New supply

[Blue Duck]

That's Some expensive cable!

Maybe cheaper to build one of these???

 

[Peter44444]

Sure is! About 20-30pounds per meter at a guess.. Makes it 6-9 grand. Ouch! Still if 100A TP gives me 300A SP then I could cut down to 50A-60A TP which would still give me plenty for my needs. And may half the cost of the cable.

When you request three phase for a supply could you request a 60A supply to your meter box or is 100A the standard amount supplied?

blue duck what the heck is that? A lightning gatherer??

 

[ProDave]

Just to clarify in case there is any confusion.  100A 3 phase will enable you to have three separate 100A single phase consumer units with their associated circuits, but you can NOT combine them into a single 300A single phase supply (there would be a very big bang if you tried)  baddayexplode


 

 

[Peter44444]

Thanks prodave I will remember that. So 60A supply gives me 3x 60A single phase circuits if needed. 

So so back to basics. 

1. Could I ask for a new seperate 150A SP supply to a second meter? Or will supply company only supply 100A?

2. Could I ask for a 60A TP supply to a second meter?

3. Which would be more expensive for a. Supply b. 300m underground cable cable c. Installation around the yard.

if opinions could be given on these three questions that would help me out a great deal.

Thanks

 

[Sidewinder]

Why do you need a 150A 1ph supply?

This is senseless to me.

Sorry.

IF, you really want 150A of supply capacity which is over 34kVA, then you really need to go to the DNO because it is doubtful that you will be able to take that from the local supply network as it stands, it would potentially throw the network off balance.

What do you have that needs such a massive 1ph supply?

 

[Peter44444]

Ok fair point sidewinder I'll put down what I need to get out of this new supply.

30x10A sockets

8x16A sockets

2x 32A sockets (for the welder)

4x6A lighting circuits.

i would like to run a winch for my slipway but haven't looked into this yet it's difficult without TP. Not crucial...

The loads in a boatyard are pretty light generally. As customers are only about occasionally. They Only leave things like battery chargers on all the time. But they all need personal 10A supplys to run angle grinders and similar power tools when they need them.

from what I've gathered about diversity it's sounds like it's up to the opinion of the sparky as to how many sockets can be put on a 100A supply.

 

[ProDave]

You don't just add up the total load of all the sockets, you apply diversity. As you say, nobody uses much power for most of the time.

I take it this is more than just a boat yard and you are talking individual hook up's for the boats, more of a marina?

Out of interest (being a sailor myself) where are you?
 

 

[Peter44444]

No it's just a small boatyard situated in Essex. With mudberths a couple of pontoons and jetties. Serving say 15 boats shoreside then another 20 boats on the hard standing. But this will hopefully grow a little so I'd like to future proof if I can. I have three workshops (wood shop, metalshop and general) two stores and one site office. I have no employees but get the occasional subcontractor to share the workshops. The current required from the supply isn't going to be massive but I do need a lot of sockets. 

Is the general opinion here that a 100A single phase would probably be suitable for my needs?

 

[Lurch]

When you request three phase for a supply could you request a 60A supply to your meter box or is 100A the standard amount supplied?

You would get whatever you asked for, as long as the network could support it, but usually it would be a 100A supply unless there are capacity issues. IF you only wanted 60A (to reduce the cable size) you would just fit 60A fuses in your switch fuse that would be next to the meter supplying the sub-main.

1. Could I ask for a new seperate 150A SP supply to a second meter? Or will supply company only supply 100A?

2. Could I ask for a 60A TP supply to a second meter?

If you wanted more than 100A single phase then you would usually go to 3 phase and split the loads amongst the 3 phases. Single phase supplies >100A are rare. There is no point in having 2 supplies.

3. Which would be more expensive for a. Supply b. 300m underground cable cable c. Installation around the yard.

Depends on exactly what you do, could be any of them.

Is the general opinion here that a 100A single phase would probably be suitable for my needs?

I would probably advise you to go for the 3 phase supply (which would probably be 100A unless there are capacity issues on the network/transformer upgrades & associated costs were prohibitive etc). This would save you running out of capacity again in the future.

You could probably manage on a 100A single phase supply, but for how long?

Also with the cable run, it might cost more now to install a sub-main capable of taking the full 100A but in the future you might find it will be required and then it will cost a lot more to dig it up and upgrade it. If your house is wanting 60A+ and then there is 3 phase equipment in the yard it doesn't leave a lot of room for anything much, even with diversity there is still a point at which you could on occasions see issues with a limited supply.

 

[ProDave]

No it's just a small boatyard situated in Essex. With mudberths a couple of pontoons and jetties. Serving say 15 boats shoreside then another 20 boats on the hard standing. But this will hopefully grow a little so I'd like to future proof if I can. I have three workshops (wood shop, metalshop and general) two stores and one site office. I have no employees but get the occasional subcontractor to share the workshops. The current required from the supply isn't going to be massive but I do need a lot of sockets.

Is the general opinion here that a 100A single phase would probably be suitable for my needs?

Are they leisure boats? Or live aboard house boats, there is a BIG difference in likely demand.
 

 

[Peter44444]

Here's the picture as requested 

thank you for that last post lurch that was very informative. I feel more confident about contacting uk power networks now.

100A three phase is the ultimate for me then. I wonder as a 300m of 120mm 5 core would be very expensive up to £9k. I could see if a HV line could be run nearer to my site from the farmers field. It might be similar in cost and it would save me digging up 300m of track.

interestingly my a family member has just had a 300m cable put in as a feed to a new build house. It's a 100A single phase supply. When the request was put in two options and quotes were given. A. The 300m LV cable across the property to the site. Not including digging trench £10k. Or B. Extend the HV line across a neighbours land to the new build and thereby reduce the LV cable to 20m or so £13500 

so I think it might be an option for me rather than lay a monster cable underground.



Hi prodave no houseboats currently and no want for them. Too much hassle! Purely leisure use 

 

[Andy™]

looks like a TP supply with a transformer between 2 phases. @misssweden could probably confirm that

 

[Peter44444]

Purely Out of curiosity I know it's uk power network gear but does anyone know if that transformer be used to give TP 100A? Or would it get chucked and a different one put up. 

 

[Andy™]

it only has 2 inlets, so cant be used for TP

 

[ProDave]

That's a single phase transformer.  they would have to install a different one for 3 phase.

when I was getting prices for my new house it was interesting to work out the mindset of what they were offering.  There were presently 7 houses sharing a 100KVA transformer, my new house is the 8th one. So the default that they offered me was 12.5 KVA which equated to about 54 amps.  I am absolutely certain if I had asked for a greater capacity, there would have been an addiotional cost to upgrade to a bigger transformer.  But when it was connected it has the same 100A fuse as anyone else so I could draw 23KVA, just as long as all 8 houses don't do that at the same time.

 

 

[Lurch]

120mm 5 core

That is a very non stock cable, usually it would be 4 core and a separate earth or TT (which would be required on the marina anyway).

Or would it get chucked and a different one put up.

Yes.

 

[Peter44444]

ok here's another question. If I got my 100A TP I think that would be enough to do the yard and my house. So would I ditch my current single phase supply completely? It would save paying two bills. Or is there any benefit to having the three phase supply for the yard and keep the old 80A supply for the house? 

 

[Lurch]

So would I ditch my current single phase supply completely?

Yes.

Or is there any benefit to having the three phase supply for the yard and keep the old 80A supply for the house?

Not really.

 

[Tony S]

Purely Out of curiosity I know it's uk power network gear but does anyone know if that transformer be used to give TP 100A? Or would it get chucked and a different one put up. 

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.

 

[Sidewinder]

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.