I have bought some three core and earth cable for connecting my central heating system thermostats..
The cable colours are brown black and grey.
I want to connect two thermostats.
Stat1 requires live, neutral and load.
Stat2 has live, load when below desired temp, and load when above desired temp.
Is there a convention as to what colour wire should be used in each of these cases?
Are you competent? Anyone who is competent should know (or have ready access to) such information. Is the rest of your house wired in the old red and black colours? If so you have some important issues to address.
Download this leaflet:
Peter
Which tells you absolutely nothing about what the OP wants to know. He has purchased cable designed primarily for two way switches and wants to use this cable for two different types of thermostat. This cable uses the three phase colour convention (as all conductors may be live and having a neutral colour might be hazardous - previous cable used blue and yellow). The OP gave no indication he was unaware of the new colour codes for single and three phase. The leaflet only refers to three phase wiring and does not offer any convention for use in his case (which is why I presume he was asking). Nor indeed may there be any such convention! For the second thermostat I would use the brown for live and the grey and black in any order for the loads. For the first I would probably use brown for live and black for neutral, reserving grey for the load. I would mark the returning loads with red or brown sleeve/tape at the load end.
Not really - but most would make the always live brown. I'd use black for the neutral - since that used to be the colour. As regards the high/low one your choice.
Bollocks.
Please sort out your facts before posting criticism.
There are no implications for this task.
W*nker. Whatever happened to trying to be helpful (and don't give me that "I *am* being helpful"). It's not f*cking rocket science we're talking about here.
Sadly, the "DIY" element of this groups seems to be being forgotten by a number if folk here.
Tim
I believe The IEE recommend using grey for neutral in this case, and also in the case when using a three-core SWA for a single phase supply and one core for earth. Reasoning being to get away from the idea that black = neutral. There is a thread about it somewhere on the IEE forums.
DIY does not mean that Part P should be ignored. Also, implications of selling a house in the future can become a serious issue if regulations were not followed and the buyer has a detailed inspection carried out. Being "Helpful" may also mean - "I suggest you do more research before getting into a mess." The solution may be beyond a few hints and tips on the newsgroup. (eg. mixed wiring standards) Thanks
If you are so clever, what are the issues?
MBQ
RED BROWN YELLOW BLACK BLUE GREY
Yup, tis the new standard.
You can see the recommended mapping of old to new colours here:
Well in both these cases you in effect have a permanent live, a switched live, and a neutral. You may find with modern battery operated stats that the neutral terminal is just provided for "parking" an existing neutral connection.
The correct way to use the colours in this case is to use the brown as live, the black as switched live, and the grey as the neutral.
You should also place a brown sleeve on the black wire ends to indicate it is being used as a single phase live, and a blue sleeve on the ends of the grey to indicate its being used as a neutral.
If the installation does not already have it, and this is the first ime new colours have been used then you should affix a sticker on or near the CU that says
"CAUTION
This installation has wiring colours to two versions of BS7671.
Great care should be taken before undertaking extension, alteration or repair that all conductors are correctly identified. "
(see wiki for more details)
He could become so very quickly if someone took the time to post the answer to his question.
That is correct. Of course so far as the regs (BS 7671) are concerned the only relevant colours are brown for line and blue for neutral, and sleeving must be added where necessary. So we have:
Core Sleeving Use
----- -------- -------------------- Brown [none] Line feed Black Brown Switched line (load) Grey Blue Neutral Bare Grn/ylw CPC (earth)
'Line' being the new term for what used to be called 'phase' or (wrongly) 'live'.
One other thing is necessary to complete the job here and that's to apply a 'new colours label' at the consumer unit - e.g. one of these
It does. It's a rubbish law and of no benefit to anyone.
As does any work carried out by anyone - pro or amateur. If a 'detailed inspection' of anything around the house comes up with problems the buyer won't be in the least interested in who actually did the work.
FFS. With things like thermostat and boiler wiring where multicore cable is involved there are *no* absolute standards. Different makers of such things use different colours.
What's Part P got to do with it? The OP might be wiring up his non-domestic workshop, mobile home, or cottage in Scotland, none of which are covered by Part Pee.
Owain
I didn't feel suffiently expert to give advice - only a warning. However, John Rumm has provided detailed good advice.
However, I know enough to view your comments about boilers and thermostats to be very misleading. Whatever the device it still has 'lives', 'switched lives', neutrals' and 'CPC' which should all follow the correct colour conventions - or where will we be? (Spain?).
Page 1 is single phase! and shows old v new colours
To be fair, in this circumstance which colours you use makes little difference as long as you sleeve things accordingly. Most applications using 3&E in domestic wiring are not going to be able to use the standard colour coding.
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