Wiring colours

[Adam W]

I can appreciate the predicament having been in a similar situation myself - a 'budget' outfit I was working for thought they could save a few pennies by wiring 2 3 phase air conditioners using just brown and green/yellow wire instead of buying 5 different colours.
Sure enough one of the units was connected up incorrectly, causing £200 worth of damage.

It's really easy to say "get a job with a decent company" but finding one at the moment is a different matter.

 

[Davey101]

I can appreciate the predicament having been in a similar situation myself - a 'budget' outfit I was working for thought they could save a few pennies by wiring 2 3 phase air conditioners using just brown and green/yellow wire instead of buying 5 different colours.
Sure enough one of the units was connected up incorrectly, causing £200 worth of damage.

It's really easy to say "get a job with a decent company" but finding one at the moment is a different matter.

3 different colours?
Nothing wrong with wiring all 3 phases in brown (sleeved/taped correctly), its just easier to wire it with Br,Bl,Gr.
Gotta say, in nearly 20 years, I've never seen anyone use the wrong colours for live and neutral

 

[jase]

when wiring emergency lighting then would you use 3 core and earth, br, bl gry, and sleeve the grey as neutral?

 

[Adam W]

3 different colours?
Nothing wrong with wiring all 3 phases in brown (sleeved/taped correctly), its just easier to wire it with Br,Bl,Gr.
Gotta say, in nearly 20 years, I've never seen anyone use the wrong colours for live and neutral

Ideally 5 different colours should be used to avoid confusion. I assume what must have happened in this situation was the HVAC guys shortened the cables, cutting the identification off the ends.

Blue is used for switched live all the time, which is fine if it's correctly identified as per BRB. I would say the problem with using brown (sleeved with blue) singles for neutral is it's just needlessly ambiguous - not strictly a contravention, just poor practice.

 

[Davey101]

Ideally 5 different colours should be used to avoid confusion. I assume what must have happened in this situation was the HVAC guys shortened the cables, cutting the identification off the ends.

Blue is used for switched live all the time, which is fine if it's correctly identified as per BRB. I would say the problem with using brown (sleeved with blue) singles for neutral is it's just needlessly ambiguous - not strictly a contravention, just poor practice.

Blue is only used as a switch wire (live) in a muticore cable. You can use whatever colours you want in a multicore, its totally different in singles. You CAN use the 'wrong' colours in singles, but they must be sleeved along their entire length (thus making them the right colours), anything less IS against regs (and very, very rough).

Brown is live, you dont have to mark the ends in black or grey, you can use L1,L2, L3.
For whats it worth, I'd use 3 different colours given the choice, but there is nothing wrong at all with using 3 browns.

 

[Adam W]

anything less IS against regs...

That seems to be implied, and 514.3.2 says it is preferable (relating to cores of a cable), but I can't find a specific reg which states singles must be identified throughout their length.

 

[Davey101]

I have read somewhere that cables must be identified along their length, i.e. not just at the ends, I'm fairly sure that it must have been in the regs, I'm sure its in there somewhere.

 

[Risteard]

I have read somewhere that cables must be identified along their length, i.e. not just at the ends, I'm fairly sure that it must have been in the regs, I'm sure its in there somewhere.

No. The Regulations state "preferably throughout their length". The south of Ireland requires that they are identified throughout their length so perhaps that's what you read somewhere.

 

[andekoch]

I did a PIR the other day where the 2 way switch had been wired in 3 core flex (ie brown, blue and green/ yellow) and the G/Y was used as one of the lives.

Called the NIC and their comment was it was ok as long as sleved Brown at both ends, with the qualifier that being flex the wire was insulated along its whole length (as opposed to the bare earth in a T&E cable) and the house had RCD protection.
Also in this case the cable could not be removed without major disruption and rework.

Made a big note on the PIR and stuck a lable on the CU to warn future electricians.

 

[Davey101]

No. The Regulations state "preferably throughout their length". The south of Ireland requires that they are identified throughout their length so perhaps that's what you read somewhere.

Definatley not had anything to do with Irish electricity, so I must have been refering to 'preferably'.

 

[Davey101]

I did a PIR the other day where the 2 way switch had been wired in 3 core flex (ie brown, blue and green/ yellow) and the G/Y was used as one of the lives.

Called the NIC and their comment was it was ok as long as sleved Brown at both ends, with the qualifier that being flex the wire was insulated along its whole length (as opposed to the bare earth in a T&E cable) and the house had RCD protection.
Also in this case the cable could not be removed without major disruption and rework.

Made a big note on the PIR and stuck a lable on the CU to warn future electricians.

Why did the house have to have RCD protection because a conductor is sleeved a different colour?