Discuss Supplying electric 400 metres away in the Commercial Electrical Advice area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

ok, so ive made some more assumptions:

a) all of the loads will be small single phase loads, none more than 20A
b) they will be general building services: ie, lighting, power and heating
c) that there will be one circuit going to the first building, and then looping off to the second.
d) ive assumed a power factor of 0.8
e) ground temp of 20 degrees c at the highest (if the temp risesabove tis in the summer, then the heating will be off, and you wouldnt need air con so close to the sea anyway ;-)

its come up with a 3ph 32A supply at 35mm2. You would have to balance the loads and buy a 3ph board, but the savings would be enourmous on cable alone.
 
Last edited:
The buildings are sort of offices used for monitoring purposes.

The load has been calculates at 58A which is why we are looking at 63A supply. Thanks for your idea of the extra core for the earth but would the earth potential voltage be a lot different between the meter buildings and the proposed new buildings? There is just under 400m of made up land using rocks to gain the height. Probably 300m is a sea wall.

It is an unusual project - almost unique - as I do not think that using concrete which would be on a rock formation would be suitable. The rock under the concrete would dry out in dry weather thus reducing the efficiency of the earthing.

Any constructive suggestions welcome.

Also, as this is for a charity, is anyone interested in it?

Maybe a challenge for a college..............

Are you wanting to play poker with us where we show our hand and you keep yours hidden?

The load has been calculated at 58A - by whom and based on what?
 
It was someone just trying to find out the cable size and now they've gone of to spend £6k on Swa.

They should have hung around and found out they could have managed with 16mm t&E.
 
That is why it is crucial to have specs for something like this Lenny, I can't for the life of me see an office building having a total load of 58amps, unless it was a 3 story office block.

I don't think I would suggest a single phase supply with a 60amp load over 400mts, it is just not economical it would have to go to 3 phases


I've given up trying to 2nd guess posters that dont divulge enough info from the start, I feel, if this was genuine, the services of a competant spark/consultant would already have been engaged.
 
For a cable run of 400 metres, no way would i run a single SWA, it needs to be a parallel supply, which will reduce the overall size of the SWA cable considerably, etc.... So if a 120mm was called for, then replace with 2 X 3 core 50mm or 70mm depending on actual requirements and restrictions at the load end. As for the earthing arrangement i would be inclined to extend the supply earthing, and if possible explore the possibilities of adding TT earthing, be it Ufer, copper tape, rods etc, that can be connected to the MET of the two buildings.

Until we know more, these are just base line assumptions, to give the OP a little more thought, in to how to tackle such an installation....
 
We all wish the sea defence wall contained steel - that would make life a lot easier. The wall was built about 200 years ago from quarrying in the area and it carries a footpath and road across it.

The company operating across it is the oldest operating company in the world in its sphere and I am in the supporting charity company.

I will obtain the calculations and post them here as soon as I can. It is two single story offices, one of which is for battery supplies should the mains fail, but these offices are close to the sea and obviously need excellent insulation for low amounts of heating in the winter.
 
I wouldn't be basing a design, nor be doing a budget for a build/change on the basis of input from a number of "unknown" people on the web if I were you.

Suggest you post the location and get at least 3 people to come and have a look and provide written outline plans.
 
Since I fancy a guess, how about the Cob at Porthmadog, built in 1811? Not only a road and a footpath along it, but a very nice narrow gauge railway!

If this is for the Ffestiniog Railway Society, then any help is good, chaps.
 
Since I fancy a guess, how about the Cob at Porthmadog, built in 1811? Not only a road and a footpath along it, but a very nice narrow gauge railway!

If this is for the Ffestiniog Railway Society, then any help is good, chaps.









Do I signal a yes here? Maybe I have given away too many points!! :wink_smile: lol

The loadings

Lighting 1kw
Heating 6kw
IT 1kw
Kitchen & drain 3kw

Each building is 10m by 4m approx

Any constructive thoughts are welcome.
 
For me with that kind of loading you would be looking at nearer 40 amp rather than the 63 amp your were looking for. IMO diversity would get that to around 30 amps for commercial property, but make it 40amps for good measure.

4amps of IT is perhaps a little excessive as well and so is the 4amps for lighting. Heating will obviously be your main problem but a well built well insulated building will off set some of that.

Are the above figures combined or for each building
 
Have you considered a heat pump for heating rather than electric resistance heating?


That would be the ideal solution but, unfortunately, we do not own the shoreline either side to be able to use the sea bed.
 
Yes interesting thread, just info is so limited... if its a monitoring station you would need to know what is been monitored and if it uses power 24/7 (possible storage heating if daytime only), its possible the quoted demand is correct but need a breakdown, now this isnt my field so not sure on the regs here as it would be out of the scope of the 17th but is it possible to up the voltage then derate at offices... i would also be taking a minimum of 80amp supply with the suggested design load, you just know someone gonner stick an extra Heater or two on.
 
Last edited:
Yes interesting thread, just info is so limited... if its a monitoring station you would need to know what is been monitored and if it uses power 24/7 (possible storage heating if daytime only), its possible the quoted demand is correct but need a breakdown, now this isnt my field so not sure on the regs here as it would be out of the scope of the 17th but is it possible to up the voltage then derate at offices... i would also be taking a minimum of 80amp supply with the suggested design load, you just know someone gonner stick an extra Heater or two on.


Off-peak storage heating would need an extra circuit so a separate armoured cable - that is out of the question, I am afraid.

I totally agree with future proofing which is what we have done for the installation at the works on one headland, but we are talking about the other end of the causeway. Monitoring? well, just traffic really, everything goes on outside and it is really a controlling monitor station operating battery powered lights. The second room being the battery room.


The loadings

Lighting 1kw
Heating 6kw
IT 1kw
Kitchen & drain 3kw

Each building is 10m by 4m approx

Any constructive thoughts are welcome.
 
I never said off peak in seperate supply you just set up timer and contactor array then the front end meter would then be duel tarriff, thus only requiring the one supply.
 
Off-peak storage heating would need an extra circuit so a separate armoured cable - that is out of the question, I am afraid.

I totally agree with future proofing which is what we have done for the installation at the works on one headland, but we are talking about the other end of the causeway. Monitoring? well, just traffic really, everything goes on outside and it is really a controlling monitor station operating battery powered lights. The second room being the battery room.


The loadings

Lighting 1kw
Heating 6kw
IT 1kw
Kitchen & drain 3kw

Each building is 10m by 4m approx

Any constructive thoughts are welcome.

You really need to get somebody to come and LOOK at the site. Are you representing the organisation of trying to design it and sell to them?
 
You really need to get somebody to come and LOOK at the site. Are you representing the organisation of trying to design it and sell to them?



No - at this point in time, no outside contractors have been involved. I am part of the team in the charity for which my time is given free of charge.
 

Reply to Supplying electric 400 metres away in the Commercial Electrical Advice area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

YOUR Unread Posts

This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock