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

[kensington]

he measured across and just to be clear again the supply cable is a 3 phase one the main head is a 3 phase head the feeds are all live at 100amp each 400v but for some reason keep being told its a single phase even the quote states to disconnect a single phase to upgrade to a 3 phase supply EVEN I HAVE 3 PHASE HERE... the only single phase thing is the meter

 

[7029 dave]

But it got R Y B on the head, between phase's should get in excess of400v

 

[Pete999]

So I have just had it independently tested and its confirmed that it is a 3 phase supply and each wire is pulling 100amp
so don't trust the visit from a uk energy technician. I will be filling a complaint to ofgem and the energy minister Amber Rudd
Having a cable just moved is just £900 not the £2300 quoted to lay a new cable when its already there

How on earth can each wire be pulling 100 Amps when there is only one fuse in use

 

[Guest77]

Hello all I have just purchased a 1970 Bungalow which is directly behind the main area sub station owned by Uk Energy Networks. My property has a 3phase head old brown bakerlite one I called up Uk energy networks who confirm that the property is indeed serviced by a 3 phase supply. I want the head cable moved from the kitchen into the garage about less than ten meters away and I also want 3 phase supply so finding out that the property had a 3 phase supply was a bonus .... however when the Uk Energy technician came and visited the property last week he did not test the head but remakes that its not necessary a 3 phase supply and that it was normal in the 70s to install a 3 phase head really??? he got out out the iPad and said the supply cable is bunched ???? and that a new 40 meter cable and I have to dig the trench would cost 3k.. my electrician has confirmed that all 4 fuses which say 100amp each are all live and 400v are on the head.. Are Uk energy trying to pull a fast one or can someone explain the bunched to me

regards
Mike
I have attached the pic of the mains head

Looks like a 3 phase cut out but only single phase in supply, the neutral is connected to the yellow phase end rather than the other end which is marked black, this tells me the cut out was altered to single phase some time ago, probably when a new meter was fitted.

 

[HappyHippyDad]

How on earth can each wire be pulling 100 Amps when there is only one fuse in use

I was wondering that pete. I'm thinking the cutouts have been removed and it has been seen that a 100A fuse is in each of them and that perhaps it is just the language that kensington is getting a little confused with. I have no experience with 3 phase but if each phase is testing at 400V (although again this value does seem unlikely, you would expect it to be a little more) does this not mean it is a 3 phase supply?

 

[Lucien Nunes]

This sounds like a storm in a teacup. YOU don't have a 3 phase supply because YOU don't own the head, the DNO does. It's up to the them what they can supply you with, as Darkwood says even if all three phases are present there might be other single-phase consumers using all the available capacity on the ones you aren't.

Your description of the test 'The sparky tested all cables at the head each measuring 100 amp each' does not make sense electrically, so you might have confused the results. In any case that test involves tampering with equipment that is not yours and is possibly an offence to gain access inside.

If your supply is taken from an older network, there are various possibilities as to why what might first appear as a 3-phase service cable is actually not. Hence, possibly, the mismatch between your neutral connection and the phase markers.

 

[Risteard]

How on earth can each wire be pulling 100 Amps when there is only one fuse in use

Exactly what I was asking earlier!

 

[Risteard]

testing at 400V (although again this value does seem unlikely, you would expect it to be a little more)

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.

 

[Darkwood]

he measured across and just to be clear again the supply cable is a 3 phase one the main head is a 3 phase head the feeds are all live at 100amp each 400v but for some reason keep being told its a single phase even the quote states to disconnect a single phase to upgrade to a 3 phase supply EVEN I HAVE 3 PHASE HERE... the only single phase thing is the meter

The link Snowhead kindly provided explains what a bunched cable is, it clearly states that it has to be replaced because it is a bunched cable, basically the spare cores have been used to double up the cores in use to possible reduce the overall resistance.
Quoted from the link:-

Any alterations to networks including bunched conductor installations shall make provision for the restoration of a conventional network solution.

Their own regulation means it has to be replaced

I too don't understand what you say your electrician is confirming, like has been said it is very confusing from an electrical point of view, your pic shows the cutout is sealed so he has no way of testing with meters what you have in there, regardless of it been a 3ph head, I don't think you are in anyway been over charged or having work done that isn't neccessary and going at them with little subject knowledge is only going to create waves and cause you delays and problems, that's if they don't just turn around and say forget it then.

 

[snowhead]

A potential cost saving idea might be to ask your energy supplier, not UKPN for a 3 phase meter, which you'll have to have anyway and Customer side 3 phase isolator.

Before they install it they'll have to confirm with UKPN that the supply is 3 phase and can be used.

Once the meter is in, assuming it can be, apply to UKPN to have the supply relocated.

 

[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.