it seems to be open to wild interpretation
Wild is right. A trawl through some of the arguments over this on the IEE forum provides some extreme examples.
You wouldn't think a silly little thing like earth wires in switch boxes being either unsleeved or sleeved in plain green instead of the current green/yellow would be that controversial. Bare was allowed under the 13th edition, and plain green was allowed by the 14th ed. up to the late 1970s, so code 4, right? Code 4 is meant to convey something which complied in the past, does not comply with the current Regs., but is not necessarily unsafe.
Well, I've seen some guys doing a P.I.R. saying that a green earth would be a code 2.
To be honest, an earth sleeved in the former green instead of green/yellow is barely worth mentioning but in my opinion it absolutely, positively does not warrant anything more than code 4.
I wonder if in a few years we'll have reports listing red/black cable as code 2, suggesting that it needs to be changed to brown/blue?
I've even seen a couple of people say that a bare earth should go down as a code 1. Are they serious?
Code 1 is meant for something which is flat-out dangerous and requires immediate attention.
If you start putting down bare earth wires as code 1, what message does that give over genuinely dangerous situations which really warrant that code?
Another example: There was a P.I.R. argument over an old Crabtree C50 distribution panel (common in commercial applications 30-35 years ago). Somebody was arguing that it should go down as code 1 because -- get this -- it has bare busbars
inside the enclosure. Someone else was suggesting code 2, or code 4.
The fact is, even though many new panels are now so insulated inside that removing the outer cover hardly exposes any live terminal, there is absolutely
nothing in the
current Regs. which would be violated by that old Crabtree panel. In fact the C50 range is still available!
So the fact that removing the outer cover exposes live parts doesn't warrant anything, not even a code 4.
