Electrical Cable Size?

NoseyMike2010

How do you calculate electrical cable size?

Can somebody provide me with an example. Mathematical formulaes are a big bonas.

2011

How do you calculate electrical cable size?

Cable size depends on many factors. The main ones are:

• Size of load (from this work out the current drawn)
• Length of run (ensure that volt drop is not excessive)
• Conductor material (normally copper, but sometime aluminium)
• Ambient temperature
• Insulation material
• Method of installation
• Grouping factor

Can somebody provide me with an example. Mathematical formulaes are a big bonas.

The ETCI reulations (ET 101:2008) have everything that you need.

I have all of this done out in a project I did from my college days. If you PM me an email address I can email it to you. All of the calculations are done for cable sizing for main distribution boards, sub distribution boards, and final sub circuits. Protective devices have been selected and there is a section on lighting calculations and emergency lighting.

NoseyMike2010

Cheers 2011,

Examples like that should help me. If I have more questions I am sure I'll be back to ask!

2011

Keep asking. I will try to answer.

2011

NoseyMike2010,

Email sent! Let me know how you get on

2011

Stoner

I can't find that thread where people posted websites that carried out the cable sizing.

Does anyone know the sites? I might add it to a resource sticky

2011

Try this:

http://www.electacourse.com/cableselector.html?type=Twin_Earth&application=conduit_wall&power=3.5&power_units=1000&voltage=230&length=20&min_cable_size=1.5&voltage_drop=7.6&percentage_drop=3.3&current=13.04

Stoner

I just did , it was rubbish lol.

only joking, thank you

2011

To be honest I think it oversized the cables!

NoseyMike2010

What is 2 Core, 3 Core, Multi Core cable? When is it used? And how is it different to stranded copper cable???

firemansam1

NoseyMike2010 wrote: »

What is 2 Core, 3 Core, Multi Core cable? When is it used? And how is it different to stranded copper cable???

2 core has 2 cores contained in the cable
3 core has 3 cores cointained in the cable
Multicore has multiple cores contained in the cable

They can be stranded or solid cores.

They are used everyday all over the world in electrical installations from the smallest to the largest.

Stoner

NoseyMike2010 wrote: »

What is 2 Core, 3 Core, Multi Core cable? When is it used? And how is it different to stranded copper cable???

solid core cables have less surface area compared to stranded cable, stranded and flex cables can carry more current than their overall CSA matched solid cable.

Having said all that NoseyMike2010 are you really just Nosey ?

NoseyMike2010

Wouldn't say Nosey ... just interested!!!

Moezlak

Could u send me some details on how to size cables please,moezlak

Moezlak

2011 wrote: »

NoseyMike2010,

Email sent! Let me know how you get on

2011

Sent it on to me please

Bruthal

Stoner wrote: »

solid core cables have less surface area compared to stranded cable, stranded and flex cables can carry more current than their overall CSA matched solid cable.

Yes another way of explaining it is a solid round conductor has most of its current flow on the outer part of the conductor, near or at its surface, so if you get the same size conductor in stranded form, each strand is now one of many in parallel, each like a circurlar conductor with its own individual surface for the current to flow along. So a stranded cable has a better capacity than a solid one. They also get a better connection as well at terminations.

jocotty

2011 wrote: »

Cable size depends on many factors. The main ones are:

• Size of load (from this work out the current drawn)
• Length of run (ensure that volt drop is not excessive)
• Conductor material (normally copper, but sometime aluminium)
• Ambient temperature
• Insulation material
• Method of installation
• Grouping factor

The ETCI reulations (ET 101:2008) have everything that you need.

I have all of this done out in a project I did from my college days. If you PM me an email address I can email it to you. All of the calculations are done for cable sizing for main distribution boards, sub distribution boards, and final sub circuits. Protective devices have been selected and there is a section on lighting calculations and emergency lighting.

Hi 2011

I hope you are well.

would it be possible for you to send me a copy of this project.

It would be a great help to me at the moment.

Please PM me , and I will give you my email address, and tell you why I need them.

thanks,
Jo

Stoner

yes 2011, I'd love that too

2011

Done