3 Phase Supply

[PickupSticks]

Before I start I am not an electrician and will be getting a qualified electrician in to carry out any work!

We lease a small office building in which is housed a number of computers. We currently have a three phase supply which
is on a sub meter from our landlords supply... Our supply is fused from the landlords main supply at 60A per Phase.

Our current load is around 40A per phase, about 15A of this is A/C load and a small amount lighting etc the rest is computers sitting behind a UPS which balances the load across all three phases.

We have the infrastructure and panel boards already in place capable of handling upto 400A..

We expect our load to grow to approximately 275kva within the next ten years..

I have a quote from Western Power for upgrading to a 275kva supply at £43,500... This is out of our budget at the moment and so we are looking at taking a smaller supply and then getting this upgraded at a later date or just renting another premesis.


Questions:
1) If we take a supply over 110kva I understand we have to move to half hourly metering. Our load is pretty much constant throughout the day/year as the equipment is running all day/year. I am aware it depends what plan we are on but generally speaking will half hourly metering work out cheaper
or more expensive for us?
2) Can I confirm that if we went for a larger supply despite being on a half hourly meter there would be no CRC charges as we would be needing to draw ~ 600kw constant usage to get anywhere near the 6Mwh/year limit..?
3) Could I keep my exsisting supply from my landlord to run A/C & lighting etc and just connect the new supply directly to our UPS? I think there are issues with having two supplies two one building..?
4) Standing Charges - Can anyone give me an example of what I would be expected to pay for say a 110kva and 275kva supply? I've no idea what to expect though think these things are a bit of a joke if they are already charging you for their substation upgrades and cabling!!


I appreciate any insights/thoughts anyone has on this!

 

[plugsandsparks]

These are detailed questions about charging for supply. So cannot help as its for you to negotiate. The cost of upgrade does not sound unusual but why not put the computers in a rented datacentre if thats whats using the power.
Plenty of installs i have come across have multiple supplies into a building so dont let that put you off.
FWIW - that size of supply is out of proportion for a small office building so you may find it hard to move. Perhaps look for a warehouse that has been upgraded which has some office space in it, you never know.....
Hope this helps

 

[Engineer54]

I'm thinking, with that amount of load, that will be required by your company over the next 10 years, you will be far better off looking for one of the smaller premises on an industrial/commercial park. Far bigger DNO electrical supplies will be, or should be readily available, either already in situ or from the park's existing distribution network that will pass close-by every unit on the park.

 

[Knobhead]

For a supply of 375KVA the DNO will insist on a transformer being installed. I think the cutoff point is 250KVA (400A).

 

[mechelec]

275KVA is on the limit of being on a single fused leg from the substation, i make it about 399A the max fuse size being 400A. I doubt you would be lucky enough to find anywhere else with a spare ACB in the substation LV pillar not being used. As Tony says you will need a new sub. I wouldnt have thought that getting a smaller supply in now and upgrading later would be economical as it would mean replacing everything that has been installed.