5 core SWA 120mm pvc cable

[Spoon]

What size cable would he need to future proof for that?

This is down to the electrician who will be signing off the design for this job.

 

[buzzer123]

Op should you not ne asking you spark that qestion.

Hi Buzz,

Thank you for your response.

I will ask him but it’s really good to get the opinions of several qualified expert‘s because several brains is better than one

 

[MJPD29]

No matter what you did this is going to be a very expensive cable. I'd ask the electrician to do the cable calcs for you to make sure

 

[davesparks]

Hello all
Thanks for your responses.

I believe that is 100 A total Split across three phases.
Client is talking to UK power networks about upgrading transformer to have 100 A from each phase.

What size cable would he need to future proof for that?
Thank you.

He needs to decide what is happening with UKPN first before worrying about what size of cable to get.
But before that you need to know what size supply is actually required.
There's no point getting a bigger transformer installed if the current supply will do the job.

To get 100A over that distance I would hazard a guess at 2x 120mm in parallel, but that is just a guess.

 

[westward10]

Get a specialist cable installation contractor in. Pulling cables over that distance is going to be some task. They will calculate it, pull it and connect it.

 

[buzzer123]

He needs to decide what is happening with UKPN first before worrying about what size of cable to get.
But before that you need to know what size supply is actually required.
There's no point getting a bigger transformer installed if the current supply will do the job.

To get 100A over that distance I would hazard a guess at 2x 120mm in parallel, but that is just a guess.

Thank you all for your responses, really appreciated. Regardless of the cable that will be finally specified I am still keen to know of the most cost effective electrical wholesalers from which to gain some prices any advice would be greatly appreciated

 

[westward10]

You are going to need to phone around. Try the internet first to find who deals with such sized cables, knowing the size will be handy. Large sizes and long lengths people should be competitive, ball park £8-10k that is without delivery because it ain't fitting in the back of a a Transit. That is for 120mm.

 

[davesparks]

Thank you all for your responses, really appreciated. Regardless of the cable that will be finally specified I am still keen to know of the most cost effective electrical wholesalers from which to gain some prices any advice would be greatly appreciated

Phone a few wholesalers or even cable suppliers such as Cleveland cables to get quotes.

It seems a bit weird to me that teh electricina won't supply it

 

[DPG]

Are we getting the full story here? Am I just being a bit suspicious?

 

[buzzer123]

The electrician will supply it - well he will put the client on his kew account as long as he pays as the cables not in his budget (and rightly so as I could not afford it either!!) nothing suspicious DPG trying to get names of some good wholesalers that's it - plain and simple - thought i could do better than kew………….. but also learning things from all you helpful folks so when I interact with the sparky I am in possession of actual knowledge - nothing I hate more than being pig ignorant and as I have said the clients become my friend over the years and do not want him to get stung by having someone spec it wrong and get it wrong. Will get a second quote for him now as some of you have made points this contractor did not mention and wont another opinion
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Are we getting the full story here? Am I just being a bit suspicious?

No your right to be suspicious I am an electrical double agent that lurks on forums asking questions that only a non qualified lay person would ask?? I am putting the cable underground mate - only want to dig it and do it once!! got a big reel organised from a mate to help distribute the cable and don't like messing about that why i thought I would ask for help.

 

[westward10]

Good luck pulling that size of cable over 250m.

 

[davesparks]

The electrician will supply it - well he will put the client on his kew account as long as he pays as the cables not in his budget

got a big reel organised from a mate to help distribute the cable and don't like messing about that why i thought I would ask for help.

This still doesn't make much sense to me, if its left to the client to arrange the supply of the cable then it really does suggest that the contractor is not used to doing this kind of work or using this size of cable.

What do you mean by a big reel? You're going to need to be careful how the cable is pulled in or laid as it is surprisingly easy to damage big armoured cable when doing this.
Cables can be damaged by pulling too hard on them and by incorrect attachment of the pulling rope, cable manufacturers will state the maximum pulling force and method of attaching the rope.

Are you aware that the cable needs to be laid in soft sand to avoid damage to the sheath, marker tape or tiles will need to be installed and sheath tests will need to be done to ensure that no damage has occurred to the sheath during laying the cable.

 

[westward10]

The reality will hit home when a low loader arrives with the cable.

 

[Robson689]

The reality will hit home when a low loader arrives with the cable.

At least 3 tonnes of cable I reckon

 

[buzzer123]

This still doesn't make much sense to me, if its left to the client to arrange the supply of the cable then it really does suggest that the contractor is not used to doing this kind of work or using this size of cable.

What do you mean by a big reel? You're going to need to be careful how the cable is pulled in or laid as it is surprisingly easy to damage big armoured cable when doing this.
Cables can be damaged by pulling too hard on them and by incorrect attachment of the pulling rope, cable manufacturers will state the maximum pulling force and method of attaching the rope.

Are you aware that the cable needs to be laid in soft sand to avoid damage to the sheath, marker tape or tiles will need to be installed and sheath tests will need to be done to ensure that no damage has occurred to the sheath during laying the cable.

Borrowing a trailored reel dispenser will tow with my 100hp tractor......was going to bury in soil thought armoured was tough......now your worrying me....will ascertain installation specs when cable is purchased so I do not f**k it up - thanks for the heads up
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was hiring a 13 ton machine for the second week to install the gate but looks like I may need a bigger boat

 

[davesparks]

Borrowing a trailored reel dispenser will tow with my 100hp tractor......was going to bury in soil thought armoured was tough......now your worrying me....will ascertain installation specs when cable is purchased so I do not f**k it up - thanks for the heads up

Armoured is tough in some ways, and not in others.
It can take a fair whack of an impact without suffering any damage, but drag it over a sharp object and the outer sheath can quickly be broken.
The biggest danger at installation is the outer sheath being damaged as water will get in even the smallest gap and the armour will rot away in a very short time.

 

[buzzlightyear]

I would go for a speaclist company for laying it , it amaze me when peaple say i will do it me self save the cost get some body in .

 

[buzzer123]

I would go for a speaclist company for laying it , it amaze me when peaple say i will do it me self save the cost get some body in .

With the greatest of respect Buzz - I am getting someone in to do live up the wire - I am a groundworks professional and installing a cable into a trench is not exactly testing i will be carefull and walk the trench to ensure there is nothing sharp in there - following davesparks advice i will now encase the cable in sand for belts and braces approach.
When I spoke to power networks guy he said they did not bother as the armoured was bulletproof and could just throw it in the trench and refill with the soil.
The ground here is clay with occasional flints so I will use sand.

 

[westward10]

Have you got plenty of cable rollers to prevent drag.

 

[Bobster]

Have you got plenty of cable rollers to prevent drag.

Definitly need rollers on this job.

Using even 200m of 4 core 120mm (can't find the weight for 5 core) cable will weigh just over 1480kg.

Not just damage caused by catching debris in the trench. At that weight, pulling with a tractor without rollers will likely stretch and damage the cable anyway.