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This is way OTT for what you would need, smaller 3Ph pole mounts are available. You have to ask UKPN for the upgrade cost, be prepared for a nasty shock.
 Are you saying you think 100A TP is OTT? What do you think would suit me then in your opinion?

 
Personally, I would have two separate supplies, keeps HMRC out of the equation, and does not taint your personal affairs with those of the business.

Engineering wise, you cold run the house off the 3ph along with the yard, but, due to the distances involved you are no better off are you.
you're right it doesn't give me much gain. I would have a 100A supply to the house instead of a 80A but it would depend on the costs of paying two supplies vs just one. As for hmrc it can be calculated during the accounts so I wouldn't expect much problem there. If I save £150 a year or whatever in fees for 50 years its worth thinking about cutting back to one cable.

 
Sorry tony s the picture hadn't loaded when I read your comment I understand now. Any ballpark estimate as to cost of a small 3ph pole mount transformer?

 
 Are you saying you think 100A TP is OTT? What do you think would suit me then in your opinion?


The transformer in the picture is OTT

Sorry tony s the picture hadn't loaded when I read your comment I understand now. Any ballpark estimate as to cost of a small 3ph pole mount transformer?


Replacement of the Sp Tx for a new 3Ph Tx along with the cable, metering, etc will cost an arm and a leg. A split phase supply will be about the same.

You really need to rethink your plans and assess the value to your business along with the disruption the conversion will cause.

If you’re planning on expanding with things like boat lifts and such then 3Ph will be an advantage.

Only you can decide on the value to your business.

Your best bet is to phone UKPN and ask.

Just sit down when they tell you the price.

 
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There is a sailing club near me (not the one I am a member of) who for years have just used a generator. They have just for the first time had their own mains supply which involved extending the overhead line about half a mile, new pole mounted transformer, and LV cable under the road into the club house.  I will see if I can find out how much it cost them.
 

 
you're right it doesn't give me much gain. I would have a 100A supply to the house instead of a 80A but it would depend on the costs of paying two supplies vs just one. As for hmrc it can be calculated during the accounts so I wouldn't expect much problem there. If I save £150 a year or whatever in fees for 50 years its worth thinking about cutting back to one cable.


The issue with HMRC is that if your personal accounts and affairs are tainted by the business, then you can be personally investigated along with the business, if they are seperate then HMRC cannot investigate you personally.

One other thing to think about, 3ph equipment tends to be cheaper than 1ph.

Last thought for now, 3ph wiring for the same power requirement for an equivalent powered load, is smaller than 1ph.

 
There is a sailing club near me (not the one I am a member of) who for years have just used a generator. They have just for the first time had their own mains supply which involved extending the overhead line about half a mile, new pole mounted transformer, and LV cable under the road into the club house.  I will see if I can find out how much it cost them.
 
I'd be very interested to learn what that set them back thank you!

 
Your best bet is to phone UKPN and ask.

Just sit down when they tell you the price.
I'm working up the courage.. Also as I previously mentioned I've been told if you don't go with their first quote they batter you with a higher quote the second time round

 
I'm working up the courage.. Also as I previously mentioned I've been told if you don't go with their first quote they batter you with a higher quote the second time round




Who told you that?

The first price will be high, like a 2nd hand car salesman, they’ll negotiate to get the sale. You need someone with experience to negotiate for you.

 
Who told you that?

The first price will be high, like a 2nd hand car salesman, they’ll negotiate to get the sale. You need someone with experience to negotiate for you.
Has that been your experience with organising new supplies?

a mate who has just put in a TP 100A supply about 100m cost him £16k but he did need a couple of permissions and one to get across a railway. He was given that advice by somebody who works for the power company I think putting in new supplies. Unfortunately I can't track him down.

 
Ok I may be wrong about having to go to uk power networks... Could I use an ICP? an independant connection provider? If so I could contact various companies to discuss and get various quotes to bring the price down before contacting uk power networks for their quote

 
You can use an ICP, but, they can only do the contestable works anyway, which UKPN will list as separates in their quote AFAIK.

Are you sure that UKPN are your DNO, as you don't list where in the UK you are, and UKPN are not the nation wide DNO.

