This is supposed to be a technical trade and electricians should be able to understand the basic scientific principles behind it.
If you are reporting a measured value then it must be the value which was measured, if you are reporting a nominal value then it should be the nominal value.

 

[Risteard]

That is a ridiculously blinkered approach.
This is supposed to be a technical trade and electricians should be able to understand the basic scientific principles behind it.
If you are reporting a measured value then it must be the value which was measured, if you are reporting a nominal value then it should be the nominal value.

All he asked for someone to check was whether he had a three-phase supply, i.e. 400V between phases.

Why on earth would it be relevant what the precise meter reading is (and notwithstanding the fact that a meter reading has an inherent inaccuracy anyway)?