3 phase Meter Arrangement

[DjSparkos]

Hi, I have been asked to 'get the installation ready' for the electricity supplier to come and fit seperate meters.

Currently:-

The building is broken up into 5 seperate dwellings

There is a 3 phase supply running straight up through a Ryefield dist board. The 3 phase and N Supply cable has been made off and terminates straight into an old style meter. 3 phases and N have then been taken back off the meter and into the ryefield board to supply the seperate portions of it.

One phase (red) supplies 2 dwellings via 2 x 100A main fuses, blue phase supplies another 2 dwellings via 2 x 100A main fuses and the final phase supplies the last dwelling via 100A main fuse and a seperate dist board for the communal areas (no RCD for communal areas). 5 seperate 3 core SWA cables then feed off the appropriate main fuse to a consumer unit within each dwelling.

The client doesnt want the electricity usage for all dwellings to be read off of this one meter. Hence why she has arranged for the supplier to fit 5 seperate meters.

As the 3 phase supply feeds straight up and into the single meter for the property, I am unsure if i can even isloate the supply, unless I missed a seperate meter cupboard which houses another main fuse.

Would I be right in saying that if the 3 phase supply can be safely isolated, it would be acceptable to completely remove the current meter. Re - Gland the 3 phase supply cable at the bottom of the current Ryefield dist board, then re-supply the ryefield board appropriately from this supply cable...from the seperate main fuses currently being used for each individual dwelling could I then supply the new seperate meters for each dwelling (with N too obviously). The 5 SWA supplies to each flat would then also seperately terminate into the 5 new meters?

I have limited experience on 3 phase as the vast majority of supplies I work on are single phase. Is this a whole job for the electricity supplier? I'm sure someone on here has the relevant experience to give me some wisdom. Apologies for long winded explanation.

If your in my local area and have the right experience for this I may even sub the work out and attend with you. Any advice will be appreciated!

 

[DjSparkos]

I mean...considering its the electricity suppliers cable Im assuming I cant even go near it......It's just a set up I havent come accross before.. 3 phases straight into the meter :s..... Unless I have missed a seperate dist cupboard....landlord wasnt even on site so I was shown locations of things by the CCTV contractor

 

[malcolmsanford]

There is not really a great deal you can do yourself here.

If I understand you correctly the 3 phase header coming into the building feeds a 3 phase meter which in turns feeds a Ryefield 3p+N+E DB and from there singled phased supplies go to each flat, so in essence all 5 dwellings + the communial areas are metered off the 3 phase meter.

Legally you can not touch either the header or the meter. Though in practice many sparks do remove the supply fuse to isolate the installation, it is not legal, and touching the meter is an even graver offence.

Unfortunately the majority of this work will have to be done by the DNO and the meter supplier company which now a days is often 2 completely seperate companies. So your DNO could be Scottish Power and your electricity supplier for the meter be British Gas as an example.

The DNO will most likely not do a lot of work their head is already in situation and they would come and isolate basically. The meter company would remove that 3 phase meter, but what happens next is down to discussion.

There must in situ be a set of 3 phase tails from the load side of the fused DNO header to that 3 phase meter, the one you are thinknig of re-glanding but don't unless you get the DNO permission to do this. The DNO will assess if these tails are sufficient and in all probaility will change them. They may after your discussion let you change them to keep down costs, but that is something you need to discuss with them.

Once the tails have been sorted, they will run to the Ryefield board. Again this my have to be changed, and again it will be DNO who will decide this, they may feel it is too old or inadequate, but again it is just something you will need to sort out with them.

Once this part is done you can run your single phase supplies and leave them ready for the meter company. They will come in and fit and hopefully all will be well.

I can't help thinking that perhaps there maybe an alternative here. Only your customer can decide this. All this work involving DNO/Suppliers is not going to be cheap. Could another scheme be to keep the installation as is before the Ryefield board and just fit a private set of meteres for each dwelling, which your customer will bill the flat occupants for. Obviously if they are tenants this is straight forward, but if the customer is going to sell the dwellings off, then obviously you need to do the work.

 

[Knobhead]

As Malcolm has said if they are rental properties then you could fit 6 separate meters, don’t forget you need one for the communal areas. If you don’t intend to replace the feeds the each dwelling they can be through crimped and sleeved to extend them to the individual meters. You will probably have to hire the correct crimping tool for the size. Or if you’re good with a gas torch and free flow soldering you could do it the old fashioned way. (It’s the way I’d do it, but then I’m old fashioned)

Don’t forget if you extend the tails to separate meters you must take each pair of tails out of the same hole if in a metal (steel) enclosure to stop eddy currents.

If the properties are for sale then it’s down to the supply companies to sort it out.

 

[DjSparkos]

Thanks for the very helpful advice.