 
Canoeboy said:
I find the first quote from the office is very expensive and then if you get an engineer out to look and re-quote you get a sensible price from someone who knows rather than a pen pusher who looks it up
That's heartening news. I really do need a site visit from an engineer. How do you go about getting one? Do you just write on the form that you would like one?

Yes I'm in essex so uk power networks for this area

 
Ok, now then, you can speculate and plot and scheme all you like, you will get precisely nowhere and are doing things completely backwards...

1, UP TO A POINT, it is not what size supply you want, it is what size supply they are prepared to give you, as "network capacity" COULD be an issue.

2, Now, let's pretend that you COULD just say I want a such and such size supply. If it is within network capacity great! If not, and they have to "reinforce" the network, what it costs all depends.. They proportion the cost out. Say they had to install a new substation, or ten miles of new cable. IF you were the only person to benefit, then you would pay the whole cost. BUT, say the new transformer and ten miles of cable would be also used to supply the new estate of 1000 houses that are building up the road, then you would only pay 1/1000 of the cost.

3, For what you are doing, unless you want to use "DIY" toy welders etc, you need a proper three phase supply. Also, they WILL NOT give you a single phase supply bigger than about 80 or 100A end of.

4, You do not tell them what size supply you want, THEY TELL YOU what size you need and they are prepared to supply...

5. They all have a standard form that they want you to fill in. They will want to have details of ALL equipment you want to connect. They will especially want details of all motors, kW/hp, phases, DOL or star/delta, number of starts and stops per hour, how long will the thing be running for, between what hours.

Same for welders. Size, voltage, phases, welds per hour. They hate welders!!

They will also want you to give the rating of all of the above in kVA. It follows from this that you need a PROPER electrician to fill in the forms for you. HOWEVER, in your case, it might be best to just write down all the information in a letter, and explain that you are a one man business, and that only one machine will be used at any one time etc, or they will assume you have a full scale machine shop.

6, FORGET telephoning them, they will simply tell you to fill in a form. They will also NOT give you ANY advice at all, apart from; "you need an electrical engineer to work out what your demand will be" [both before [total connected load] and after diversity]

7, PLEASE do not let all the above put you off!!!! It is not half as bad as it sounds, they WANT you to have the supply after all!!

8, Do not listen to muppets in pubs as to what it costs. In most cases, FAR FAR less than you would expect.

9, Anyone that thinks that if they give you a price and you turn it down. next time it will be more is also a muppet. I know someone that wanted a supply and they were quoted £3000. When they said they they could not afford that, the DNO said; "Oh, ok, £2000 then!!!!!"

10, Biggest problem you got, is that it looks like you will need a new transformer up the pole. They are rather expensive.....

11, Did you know that the DNO have to publish a price list??? It might not mean much to you to be honest, but the others on here will be interested. They do worked examples too!! One is nine MILLION quid!!

Here is the link; http://www.ukpowernetworks.co.uk/internet/asset/9d530978-7a14-4251-89a2-21f7a50a55bJ/UKPN-Common-Connection-Charging-Methodology-Statement-October-2012[pdf].pdf

12, The first thing you have to do then, is to get a PROPER electrician to work out the information that I have given in 5 above, [together with details of any other loads] then fill in the form or write a letter. The planners will do their number crunching, someone will do a site visit, and then they will give you a price..

So far as I know, UKPN can either do you a rough estimate, OR, if you want an exact price, they can do that too, but you are committed to having the supply. You will have to take this up with them.

Only bad news is that according to their price list a pole mounted transformer change is £7500, but you never know, they might have an old one. It is entirely up to whoever deals with it, so be nice to them!!!!

john...

 
As i thought it might help, i have posted a copy of my actual application to the DNO when i did mine. I have done applications for other people too the same way as it explains things much better than their "official" form for situations such as "one man" businesses.

As you can see there is quite a lot they need to know. i sent in my letter and a few days later went to see them to se if it was ok. I was told "Oh yes!! the planners say they have everything they could have wanted"

Total cost for mine with the 25 metre service cable, AND 25 metres of 4" duct, AND the meter box, was about £1500 INCLUDING the vat. I was well pleased!!!

Anyway, here is my actual application...

