PME Supply Advice

[bilbo_88]

Afternoon All,

Just pricing up a job and thought I'd pick your brains.

Quick run-down, Block of Flats with an underground car park. In the mains room each individual flat has a supply ran up to the flat (picture for reference) with a split concentric. The PME connection is provided within the flat via a connection at a Solid Link Fuse (typical house service fuse block) via the N.

So I need to install a sub mains next to the fuse in the mains cupboard (downstairs) supplying a socket for a hybrid car within the underground car park. My question is can I supply the submains with a TNCS supply via the Henley Block or a link within the Consumer Unit itself, or will I have to contact the DNO directly to provide me with a connection? Not something I have had to deal with before. I have noticed that other contractors have done the same but was unsure if it is the correct way to do it.

Thanks!

 

[buzzlightyear]

Just put in a second CU for the car charger.
There is a Henley blocks at the cut out.
Looking at you pics.

 

[loz2754]

Just put in a second CU for the car charger.
There is a Henley blocks at the cut out.
Looking at you pics.

Yes but the problem is there is no connection to earth available at the intake.

 

[bilbo_88]

Just put in a second CU for the car charger.
There is a Henley blocks at the cut out.
Looking at you pics.

Yes that is my intention, however no connection is available for the earth

 

[buzzlightyear]

What cu are you going to put in that's the case.
Where is the Ads.

 

[buzzlightyear]

Yes but the problem is there is no connection to earth available at the intake.

Correct, there must be earth's on the ground floor, I hate when Peaple only show half a pic, how is this to be done.

 

[bilbo_88]

What cu are you going to put in that's the case.
Where is the Ads.

2 Way Consumer Unit w/ Main sw & RCBO

 

[buzzlightyear]

Op

2 Way Consumer Unit w/ Main sw & RCBO

Double pole, me thinks.

 

[loz2754]

It does seem unusual to not have an earth terminal at the intake to the building. How is the main bonding done?

 

[bilbo_88]

It does seem unusual to not have an earth terminal at the intake to the building. How is the main bonding done?

There is an Earth Bar in another mains room, approx. 20m away next to the Ryefield Board that supplies each of these meters

 

[buzzlightyear]

There is an Earth Bar in another mains room, approx. 20m away next to the Ryefield Board that supplies each of these meters

There is a small cu in that pic you sent
So the cpc must go in that back to the earth bar.

 

[bilbo_88]

There is a small cu in that pic you sent
So the cpc must go in that back to the earth bar.

No, the only cables entering this are L+N from the henley. I can only assume they have linked internally within the CU

 

[buzzlightyear]

No, the only cables entering this are L+N from the henley. I can only assume they have linked internally within the CU

The Ryefield Board is in another room yes, there is a small cu next to the cut out.
Put a diagram on here so that we can work it out.

 

[bilbo_88]

The Ryefield Board is in another room yes, there is a small cu next to the cut out.
Put a diagram on here so that we can work it out.

Please forgive my crude attempt lol
That small CU next on the adjacent fuse must have linked N+E within the CU as there are only the L+N tails entering and SWA leaving

 

[buzzlightyear]

Please forgive my crude attempt lol
That small CU next on the adjacent fuse must have linked N+E within the CU as there are only the L+N tails entering and SWA leaving

Bloody hell did a kid do that drawing or are you drunk. Lol
CU in, earth's back to the Ads. That probably needs doing.
That's going to cost some pennys.

 

[bilbo_88]

Bloody hell did a kid do that drawing or are you drunk. Lol
CU in, earth's back to the Ads. That probably needs doing.
That's going to cost some pennys.

Both lol

Thanks for the advice, client will be chuffed lol

 

[buzzlightyear]

Thanks for the advice, client will be chuffed lol

What with the drunk drawing or drunk kid
Doing it.

 

[bilbo_88]

What with the drunk drawing or drunk kid
Doing it.

Just reading some regs and need to make sure I am not misinterpreting it. If a ran an earth back to the earth bar by the Ryefield board, would I not be contradicting 543.4.3? And in that case would I link CPC to Neutral at the Henley block in the mains room (as it seems other have done) as to not contradict it?

 

[mhar]

You do not link the E to the N, we are not allowed to do that.
Whole thing sounds unusual, first port of call should be a call to the dno with an earthing enquiry. In my area they are extremely helpful

 

[davesparks]

Lots of confusion here it seems.

That looks to me like a block of flats which had it's electricity supplies installed by a regional electricity board in the days when they existed and before anyone realised that distributing PME internally in a building is a very bad idea.

These days the individual services to each flat would be TNS with only the incoming main possibly being TNCS.

So what you have there is a concentric/CNE (combined neutral and earth) cable coming in to the cutout, then the meter and outgoing from that another CNE cable coming out of there and presumably going to a redhead isolation link in the flat.

In this arrangement the consumers supply terminals are at the outgoing side of the redhead isolation link and not at the meter as they would normally be.

So the consumers installation begins and the flat and everything before that is the property of the DNO, except the DNOs have washed their hands of internal wiring a n blocks of flats and it magically became the property/problem of the BNO (which may not even exist for the building)