Trying to get my head round Part P

[Woodendhead]

Just been reading the Part P and wondered I am okay to replace a cable that is damaged, but what if I discover a cable that is obviously under-rated? I am guessing I am not allowed to do the work unless I turn the power off and damage it first or it started to melt. But then I would have to replace it with the same under-rated cable. Thus to do it right I would have to notify. Would I get way with a notification that stated Replaced 1mm cable for a 2.5mm cable on the first floor ring main following the same route.

This might sound like that would not happen but I have had to have replaced the supply to the detached garage as it was a 2.5 mm unfused spur supplying 3 double sockets and the lights for a second CU and armored cable fused from the main CU (no idea what size as I dug the trench that is all before I get jumped on)

I am also very supprised to see I can replace my electric shower surely that is a mistake? I can't think of a place where it is more vitial to be 100% things are done just right.

 

[plugwash]

Afaict there is no requirement when replacing damaged cable that the new cable be the same size as the old.

 

[Woodendhead]

Replacig the cable for a single circuit only, where damaged, for example, by fire, rodent or impact (a)

(a) On condition that the replacement cable has the same current-carying capacity and follows the same route.

I think the words "the same" do cover that one it does not say "the correct" or "with the current standard of".

In reality I guess I should replace it correctly claim damage and forget about difference who would know anyway to prove anything.

 

[Stoday]

Note (a) in Table 1 of the Approved Document to part P, "On condition that the replacement cable has the same current-carrying capacity and follows the same route."

However, the purpose of the Approved Document is to explain the legislation, not to substitute another version of it. The actual Building Regulation says that you don't need to notify to replace a damaged cable. No mention of a capacity constraint. So go ahead. Normally the Approved Document is appropriate, but it's not in this case.

 

[ban-all-sheds]

As Stoday says - you really do need to understand the difference between Approved Document P (you should particularly note the 3rd paragraph on p3) and the actual Building Regulations.

 

[Woodendhead]

That made more sense I also note that the same route is also not part of it so a slight change to the route due to access to the original route is also okay so long as it means the IEE guidelines.

This is all just me getting my head round some of it and it not making any sense, most of the stuff in the approved doc and the regs are almost word for word so why change that one so much.