Dear Sir,

Please can you give me a quotation for a new three phase electricity supply to be connected to my workshop building situated to the rear of my property located at the above address.

I have supplied a plan of the site [Attached] and I have also tried to give you as much other information as I possibly can to assist you with this.

As can be seen from the attached plan, the service cable length from the proposed meter position to the boundary of my property with the pavement is just under 25 metres.

The service cable would be run underground, and I will dig the trench on my property myself, to the required depth, complete with stone dust as you specify.

The meter would be located outside the building as you prefer, and I will supply and fit a suitable meter box for you too. [they supplied teh meter box in the end for free!!]

I have also included for you a list of the equipment that I would like to use if possible with this new supply. I have done my best to make this list as complete and detailed for you as I can.

Three phase loads;

1, One MIG welding machine.                                                       19 AMPS = 13.2 KVA.

[Please note that this is a “true” three phase machine [unlike most welders] Therefore, according to the makers plate, at the “full throttle, “intermittent rating” it draws 19 Amps and at the machines more usual maximum “continuous rating” it draws just 13 Amps]

2, One lathe, DOL. [with clutch to reduce starting current]     7.1 AMPS = 4.9 KVA.

3, One milling machine, DOL.                                                            6 AMPS = 4.2 KVA.

4, One milling machine, DOL.                                                         4.8 AMPS = 3.3 KVA.

5, One shaping machine, DOL.                                                       4.8 AMPS = 3.3 KVA.

6, One drilling machine, DOL.                                                          1.44 AMPS = 1 KVA.

7, One power hacksaw machine, DOL.                                          1.15 AMPS = 0.8 KVA.

Total three phase motor load [before diversity]                        44.3 AMPS = 30.7 KVA

Starting and stopping of motors etc;

It would be completely meaningless for me to give a list of “stops and starts an hour” for each machine, because this installation is for my own use, in a building owned by me. [The building will not be rented out or anything] therefore, I am the ONLY person that will be using this equipment, apart from on rare occasions when I may have a second person to assist me.

Because machine tools of this type cannot just be left to “get on with it” while you do something else, out of a total of seven machines [motors] generally, only one machine will be in use at any one time, up to a maximum of two machines in use simultaneously.

What I will do instead then, as it seems to be more sensible, is to give you a “worst case scenario” for the largest motor used, and the MIG welding machine.

Largest motor would be 4.9 KVA [7.1 AMPS] on the lathe, with about, say, four stops and starts an hour [while it was being used]

Welder would be, worst case, [maximum output] 13.2 KVA [19 AMPS] with about, say, four welds, each of about two minutes duration an hour, although this would be infrequent, with this machine only being used for perhaps an hour once a month.

As the motors are all mounted on machine tools, [as opposed to compressors and pumps and the like] they all start “off load” as it were, so starting currents should be relatively low.

Single phase 400V loads connected “line to line”

1, Power

This will be a “Reduced voltage”  110V CTE system used to power small “hand held” power tools such as angle grinders, electric drills and portable floodlights.

This circuit will be fed from a 400V “line to line” connected transformer of 5 KVA rating, supplying four BS EN 60309, 16 Amp socket outlets, wired on two radial circuits.

Although there will be four 16 Amp sockets, regulations specify that the maximum value of protective device for this type of socket circuit is limited to 20 Amps. This gives a total of 40A @110V and so a maximum output available, spread across the two circuits, of 4.4 KVA.

This gives an input power requirement of about,                                      12.3 AMPS = 4.9 KVA

Single phase loads [230V line to neutral]

1, Heating

A propane space heater, so only about 80 VA for the 110V fan motor

2, Lighting

Six, 5 foot, 230V 65W fluorescent lamps, [plus allowance for PF]                 3 AMPS = 700 VA

Total connected load [before diversity] = 36.3 KVA

Allowance for Diversity

It would be completely misleading to try to calculate diversity for this installation using the usual formula for motors [100% X +80% Y +60% Z] as this assumes that all [or nearly all] motors would be in use at the same time.

This would definitely not be the case with this installation, because as I have explained, there will only be me, or very rarely, maybe one other person using the equipment, and as I say, machine tools of this type cannot just be left to “get on with it”.