I think your suggestion of leaving the supply as is, is viable as all dwelllings are rented and not going to be sold. Fitting 6 private meters is a going to be the best way, so thanks for that suggestion. On the SWA feeding each dwelling there is alot of slack on the tails, re-routing those into the new meter positions won't be a problem. I can then supply each individual meter via a new set of meter tails from within the Ryefield

The current Ryefield board is a steel enclosure. To avoid Eddy currents what level of segregation will be needed? When you mention 'each pair of tails', I take it you meen the Phase and Neutral feed for each new meter?

If the job is done like this and seperately metered, the landlady will still get billed for the property as a whole through the readings of the 3 phase meter. Will she then have to take readings off of the seperate 5 meters herself to determine who owes what amount, in terms of electric usage?

Thanks again for your help, if you get any further time to answer, I'd appreciate it.

p.s - I think I'll leave out the soldering!

 

[malcolmsanford]

The phase tails going into the Ryefield if they are single cables ie 3 LINES 1 NEUTRAL and 1 CPC then as Tony suggests they should all enter a metal enclosure through a single hole entry, if you say put 2 LINES 1+1 LINE/NEUTRAL and 1 CPC through 3 individual holes then you would create eddy current circulating around the enclosure. What you do if that was the case is cut between the holes with an hacksaw in essence spliting the enclosure. If of course your going to SWA it as it seems it is now then there is no need to worry to much about that, but you will need to earth the SWA to the enclosure with a banjo

I must admit every landlord I every dealt with prefered the private meter route, as they can really place a mark up on the energy used. If the flats were metered by the supplier then the bill goes to them, whereas if it went to the Landlord, she would just read the private meter and perhaps add a 10% charge. You could even fit her key meters which again would be set up by her, and costed at her rate which most likely be above the supplier tariff, that way she will not need to read anything.

 

[Des 56]

Yes I agree,private metering if at all possible

A mark up on the overall bill will give a profit incentive for them for firstly having to record + administer each account seperately, and as a contribution to the communal standard charge, and as a standard charge for maintenance and purchase of the meters

 

[Knobhead]

p.s - I think I'll leave out the soldering!

Coward!

 

[Knobhead]

If the job is done like this and seperately metered, the landlady will still get billed for the property as a whole through the readings of the 3 phase meter. Will she then have to take readings off of the seperate 5 meters herself to determine who owes what amount, in terms of electric usage?

Yes the landlady will get one utility bill. It’s then up to her to calculate the proportion of the bill to each flat. It’s dead simple using Excel, I did a spreadsheet for a landlord last year but I can’t find it at the moment. If you ask I’ll knock one together for you.

Or as Malcolm suggests Key meters, but depending on the quality of the flats that may not go down well with the tenants.

 

[DjSparkos]

Thanks for taking the time Gents, I appreciate it alot.

Tony I'd be very interested in seeing your speadsheet if you get the time mate.

The land lady is very busy (arent we all) and the less she has to do the better in regards of meter readings and the like. If I were to fit 5 key meters and one standard meter (for communal area), I take it the tenants would retain the keys and put electricity onto thier meters at thier convenience. How would they put more electric onto thier keys though? I know on a typical key meter, the tenant would pay for the electric at a relevant shop, would this still be the case?

I know I'm takin the mick with amount of questions so sorry for that. My query is more in regards of the payment set up as opposed to electrical set up. Appreciate any input.

Cheers, Rob

 

[Engineer54]

Correct me if i'm wrong here, ...but as far as i'm aware it is strictly forbidden to re-sell DNOs metered power, making a profit, and comes with some real hefty penalties and fines for those that fall foul....

 

[Des 56]

Correct me if i'm wrong here, ...but as far as i'm aware it is strictly forbidden to re-sell DNOs metered power, making a profit, and comes with some real hefty penalties and fines for those that fall foul....

<br><br>

You seem to be well on the right track.but a paragraph from this link suggests commercial and industrial is exempt
http://www.ofgem.gov.uk/Consumers/Documents1/11782-resaleupdateoct05.pdf


And I seem to be well on the wrong track because the installation consists of dwellings,so another read is needed by me

 

[Engineer54]

I think in this case, (ie, ...the subject of this threads situation) you can safely say this is a Domestic arrangement, and therefore subject to that maximum re-sale price...

I haven't read anywhere near thru this document, but i think there will be something in there about VAT rates/charges too...

 

[DjSparkos]

Well thanks for your input. The real purpose is for the Landlady to be able to monitor each individual tenants electricity usage. The property is in Maida Vale so I doubt she is too concerned about making a few quid on top of the bills anyway.

My query is regarding the practical application of the key meters for both tenants and landlady. Any input appreciated.

 

[rallyandy]

with the property being in Maida Vale , key meters might be a bad option if she is going for private tenants, unless she intends to take council tenants mainly because not many shops are set up for private payment cards. I installed private card meters in some flats for someone he buys the cards with preset values on them ie 5 10 20, which is not a problem as he sells them from his shop. if you landlady chooses this route she would have to make these cards available for the tenants

Im also pretty sure you cant by Key meters privately the are for energy suppliers only