Please help DNOs KVA……??

[Heyyall]

Hi all,

I’m getting confused as to what the DNO are going to be installing as there main supply and as you all may be aware they tend to be a little shy at replying back.

We have been told ukpn will be supplying us a maximum of 270kva to a block of 24 apartments.

I am assuming this will be 270 kva three phase, being 200 amps per phase (I can’t imagine it being 400 amps per phase)?
Could anyone confirm this in their past experiences?

I’m querying this as I need to know sizes for tails and isolators before they come to connect the main head.

Any help/advice be appreciated.

 

[pc1966]

270kVA = 1174A single phase 230V = 392A 3-pase 400/230V. Basically 400A

I fear you are bit out of your depth here.

 

[plugsandsparks]

kVA to amps (A) conversion calculator

Kilovolt-amps (kVA) to amps (A) conversion calculator and how to calculate.

www.rapidtables.com

Give that a go... think 400A is what they are proposing, hopefully the head has got smaller as its a bit of a beast, lol

 

[Heyyall]

kVA to amps (A) conversion calculator

Kilovolt-amps (kVA) to amps (A) conversion calculator and how to calculate.

www.rapidtables.com

Give that a go... think 400A is what they are proposing, hopefully the head has got smaller as its a bit of a beast, lol

Thanks for reply. Would you happen to know roughly dimensions of the head. I’m hoping 600mm x 850mm (width x height) will be enough space.

 

[davesparks]

Thanks for reply. Would you happen to know roughly dimensions of the head. I’m hoping 600mm x 850mm (width x height) will be enough space.

UKPN will have supplied you with this information, if not then you can ask for it, along with their requirements prior to connecting.

It's not just the size of the cutout itself but also the working space around it that is required.

Also note that you have been given the maximum possible KVA of the supply, what you actually get may be less than that and will possibly be what was asked for on the application.

 

[Rockingit]

As others have said - without sounding unkind, are you confident in your abilities with this project?

 

[davesparks]

If you register for access to the UKPN document library online you can view a lot of their design standards and drawings for standard new supplies.

For this question you may want to have a look at
EDS 08-1103 supllies to multiple occupancy buildings
EDS 08-2100 LV customer supplies (covers supplies from standard single phase up to 1500KVA)

EDS 08-2110-08, EDS 08-2110-10, EDS 08-2110-11, EDS 08-2110-19 are drawing of various different cutout arrangements that may apply to this particular supply.

 

[Heyyall]

As others have said - without sounding unkind, are you confident in your abilities with this project?

I’m just asking for a bit of advice mate. As I have said……DNO not handing information over. Exactly why I’m on this site asking.

 

[Heyyall]

If you register for access to the UKPN document library online you can view a lot of their design standards and drawings for standard new supplies.

For this question you may want to have a look at
EDS 08-1103 supllies to multiple occupancy buildings
EDS 08-2100 LV customer supplies (covers supplies from standard single phase up to 1500KVA)

EDS 08-2110-08, EDS 08-2110-10, EDS 08-2110-11, EDS 08-2110-19 are drawing of various different cutout arrangements that may apply to this particular supply.

That’s great advise. Thanks a lot.

 

[James]

Bear in mind that tails for 400A are difficult to manage, even as singles, 240mm rings a bell but would have to check with the dno.
make sure there is plenty of space for the cable bends as they will be quite large, 300mm rad would not be unusual.

 

[plugsandsparks]

Thanks for reply. Would you happen to know roughly dimensions of the head. I’m hoping 600mm x 850mm (width x height) will be enough space.

As mentioned, you really have to beat up DNO to provide their spec, you cannot be expected to guess what they are going to rock up with. The question in my mind is how is this all going to be distributed to 24 supplies, busbar chamber ?? - Where is the demarcation point for you in this scenario. I dont do flats just comm and industrial but somehow the 400A incomer has to turn into many smaller supplies and this takes up alot of space, probably a whole room with meters and the like. Hopefully someone on here can fill in how the single supply gets cut up for flats.

 

[Julie.]

Bear in mind that tails for 400A are difficult to manage, even as singles, 240mm rings a bell but would have to check with the dno.
make sure there is plenty of space for the cable bends as they will be quite large, 300mm rad would not be unusual.