Therefore, there can only ever be two items of equipment, [out of a possible seven] in use at any one time.

So, once again, I have gone for a fairly “worst case” scenario, and I have calculated diversity as follows;

100% of largest load [welder]                                                                 19 AMPS = 13.2 KVA

plus;

100% of largest motor [lathe 4.9 KVA]                                                    7.1 AMPS = 4.9 KVA.

plus;

100% of single phase loads [lighting]                                                          3 AMPS = 700 VA.

and finally;

25% power [the 110V power tool sockets]                                                  3 AMPS = 1.2 KVA.

[Might possibly have two “floodlights” powered by the above going at same time]

Total ADMD is therefore = 19.95 KVA

Total line currents are, at ADMD, [with the 400V “line to line” 110V transformer connected across two phases and the single phase lighting “line to neutral load” on the third] rather miraculously perfectly balanced at;

1,                     29.1 AMPS

2,                     29.1 AMPS

3,                     29.1 AMPS

Finally, I do not know if it makes any difference, but this equipment would be used in the main, between the hours of 10-00 in the morning and about 15-00 in the afternoon, and I would estimate that total usage would be maybe three or four hours a day, on several days a week.

I have tried my best to give you every bit of information that I can think of, but if there is any other information that you need, or any problems at all, or any other help that I can give you, please email me on j***.l******@n*******.com or write to me at the above address.

Finally, I have read the notes of guidance, and agree to Western Power Distribution’s terms and conditions.

Thank you very very much.

John lewis

It worked for me!!!!!

P.S. Shame i forgot to mention to them about the 400 volt single phase welders that draw 84 Amps and the rest of the silly things I got!!! They do not like welders!!!!!!!

john....

 
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As i thought it might help, i have posted a copy of my actual application to the DNO when i did mine. I have done applications for other people too the same way as it explains things much better than their "official" form for situations such as "one man" businesses.

As you can see there is quite a lot they need to know. i sent in my letter and a few days later went to see them to se if it was ok. I was told "Oh yes!! the planners say they have everything they could have wanted"

Total cost for mine with the 25 metre service cable, AND 25 metres of 4" duct, AND the meter box, was about £1500 INCLUDING the vat. I was well pleased!!!

Anyway, here is my actual application...

Dear Sir,

Please can you give me a quotation for a new three phase electricity supply to be connected to my workshop building situated to the rear of my property located at the above address.

I have supplied a plan of the site [Attached] and I have also tried to give you as much other information as I possibly can to assist you with this.

As can be seen from the attached plan, the service cable length from the proposed meter position to the boundary of my property with the pavement is just under 25 metres.

The service cable would be run underground, and I will dig the trench on my property myself, to the required depth, complete with stone dust as you specify.

The meter would be located outside the building as you prefer, and I will supply and fit a suitable meter box for you too. [they supplied teh meter box in the end for free!!]

I have also included for you a list of the equipment that I would like to use if possible with this new supply. I have done my best to make this list as complete and detailed for you as I can.

Three phase loads;

1, One MIG welding machine.                                                       19 AMPS = 13.2 KVA.

[Please note that this is a “true” three phase machine [unlike most welders] Therefore, according to the makers plate, at the “full throttle, “intermittent rating” it draws 19 Amps and at the machines more usual maximum “continuous rating” it draws just 13 Amps]

2, One lathe, DOL. [with clutch to reduce starting current]     7.1 AMPS = 4.9 KVA.

3, One milling machine, DOL.                                                            6 AMPS = 4.2 KVA.

4, One milling machine, DOL.                                                         4.8 AMPS = 3.3 KVA.

5, One shaping machine, DOL.                                                       4.8 AMPS = 3.3 KVA.

6, One drilling machine, DOL.                                                          1.44 AMPS = 1 KVA.

7, One power hacksaw machine, DOL.                                          1.15 AMPS = 0.8 KVA.

Total three phase motor load [before diversity]                        44.3 AMPS = 30.7 KVA

Starting and stopping of motors etc;

It would be completely meaningless for me to give a list of “stops and starts an hour” for each machine, because this installation is for my own use, in a building owned by me. [The building will not be rented out or anything] therefore, I am the ONLY person that will be using this equipment, apart from on rare occasions when I may have a second person to assist me.

