CSA and resistance of 20 & 25mm Steel Conduit

[Strima]

Can anyone point me in the right direction to find out the CSA and resistance of 20 & 25mm steel conduit?

It's for part of my 2396 project where I'm using the conduit as CPC, I'm happy enough with the calculations I just need some numbers to work with.

I've tried various manufacturers websites and come up short so if someone has any data sheets it would be appreciated.

Thanks.

 

[DavidSpark]

I did have a big table of the figures but I can't seem to find that, however I did find this.
IET Forums - CSA tables for steel conduit?? - http://www.------.org/forums/forum/messageview.cfm?catid=205&threadid=24288

GN1 seems to get named dropped a lot and if memory serves me correctly, they are at the back of that book.

Best of luck with your project!

 

[Strima]

Cheers mate, funnily enough I've been gazing at page 60 of GN1. It gives the minimum CSA but no resistance per meter which is what I need.

Although it does say refer to GN6 however I'm loathed to give the IET another £20 odd for another book, they've had enough of my cash already and will demand more next year!!!

Unless someone has the formulae to hand?

 

[DavidSpark]

I'd imagine that you could use the formula

R = ρ*L/A

With ρ being the resistivity of the material, L being 1 metre, A being the CSA in m²?

I have however found something that may help you, I don't actually know where the information for the table was sourced from, so you'll have to take it with a tiny pinch of salt and try and work back from there, perhaps try searching for the BS numbers and checking for a minimum resistance/m for it to comply.

View attachment ConduitCPC.jpg

View attachment TrunkingCPC.jpg

 

[Strima]

Cheers mate, that'll get me started.

 

[timbobelfast]

Grab yourself a copy of Guidance Note 8.

Is this for the electrical training centre project?

 

[Strima]

For my C&G 2396.

Was having a problem with a 16 amp TP-N supply for HVAC as the adiabatic wasn't giving me what I wanted.

Using the conduit as CPC soon cured that...

 

[Leesparkykent]

Table of Impedances of Conduit & Trunking - https://www.electriciansforums.co.uk/resources/table-of-impedances-of-conduit-trunking.64/

Posted in the resources area by @Sintra

 

[Leesparkykent]

Conduits for Earthing - http://myweb.tiscali.co.uk/gospry/gospry2_004.htm

 

[Strima]

Bang on, cheers @Leesparkykent

 

[netblindpaul]

@Strima,
I haven’t checked the links yet as I am traveling.
I would suggest that you verify that the data is correct somehow, so that you can reference it correctly.
All the information you need is in GN8.
Once I get to my laptop, maybe later tonight, but, probably tomorrow evening when I get back to my hotel, I will copy the relevant info from GN8 for you if you want.

 

[Strima]

@netblindpaul it would be greatly appreciated mate, the links seem pretty close to what I've been looking up on the net.

I would have thought manufacturers data sheets would have contain some specifications but as usual they seem to be coming up short.

Thanks again.

 

[netblindpaul]

@Strima,

Please feel free to PM me tomorrow evening to remind me.

I have a 7:00 am flight tomorrow morning and then back to the uk tomorrow evening so it’s going to be a long day.
I also have a lot going on, so a reminder will be useful!

 

[Strima]

Cheers mate, I won't hassle you too much, I know what those days are like!!!