DNO Supply Question

[dominicbatty]

Hi RichardBurns, the supply over to our pavilion was put in to handle up to 63 amps per phase as the requirement, 15 years ago for hockey pitch lighting was much lower than it is today so we definitely don't have enough capacity in the existing cable but thanks for the suggestion.

 

[dominicbatty]

Hi Engineer54, I have a full lighting design from Philips, and I know the power requirements for both designs, 350/500 lux and for the lamps that are required so I'm well on my way with regards to that side of things, this power side is a steep learning curve but I'm getting there slowly. The problem with this sort of thing is the power side of things might make it or break it depending on availability of power and the cost of any change on the DNO side.

 

[dominicbatty]

Could someone answer me this. I'd just like to point out I'm enquiring so I can understand this whole thing better, I am fully aware this will all have to be re-done by suitable electricians and such like but getting good advice in the very early stages of grant funded applications is quite difficult hence why I'm leaning on a potentially helpful sole on these forums at the current time. The total power requirements of our project would be 28 x 2119w lamps, where each lamp is connected to 2x power phases. This results in a total load of 59.33 KW to achieve 500 lux lighting levels. We also have an option for 350 lux lighting levels using 20 lamps of the same type giving a total load of 42.38 KW. What I would like to know is what current per phase is required to support this project and what would this also be in KVA. If I have not supplied enough information then please let me know.

 

[Engineer54]

As R, Burns has stated above LED light fitting may be an option, but in any case a reappraisal of the overall lighting design for your pitch should be conducted. Things change over a 15 year period, especially as the trend these days is more and more towards lamp efficiencies etc...

 

[dominicbatty]

Hi, sorry I should have been more clear, the lighting design is brand new and based on modern standards. I've investigated LED lighting but it's not a viable option which would have been great in power terms. We're talking about lighting a 100m x 50m space to 500 lux and from the people I have spoken to who do this for a living, LED is not quite there yet.

 

[dominicbatty]

Aha, so Scottish Power got back to me today we are on a 95mm waveform cable and this can be moved to 200 amp fuses by just changing the fuses. 246.77 + VAT, great result. The one thing it does state is our requirements, one of them being "Provide interconnecting cable of an approved type between the termination equipment and your main switch gear. The cable size shall not be less than 25sq mm copper and must not exceed two metres in length". Does 25mm square sound enough for 200 amps per phase?

 

[Darkwood]

Your getting confused here the 25mm is the minimum by regulation not the size they are suggesting, you are at a stage now where you really need to get a competent Electrician on board with experience in commercial and industrial circuit design, ensure that this is there field and you don't get a souped up domestic electrician out of his comfort zone, there are too many questions to ask and info you need to provide us, a simple missed bit of info can be vital to a correct install.

Comments regarding discrimination earlier between consumer and DNO are usually not an issue as long as your fuses are less than or equal to theirs... normally we fit type II fuses where the DNO will fit type III or IV.

As the incoming N on the DNO will be possibly combined with Earth you will need an Electrician to establish that any consumer cabling upgrade is correctly done regarding the Earthing system

The original question seems to have been answered by yourself through enquiry but TBH this was the only way it could have been done with liaising with DNO as you will have been allotted a set KVA for which you will have a standing charge, if your supply was upgraded yrs ago without the alloted KVA set it could be the case they could turn around and say the supply upgrade isn't available and a very high cost of a new sub-station may have been on the cards, if you were marked up for your alloted KVA when supply was upgraded then you have been paying over the odds for your standing charge but safe guarding your KVA reserve within the local network.. this seems to be the case or you have been lucky that your requirements were still available in the local network.

We could ask you question after question and still miss crucial info as we would need to see the physical set up. I can appreciate you questioning for groundwork but this will all be normally done by your contracted electrician so don't get too involved or misunderstood info or incorrect spec's you provide may be costly and we aint talking a few quid here... we could be talking the whole cost of the install down the drain... ive seen this happen before.

 

[driverman]

and what did you downsize it to ?
because to achieve fault discrimination with 200A bs88 fuses , youre going to be limited to around 130-140A as the maximum sized protective devices on the consumer side.
which makes it pointless getting a 200A supply in the first place.

To be honest, I left them in. Never had any problems.

 

[Engineer54]

Modern daylight robbery being practiced.... £250+ VAT to change out 3 cartridge service fuses. Now that's what you call a profit margin!! lol!!

 

[Knobhead]

Sounds reasonable to me

 

[Guest55]

Sounds reasonable to me

agreed.
to be honest , the replacing of fuses is neither here nor there.
what you are really paying for is authorisation / approval from the dno to increase your max available supply.

so to get 200A for under £300 is actually pretty miraculous lol.

 

[mechelec]

Sounds reasonable to me

Totally agree. It is not just a site visit to change fuses. A study on the network capacity will need to be undertaken before any increase in supply capacity can be agreed. A connection agreement will be required (depending on DNO) which takes time to generate. It may seem a lot of money to change 3 fuses but there is a considerable amount of time required before that is carried out.

 

[Engineer54]

I understand what you're saying, but the processing work within the company is being carried out on a day to day basis as a matter of course anyway. It's not going to cost the company a penny in any additional costs.


I don't think i've ever seen a reasonable costing to any work the DNO's quote for. It's just that we've all been brainwashed to expect extortionate figures!!

 

[Knobhead]

Sorry E54, we’re both “old school”

It has to be done therefore it will be done to my book.

To be honest costing a job hasn’t figured much in my life..
I want, I get!.
The joys of multinationals!

 

[Engineer54]

Sorry E54, we’re both “old school”

It has to be done therefore it will be done to my book.

To be honest costing a job hasn’t figured much in my life..
I want, I get!.
The joys of multinationals!

It's all down to what i have always called ''Creative Accounting'' with these large utility companies...
They make the fee's up as they go, and according to what they think they can get away with, depending on client/customer status they are quoting. ...lol!!