Because machine tools of this type cannot just be left to “get on with it” while you do something else, out of a total of seven machines [motors] generally, only one machine will be in use at any one time, up to a maximum of two machines in use simultaneously.

What I will do instead then, as it seems to be more sensible, is to give you a “worst case scenario” for the largest motor used, and the MIG welding machine.

Largest motor would be 4.9 KVA [7.1 AMPS] on the lathe, with about, say, four stops and starts an hour [while it was being used]

Welder would be, worst case, [maximum output] 13.2 KVA [19 AMPS] with about, say, four welds, each of about two minutes duration an hour, although this would be infrequent, with this machine only being used for perhaps an hour once a month.

As the motors are all mounted on machine tools, [as opposed to compressors and pumps and the like] they all start “off load” as it were, so starting currents should be relatively low.

Single phase 400V loads connected “line to line”

1, Power

This will be a “Reduced voltage”  110V CTE system used to power small “hand held” power tools such as angle grinders, electric drills and portable floodlights.

This circuit will be fed from a 400V “line to line” connected transformer of 5 KVA rating, supplying four BS EN 60309, 16 Amp socket outlets, wired on two radial circuits.

Although there will be four 16 Amp sockets, regulations specify that the maximum value of protective device for this type of socket circuit is limited to 20 Amps. This gives a total of 40A @110V and so a maximum output available, spread across the two circuits, of 4.4 KVA.

This gives an input power requirement of about,                                      12.3 AMPS = 4.9 KVA

Single phase loads [230V line to neutral]

1, Heating

A propane space heater, so only about 80 VA for the 110V fan motor

2, Lighting

Six, 5 foot, 230V 65W fluorescent lamps, [plus allowance for PF]                 3 AMPS = 700 VA

Total connected load [before diversity] = 36.3 KVA

Allowance for Diversity

It would be completely misleading to try to calculate diversity for this installation using the usual formula for motors [100% X +80% Y +60% Z] as this assumes that all [or nearly all] motors would be in use at the same time.

This would definitely not be the case with this installation, because as I have explained, there will only be me, or very rarely, maybe one other person using the equipment, and as I say, machine tools of this type cannot just be left to “get on with it”.

Therefore, there can only ever be two items of equipment, [out of a possible seven] in use at any one time.

So, once again, I have gone for a fairly “worst case” scenario, and I have calculated diversity as follows;

100% of largest load [welder]                                                                 19 AMPS = 13.2 KVA

plus;

100% of largest motor [lathe 4.9 KVA]                                                    7.1 AMPS = 4.9 KVA.

plus;

100% of single phase loads [lighting]                                                          3 AMPS = 700 VA.

and finally;

25% power [the 110V power tool sockets]                                                  3 AMPS = 1.2 KVA.

[Might possibly have two “floodlights” powered by the above going at same time]

Total ADMD is therefore = 19.95 KVA

Total line currents are, at ADMD, [with the 400V “line to line” 110V transformer connected across two phases and the single phase lighting “line to neutral load” on the third] rather miraculously perfectly balanced at;

1,                     29.1 AMPS

2,                     29.1 AMPS

3,                     29.1 AMPS

Finally, I do not know if it makes any difference, but this equipment would be used in the main, between the hours of 10-00 in the morning and about 15-00 in the afternoon, and I would estimate that total usage would be maybe three or four hours a day, on several days a week.

I have tried my best to give you every bit of information that I can think of, but if there is any other information that you need, or any problems at all, or any other help that I can give you, please email me on j****.l******@n*******.com or write to me at the above address.

Finally, I have read the notes of guidance, and agree to Western Power Distribution’s terms and conditions.

Thank you very very much.

John lewis

It worked for me!!!!!

P.S. Shame i forgot to mention to them about the 400 volt single phase welders that draw 84 Amps and the rest of the silly things I got!!! They do not like welders!!!!!!!

john....
You are one handy lad. :)

 
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I do try!!!

I just got their form and thought as it was not really applicable to me i would try to give all the information they asked for, but explain the situation better. It obviously worked!!

If anyone wants to copy it and adapt it to what they want to do, then feel free!!!

john..

 
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