Imperial pyro advice

Teddy Lop · Oct 6, 2019

Can anyone identify what this is and what its current carrying capacity should be? Being a sprightly 41 imperial sizes aren't my thing and I can't find anything on the net.

2 core pyro about 13mm diameter, gland marked 465, seems to be about 10mm-ish equivalent.

Backstory if you want it is electric board have condemned the setup which is 4x pyro service head to meters on floor above, then pyris from meter to flats. I'm still trying to ascertain exactly how much is "condemned" as if these pyros are no longer good for 60 amp that's half the flat conversions in London!

[ElectriciansForums.net] Imperial pyro advice

Pete999 · Oct 6, 2019

Teddy Lop said:
Can anyone identify what this is and what its current carrying capacity should be? Being a sprightly 41 imperial sizes aren't my thing and I can't find anything on the net.

2 core pyro about 13mm diameter, gland marked 465, seems to be about 10mm-ish equivalent.

Backstory if you want it is electric board have condemned the setup which is 4x pyro service head to meters on floor above, then pyris from meter to flats. I'm still trying to ascertain exactly how much is "condemned" as if these pyros are no longer good for 60 amp that's half the flat conversions in London!

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Leaving the MI aside, I would guess that the state of those pvc/pvc entries are suspect, along with the cables connected into the Henley blocks (Mechanical OVC cover stripped to far)
I would guse you would need some information from a MICC manufacturer to enable you to assess the cable size. That's one rough old install you have there Teddy.

westward10 · Oct 6, 2019

It actually says 469 which is 0.01 inch or 6.45mm metric equivalent. See it on this Table.

snowhead · Oct 6, 2019

465 is the imperial outer dia in thousands of inch so = 0.465in (note 469 is the same)
In the table below comes out to equivalent of 2 x 6.45sq.mm cores rated at 56amp.
(spent too long searching, Westward beat me)

Teddy Lop · Oct 6, 2019

Thanks guys that's super.

freddo · Oct 6, 2019

I'd recommend one of the old MI handbooks for information on all types of MI cable. I also have the Pyrotenax version that I keep in the van. It has very detailed information on installing, testing and repairing MI cable.