Protection for >3m tails

[telectrix]

Code 2 and a code 3 for no additional protection with it being T&E - presuming it's in a wall etc?

never presume. look what happened to the titanic.

 

[SJD]

Thanks for the additional replies.

To sum up, if I’ve understood correctly, for tails over the length permitted by the DNO (typically 3m), suggested EICR code:

	Cable not mechanically protected, e.g. T&E in walls	Cable is mechanically protected, e.g. SWA
Conductor size too small for DNO fuse rating, taking account of installation method(s)	C2 – needs fuse/MCB C3 – recommend RCD	C2 – needs fuse/MCB
Conductor size OK for DNO fuse rating, taking account of installation method(s)	C3 – recommend RCD	No code – though does not meet ESQCR

This always assumes you know the actual DNO fuse size, e.g. a 100A carrier will often have a lower rated fuse fitted, which might not be easily checked.

 

[Guest55]

i'd go along with that ^^^

 

[telectrix]

not 100% happy with the C2's. if the cable is, say, 16mm on a 100A DNO fuse, and has been in situ for years without any signs of damage, i'd lean more towards a C3.

 

[SJD]

I'm inclined to agree, if 16mm2 cable CCC can be as high as 94A for reference method E, it is not that far short of the 100A. The trouble with having just three codes to choose from, with something marginal, I find it can be difficult to decide which code.

A different example I’ve come across a few times recently is small amounts of visible (exposed) live cable or terminals on the suppliers equipment, e.g. on the fuse carrier or meter tails, trying to decide if it should be a C1 rather than C2.

 

[Andy78]

I'm inclined to agree, if 16mm2 cable CCC can be as high as 94A for reference method E, it is not that far short of the 100A. The trouble with having just three codes to choose from, with something marginal, I find it can be difficult to decide which code.

A different example I’ve come across a few times recently is small amounts of visible (exposed) live cable or terminals on the suppliers equipment, e.g. on the fuse carrier or meter tails, trying to decide if it should be a C1 rather than C2.

Accessible exposed live parts are always a C1, and in this case probably an emergency callout to the supplier/DNO.

 

[SJD]

Accessible exposed live parts are always a C1, and in this case probably an emergency callout to the supplier/DNO.

Yes, but I'm talking about quite small exposed parts, the question is whether they should be defined as accessible - comparing for example to an unenclosed choc block, a small one you can't touch the screws, make it large enough and perhaps you could.

 

[i=p/u]

Maybe only 60A on carrier .....

 

[Andy78]

Yes, but I'm talking about quite small exposed parts, the question is whether they should be defined as accessible - comparing for example to an unenclosed choc block, a small one you can't touch the screws, make it large enough and perhaps you could.

I would C1 compromised insulation on any live conductor, no matter how small, and a choc block of any size joining a live conductor not in an enclosure would get the same treatment.

 

[telectrix]

Yes, but I'm talking about quite small exposed parts, the question is whether they should be defined as accessible - comparing for example to an unenclosed choc block, a small one you can't touch the screws, make it large enough and perhaps you could.

child with paper clip in sticky paw can access anything < IP4X. so code C1 for any exposed conductor or terminal , no matter how small the access is,