what csa and material to enter

[sams]

Evening all,
I wonder if anybody could help me what to enter as the material and size of earthing conductor when 25mm steal conduit is used as earthing, so what is 25mm steal conduit equivalent to earthing conductor mm!
I am struggling to find out what to put down in cert.
Thank You in advace for your input

 

[MarkieSparkie]

Hi sams, 25mm Steel Conduit has the following CSA:
Light Gauge = 89mm[SUP]2[/SUP]
Heavy Gauge = 132mm[SUP]2[/SUP]
The minimum size of CPC when the line conductors are copper and the CPC is steel:
<16mm[SUP]2[/SUP] 70°C thermoplastic line conductors require a steel CPC of =>2.45 x line conductor CSA
<16mm[SUP]2[/SUP] 90°C thermoplastic line conductors require a steel CPC of =>2.27 x line conductor CSA
So either light or heavy gauge 25mm steel conduit easily complies with BS7671 543.1 as a CPC for PVC line conductors <16mm[SUP]2[/SUP].
On your TSR you should record the CPC as Steel and it's CSA, either 89mm[SUP]2[/SUP] or 132mm[SUP]2[/SUP] as appropriate.

 

[Knobhead]

That should go in one of the sticky threads Mark. Useful bit of info, if you could include 20mm it would be great.

 

[sams]

Thank you very much Mark and yes this info should be in one of the sticky threds as it is very useful for other users

 

[mogga]

I had a sheet with swa trunking conduit but Amtek haz a wizzzzard for that stuff

 

[MarkieSparkie]

That should go in one of the sticky threads Mark. Useful bit of info, if you could include 20mm it would be great.

Thanks Tony and Sams, I'll expand it later including 20mm.

 

[Knobhead]

I wonder what 3” steam pipe works out at?

Don’t laugh, I tried to use it with silicon-braided singles running through it. It didn’t last long, a 70-ton cane hit it!
Back to the drawing board
View attachment 9078

 

[MarkieSparkie]

Unable to edit the #2 post, so I have re-jigged and expanded the information here.
Cross-sectional area of BS EN 61386:2004, BS EN 50086:1994 and BS 4568:1970 steel conduit.

The CSA of 16mm steel Conduit:
Light Gauge = 47mm[SUP]2 [/SUP]
Heavy Gauge = 75mm[SUP]2[/SUP]
The CSA of 20mm Steel Conduit:
Light Gauge = 59mm[SUP]2 [/SUP]
Heavy Gauge = 107mm[SUP]2[/SUP]
The CSA of 25mm Steel Conduit:
Light Gauge = 89mm[SUP]2
[/SUP]Heavy Gauge = 132mm[SUP]2[/SUP]
The CSA of 32mm Steel Conduit:
Light Gauge = 116mm[SUP]2
[/SUP]Heavy Gauge = 167mm[SUP]2[/SUP]
The CSA of 38mm Steel Conduit:
Light Gauge = Unavailable
Heavy Gauge = 186mm[SUP]2 [/SUP]
The minimum size of CPC when the line conductors are copper and the CPC is steel:
<16mm[SUP]2[/SUP] 70°C thermoplastic PVC line conductors require a steel CPC of >=2.45 x line conductor CSA (16mm[SUP]2 [/SUP]PVC =>39.2mm[SUP]2[/SUP] minimum required)
<16mm[SUP]2[/SUP] 90°C thermoplastic PVC line conductors require a steel CPC of>=2.27 x line conductor CSA (16mm[SUP]2 [/SUP]PVC =>36.32mm[SUP]2[/SUP] minimum required)
<16mm[SUP]2[/SUP] 85°C rubber line conductors require a steel CPC of >=2.48 x line conductor CSA (16mm[SUP]2[/SUP] rubber =>39.68mm[SUP]2[/SUP] minimum required)
<16mm[SUP]2[/SUP] 90°C thermosetting XLPE line conductors require a steel CPC of >=2.47 x line conductor CSA (16mm[SUP]2[/SUP] XLPE =>39.52mm[SUP]2[/SUP] minimum required)
Therefore all the above steel conduit sizes/gauges easily comply with BS7671 543.1 as a CPC for the above types and sizes of line conductor.

 

[Ewathewoowoo]

Doing a conditions report on a old property and conduit used as cpc as was in the 60s.
Interesting i would like to understand were we get these figures from as the conduit there is 3/4" and 1"
Its a amazing place to test we have conversation charts as all MI are imperial so have to put down csa of coductors in mm2.
Could do with a spreadsheet to show all conduits and trunks cpc as well as old single wiring sizes as have to measue outside diameter to obtain ruff size anyone know of such a spreadsheet.

 

[telectrix]

for the cpc csa i would just enter "conduit". let some bugger else do the calcs if they are ----.

 

[Lister1987]

Doing a conditions report on a old property and conduit used as cpc as was in the 60s.
Interesting i would like to understand were we get these figures from as the conduit there is 3/4" and 1"
Its a amazing place to test we have conversation charts as all MI are imperial so have to put down csa of coductors in mm2.
Could do with a spreadsheet to show all conduits and trunks cpc as well as old single wiring sizes as have to measue outside diameter to obtain ruff size anyone know of such a spreadsheet.

Guidance Note 8 contains information regarding Steel conduit/tray/trunking equivalence, if I'm recalling correctly.

 

[Lister1987]

Use SWA as CPC, a guide to the acceptability of steel wire armour use as CPC.

SWA as the CPC? In most case it is fine to use the SWA as a CPC.

www.gadsolutions.biz

Contains some useful information garnered from GN1 & GN8