DNO standard for 260-300kVA will be 300mm^2

240mm^2 would cover 230-260kVA

 

[James]

Is that for the supply cable Or the meter tails?

 

[Julie.]

Hi all,

I’m getting confused as to what the DNO are going to be installing as there main supply and as you all may be aware they tend to be a little shy at replying back.

We have been told ukpn will be supplying us a maximum of 270kva to a block of 24 apartments.

I am assuming this will be 270 kva three phase, being 200 amps per phase (I can’t imagine it being 400 amps per phase)?
Could anyone confirm this in their past experiences?

I’m querying this as I need to know sizes for tails and isolators before they come to connect the main head.

Any help/advice be appreciated.

In my experience there is never any difficulty in obtaining the information from DNOs for this sort of thing, as has be already stated each DNO makes their generic information freely available.

I attach ENWL's versions of a couple of documents that would be appropriate in an installation of this nature as examples. Noting that all DNO's have their own version, which are usually virtually identical across all DNOs.

The only caveat is that DNOs will follow the contract path rigidly!

The connection agreement will be between the DNO and the customer - information will be freely available across this route, and if the customer tells the DNO, "Heyyall will be acting as our technical representative in this matter " then exact information would be directed through you. This would include all specific drawings and the like for this particular installation.

They will not divulge this information to a random third party, even if you are intimately involved with the project, from the DNO's perspective, you are a random third party.

 

[Julie.]

Is that for the supply cable Or the meter tails?

Meter tails.

 

[Heyyall]

In my experience there is never any difficulty in obtaining the information from DNOs for this sort of thing, as has be already stated each DNO makes their generic information freely available.

I attach ENWL's versions of a couple of documents that would be appropriate in an installation of this nature as examples. Noting that all DNO's have their own version, which are usually virtually identical across all DNOs.

The only caveat is that DNOs will follow the contract path rigidly!

The connection agreement will be between the DNO and the customer - information will be freely available across this route, and if the customer tells the DNO, "Heyyall will be acting as our technical representative in this matter " then exact information would be directed through you. This would include all specific drawings and the like for this particular installation.

They will not divulge this information to a random third party, even if you are intimately involved with the project, from the DNO's perspective, you are a random third party.

This is great stuff thanks. The problem I have is that the developer has used a consultant from another company to deal with the DNO and therefore I am left out of the picture. Asking the Developers for info is like getting blood from a stone. But with this I’ll see if I can obtain direct contact with them passing my details on.

 

[suffolkspark]

DNO standard for 260-300kVA will be 300mm^2

240mm^2 would cover 230-260kVA

I've just had a 200kva supply put on to a new job, 315A fuses, they asked for 150mm tails, in trunking, chart they gave me is attached. Standard 70°c 6181y aswell.

 

[Julie.]

This is great stuff thanks. The problem I have is that the developer has used a consultant from another company to deal with the DNO and therefore I am left out of the picture. Asking the Developers for info is like getting blood from a stone. But with this I’ll see if I can obtain direct contact with them passing my details on.

That's really my point about third party.

From the DNO's perspective, and contract obligations not only are they not willing to give you this information; they will be contractually obliged to not divulge it.

They have most likely already provided it to the relevant party.

If this needs to be disseminated though to others, it is the responsibility of the developer.

 

[pc1966]

I dont do flats just comm and industrial but somehow the 400A incomer has to turn into many smaller supplies and this takes up a lot of space, probably a whole room with meters and the like. Hopefully someone on here can fill in how the single supply gets cut up for flats.

From what I have seen it is usually a Ryefield board after the main isolator and any CT-based meter for the whole supply, but as you say it depends on where the meters are (if they are all per-flat so just some SWA or concentric to each flat with a red link in the cut-out, or if the switch-room has all meters in one place, etc.)

Hopefully there is a plan!

 

[Julie.]

I've just had a 200kva supply put on to a new job, 315A fuses, they asked for 150mm tails, in trunking, chart they gave me is attached. Standard 70°c 6181y aswell.

It looks like they have split it up differently to most DNO.

That supply was for a multi-occupancy building wasn't it?