coding on commercial

[Sb8389]

Hi guys,
Just want some advice on codings for an EICR im doing at a factory.
1-they have wired a radial circuit feeding several sockets in singles using blue singles as a live conductor and black as a neutral.
2-they have 3x ring main mains on 32amp RCBOs type C and all zs values are higher than the permitted zs. With this having RCD protection are you ok to rely on this for fault protection.

Your help is appreciated.

 

[telectrix]

1. C2.

2. C3.

both IMO.

 

[davesparks]

Is this a pre-harmonisation installation?
And is the socket radial connected to L3?
If the answer to both is yes then no code, blue was a phase colour in those days and it used to be ok to wire SP circuits in their relative phase colour

 

[Deleted member 72666]

Is this a pre-harmonisation installation?
And is the socket radial connected to L3?
If the answer to both is yes then no code, blue was a phase colour in those days and it used to be ok to wire SP circuits in their relative phase colour

Seen this a lot especially on lighting split over 3 phases, can be rather confusing when making alterations or additions.

 

[baldsparkies]

If pre-harmonisation there should be a mixed wiring notice.
If not a code 2 from me.
If the notice is in place, no code.

 

[Sb8389]

Cheers guys yea it is on blue phase so i have learned something new today.much appreciated.

 

[Deleted member 9648]

An RCD to bs 61009-1 can be used to comply with disconnection times on a TN system for a final circuit not exceeding 32a. 411.4.9
No code if the measured Zs does not exceed the values in table 41.5.

 

[Sb8389]

Cheers wirepuller,both questions answered.

 

[baldsparkies]

Should have stuck with good old reliable Red Yellow Blue with Black for neutral,
Question wouldn't even need to be asked.
And under poor light conditions much easier to identify than browns blacks and grey's
Ok I know, I'll get off me box !!

 

[davesparks]

If pre-harmonisation there should be a mixed wiring notice.
If not a code 2 from me.
If the notice is in place, no code.

Why would it need a notice if pre harmonisation, the colours are correct! Blue for L3 and black for neutral.

 

[davesparks]

Cheers guys yea it is on blue phase so i have learned something new today.much appreciated.

Are you sure you should be carrying out EICRs if you don't know that a blue cable connected to the blue phase is acceptable?

 

[Sb8389]

I can see where your coming from davesparks but i have been doing EICRs for a while and i like to think i am pretty thorough. I do know that blue is a phase colour obviously but its the first time i have come across using it on a single phase circuit and it does make sense now you have said it,but if im unsure about something id rather ask so i can learn rather than just making a judgement myself and not being sure.

 

[Risteard]

Are you sure you should be carrying out EICRs if you don't know that a blue cable connected to the blue phase is acceptable?

It has been unacceptable under BS 7671 for quite a number of years to wire single phase circuits in phase colours. (Other national standards do still permit this arrangement.)

With black becoming a phase and blue becoming neutral it's certainly conceivable that this arrangement could lead to confusion. Therefore it's up to the inspector to decide whether there is a safety issue, and I doubt it is quite as clear cut as some are making out.

Just because something was permissible when it was installed does not necessarily imply that it is considered safe today.

 

[davesparks]

It has been unacceptable under BS 7671 for quite a number of years to wire single phase circuits in phase colours. (Other national standards do still permit this arrangement.)

With black becoming a phase and blue becoming neutral it's certainly conceivable that this arrangement could lead to confusion. Therefore it's up to the inspector to decide whether there is a safety issue, and I doubt it is quite as clear cut as some are making out.

Just because something was permissible when it was installed does not necessarily imply that it is considered safe today.

Then you might as well fail every installation with RWB and RYB coloured conductors, and all the solid green since there is a reg specifically forbidding the use of green.

 

[baldsparkies]

If anything about this is unsafe, its the ****s that sat around a table deciding to change perfectly acceptable and in my humble opinion far easier to identify RYB colors in the first place.
I can remember most sparks thinking it was ridiculous at the time, but who listens to us !!
We are just the men in the field, going over the trenches when the command is given.

 

[D Skelton]

1. C3 (if wiring is pre harmonisation then no code)
2. No code

 

[Deleted member 9648]

It has been unacceptable under BS 7671 for quite a number of years to wire single phase circuits in phase colours. (Other national standards do still permit this arrangement.)

With black becoming a phase and blue becoming neutral it's certainly conceivable that this arrangement could lead to confusion. Therefore it's up to the inspector to decide whether there is a safety issue, and I doubt it is quite as clear cut as some are making out.

Just because something was permissible when it was installed does not necessarily imply that it is considered safe today.

Had exactly this issue in a school. All the single phase circuits are wired in R/Y/B phase colours. My view is that anyone working on a 230v circuit in a non domestic installation should be competant enough to correctly identify conductors. Only when the incompetant become involved does it go pear shaped. In this particular school I came across a number of minor additions installed by the caretaker....(yes,really!!)...in which he'd wrongly connected blue as N and black as L.
Proves two points.
1. The unbelievable daftness of having the colours blue and black which could be either phase or neutral.
2. Caretakers in school should stick to pushing brooms.

 

[Deleted member 72666]

Caretakers should also take care!

 

[Risteard]

Then you might as well fail every installation with RWB and RYB coloured conductors, and all the solid green since there is a reg specifically forbidding the use of green.

LOL. I'm not sure how you can compare solid green cpcs with the use of blue and black conductors, which as I pointed out might mean phase L3 and neutral in pre-harmonised colours, or alternatively it could mean neutral and phase L2 in harmonised colours. Therefore it certainly could be said to be confusing unless there were alphanumeric markings at the terminations!

 

[davesparks]

LOL. I'm not sure how you can compare solid green cpcs with the use of blue and black conductors, which as I pointed out might mean phase L3 and neutral in pre-harmonised colours, or alternatively it could mean neutral and phase L2 in harmonised colours. Therefore it certainly could be said to be confusing unless there were alphanumeric markings at the terminations!

They both complied with the regulations at the time, they both present no danger to anyone competant to be working on it.