cable runs

[makeshift]

i am running swa cable to my summer house would 2.5 be large enogh for a 80 foot run

 

[ban-all-sheds]

Yes....

No....



Maybe.

 

[makeshift]

thanks for that great picture lol

 

[makeshift]

Yes....

No....



Maybe.

thanks for picture made me laugh

 

[ban-all-sheds]

Seriously, the size of the load is vital info, not just regarding the absolute capacity of the cable but also the limits imposed by volt-drop.

And even when you've worked that out, unless digging out several tons of earth is something you'd do for pleasure, consider putting in a larger cable than you think you need right now in case you ever need more in the future....

 

[Chri5]

Cable Type Twin and Earth SWA PVC SWA 3 Core
Underground
Circuit Type Non-Lighting Circuit Lighting Circuit
Ambient Temperature 15
Number of Circuits 1
Power 7000 Watts
Voltage 230 Volts
Length 30 metres

Required Cable Size 10 mm
Voltage Drop 3.47 Volts.
Percentage Drop 1.5%
Current Load 30.0 Amps
Max Cable Load* 31.5 Amps

 

[ban-all-sheds]

That looks like a C&P from the TLC website, but I don't get the same results.

And BTW - I've not played with the new one, so I don't know if it has the same problem as the old one, but if you selected 3-core SWA that used to do 3-phase calculations - to get the right answers you had to pick 2-core, even if you were going to use 2-core...

 

[AMEdinburgh]

Is the formula for your calcualtion on-line somewhere Chri5?

I reckon the SWA running to my garage (supplying a two, lights and sockets, breaker consumer unit) is only 4mm on a 20A breaker on the RCD side of my split consumer unit. Is this a concern? Was installed prior to me purchasing the house in 1995

 

[Chri5]

It is indeed the TLC 17th ed new calc tool.

Go to TLC, click cable, click swa, click cable calc

 

[AMEdinburgh]

Thanks Chri5, my 4mm seems to be adequate in respect of the parameters requested.