What size is this sheathed copper imperial cable?

[Storm93]

Hi guys , trying to determine the size of this imperial cable, 17mm diameter , what could the circumference be if it were double insulated? And what would be the equivalent cable now to use?

 

[telectrix]

35-50mm??? what is the ratingof the OCPD?

 

[snowhead]

The first pic showing the calipers reading 30.7 is wrong.
The calipers are being wrongly used on the internal measurement side not the external as in pic 2 and 3.

 

[westward10]

Unless you are physically on the conductor and not the insulation you won't get a realistic size.

 

[snowhead]

If it was single insulation it's around 95mm²
So if sheathed as well probably 70mm²

But as W10 above, you need to know if it definitely is sheathed and see the copper

 

[Storm93]

If it was single insulation it's around 95mm²
So if sheathed as well probably 70mm²

But as W10 above, you need to know if it definitely is sheathed and see the copper


View attachment 91329

 

[Storm93]

35-50mm??? what is the ratingof the OCPD?

200 amps per phase

 

[telectrix]

so the ideal size cable would be 70 mm (200A).

 

[Storm93]

so the ideal size cable would be 70 mm (200A).

May I ask how you got to that conclusion???

 

[ipf]

May I ask how you got to that conclusion???

Professionally.....from available information... cable suitably rated to carry 200amps

 

[telectrix]

cable rating table F4(i) OSG . (50mm would just make it in free air).

 

[Storm93]

Professionally.....from available information... cable suitably rated to carry 200amps

Can I ask , so based on your information , if I needed to extend or rewire part of the ryfield mains cable , a suitable sized cable based on what’s there already would be 70mm ?

 

[ipf]

Can I ask , so based on your information , if I needed to extend or rewire part of the ryfield mains cable , a suitable sized cable based on what’s there already would be 70mm ?

Sorry, but I haven't got enough info to say. We are going off one piece of info but, with any supply, there are many things to take into consideration, especially working on a 200amp 3 phase input.

 

[Petej999]

If it was single insulation it's around 95mm²
So if sheathed as well probably 70mm²

But as W10 above, you need to know if it definitely is sheathed and see the copper


View attachment 91329

!19/064"

 

[Storm93]

!19/064"

What makes you say 19/064 which is 38mm?

 

[telectrix]

What makes you say 19/064 which is 38mm?

110 years of experience. (sorry pete, couldn't resist. ??.).

 

[Storm93]

110 years of experience. (sorry pete, couldn't resist. ??.).

So what makes you say 19/064, any reason ?

 

[telectrix]

!19/064"

got to be bigger than that for 200A.

 

[Lucien Nunes]

Based on the pics on the other thread showing each phase feeding two 60/80A Series 7's, the design load on it is no more than 160A and might be as low as 120A. The upstream 200A fuses only need to protect it against fault, not overload. In that thread I think it's fairly clear the reds are not sheathed, and we can see in the above pic that the neutral is not.

With the extra pics to look at and the O/D measurement I'm not sure that the concensus we reached there, i.e. 19/.064 is correct. It could be 0.1 sq. ins., unfortunately I'm nowhere near my books of 1960s tables to look it up.

 

[Petej999]

got to be bigger than that for 200A.

A long time TEL