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Discuss What KVA value - Can someone help please for a tyre garage, MOT station and offices in the Commercial Electrical Talk area at ElectriciansForums.net

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Hello all

I am new to this site and i am glad i have found it as it looks crammed with useful advice from people in the know.

I am not too familiar with how forums and posts work and i hope i have not made a mistake by uploading this, so please excuse my ignorance in advance if i have offended or inconvenienced anyone.

I just need a bit of help please and guidance if possible about the KVa value that we need to give to the local DNO who manage the electricity network in the area. We have taken over an old factory which is on a site which had its own HV substation but we have no contact with the owners of that part of the site so we need our own new LV electricity connection from the road which will enable us to have our own MPAN number and billing etc.

The DNO say that the transformer on that road has a capacity of 500kva of which 461kva is being used already and so they say they can only offer 49kva (but 500-461=39kva so i do not understand where they got 49kva from!) They say that if we want more power then we have to pay to upgrading the transformer which at the moment i feel is bullying us as they have the monopoly and other people will benefit also. They are very slow and do not respond swiftly to our emails. I am surprised at their lack of professionalism seeing they are in a very responsible position.

The building we are moving to is an old 3 storey factory and we are using it for mainly storage of tyres, some car servicing, tyre changing, MOT testing and possibly splitting the top floor into 25-30 small offices to sublet. The bottom 2 floors will mainly be for storage of tyres. I have got some values about the size of each floors and power ratings for the equipment that we will be using:

2x car ramps @ 3kw each, 3 phase
1x air compressor @ 3kw, single phase
tyre changer @ 0.75, single phase
tyre balancer @ 0.75, single phase
Car tyre tracking machine - same consumption as a PC

Various other uses of power:

Whole building:
Security Cameras/alarm and Fire Alarm and 2 security lights which are motion activated, outdoor sign, on at appropriate times

Ground floor about 10,000 square foot - for tyre changing, service, MOT,tracking:
Tyre and MOT equipment (listed above with the Watts values)
Lift (out of order at present - SLIM chance that we will use it at a later date)
3 phones
3-4 computers with internet
Lighting for office and waiting area size about 15m x 8m
Lighting for ground floor storage along the middle - 50 metres long x 11 metres wide - not on all the time so can have sections coming on as we work in an area

Middle floor about 10,000 square foot - 65 metres long x 11 metres wide - storage area
Lighting along the middle for storage area - not on all the time so can have sections coming on at a time
Lighting for middle floor toilets - one toilet 4m x 3m and second toilet 7m x 5m - not on all the time

Top floor about 10,000 square foot - possibly split into 25-30 smaller offices to sub-let at later date
Lighting along middle along top coridoor - 65 metres long x 2 metres wide
Supply for 25-30 offices / storage rooms - each office is about 4.6m wide x 4.2m deep on average - not on all the time - they MAY use light, 1/2 computers, phone, fax, internet, radio, electric heater, phone charger, etc if it is being used as an office or just the light if it is used for storage
Lighting for top floor toilets - one toilet 4m x 3m and second toilet 7m x 5m - not on all the time

Please note, central heating may be activated at a later date for the whole building, especially the ground floor office / reception area and the top floor at a later date if the renting of offices goes ahead. Before that we may have to settle on electric heaters for the waiting area and office so that may need to be considered in the kva calculation. Electric heaters may be used in each office that we rent out so that could add to what we need also (imagine 25-30 offices all using their own electric heaters!)

The electricity company have said that their current quote for the connection is for 49KVa and is available and if we need more then the cost will be more. They say we can't have a low power cable now and just upgrade later, they treat it like a new connection so we will be paying double later.

I appreciate your time in reading this and i look forward to ideas and thoughts from anyone about what KVA we should ask for.


TyreCo Birmingham


Electrician's Arms
Re: What KVA value - Can someone help please for a tyre garage, MOT station and offic

You really need someone to come and assess your demand accurately. You will certainly need more than the DNO is offering at present. You should not have to pay the full cost of a new tx as you will not be the sole user. Apportionment should be applied so I would find out the exact demand you are likely to need in the future and get a quotation from the DNO
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