Underground SWA Cable

[Engineer54]

70mm 2 core SWA has a CSA of armouring of 84mm2 ,with 70mm 2core the required CSA of the armouring would be 79mm2 so using 70mm two core SWA will be fine.

Only as the cables CPC, If any main bonding is involved then it will not comply!! BTW the CSA of armouring on a 2 core XLPE swa cable (which is now what you would receive from the wholesalers unless you specify PVC insulated) is 80mm...

With the sort of distances were talking about here, i'd still be calculating if that SW armouring is of a suitable size, even as a CPC!!

 

[skyline2500cc]

Hi Darkwood
We have calculated the load to be approx 5Kw and its actually a service building, so it will have some building services which will need to be earthed.
As I understand it if we cannot obtain the desired Zs value from the DNO, then we would install a separate earth and treat the service building as a TT system.
Is that not how you see it?. I look forward to hearing from you
Skyline2500cc

 

[Darkwood]

Can you show your VD calcs please and is lighting load included - at that distance you may be pushing it with 5KW ? I did a quick rough calc and get nearer 3kw hence my comment on the kettle.
For us to comment we need to know how your arriving at these figures.

Your use of the word Approx also means I would be figuring room for expansion within reason

What is the measured Ze at origin and what calculated Zs do you get + what is the nature of the OCPD and its type.... rather than using terms like 'if we cannot meet Zs' why not estimate it once you have selected your cable of choice.

 

[richy3333]

OK, maybe a dumb question but wouldn't it possibly be cheaper to get Hydro to put in a separate/new supply into this building (subject to the overhead cables, transformers etc)?

 

[SPARTYKUS]

OK, maybe a dumb question but wouldn't it possibly be cheaper to get Hydro to put in a separate/new supply into this building (subject to the overhead cables, transformers etc)?

Must be worth a shot!

 

[skyline2500cc]

The charges for works associated with new supplies are extremely expensive here, and hence why we are looking to putting an underground cable in.

 

[shanky887614]

have you checked how much if you dig the trench and supply the cable etc.

yeah its expensive in inverness they must have spent a fortune when they upgraded all those overhead lines.

i drove past it last year and they dwarfed the old ones (are they 133kv or higher im not what exactly, we dont touch distribution)

 

[SPARTYKUS]

Good advice above ^^^^^^^^^

 

[shanky887614]

my great aunt owns a chalet up in avimore a short drive from inverness so i can understand when you say its very expensive.

just so we are on the same page, how much were you quoted for say a 60a supply?

 

[telectrix]

one of my clients needed a 3 phase supply. 400 yards from nearest pole. he dug the trench himself. still cost him 15K.

 

[skyline2500cc]

We already have the supply and it was installed by others with cost unknown. We install new LV plant and historically it can cost thousands to get a supply from an existing transformer to a new location.
I was once quoted £600 to remove the meter and cutout so that we could replace the backboard with new because it was wood and had rotted away.
It took the guy two hrs tops from leaving his premises to returning.

 

[Silly Sausage]

have you checked how much if you dig the trench and supply the cable etc.

yeah its expensive in inverness they must have spent a fortune when they upgraded all those overhead lines.

i drove past it last year and they dwarfed the old ones (are they 133kv or higher im not what exactly, we dont touch distribution)

Do you mean these Muther F£$%ers?
Benvironment ? Scotland, meet your giant new pylons

So they can flog us all their Green power.

 

[shanky887614]

Do you mean these Muther F£$%ers?
Benvironment ? Scotland, meet your giant new pylons

So they can flog us all their Green power.

thats the one.

i past them on a drive from glasgow to avimore.

and its 400kv, i thought it was a big one

 

[Knobhead]

Do you mean these Muther F£$%ers?
Benvironment ? Scotland, meet your giant new pylons

So they can flog us all their Green power.

Bloody typical environmentalists. We need more renewable energy but we don’t want the means to transport it.

They’d moan if a damn big trench was dug to bury cables.

 

[telectrix]

al i can say to these whingers is " bin your washing machine/tumble dryer/range cooker. do the washing on a stone by the river and cook over an open fire in the back yard".