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Thread: Colour codes for wiring BDR91's?

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    Question Colour codes for wiring BDR91's?

    Hi,

    Apologises if this is a silly question, but Google hasnít thrown up an answer. Iím preparing to upgrade to an Evohome solution and was wondering if there are any colour coding standards for wiring the A, B & C connections on a BDR91? I'm assuming Live / Neutral are Brown / Blue.

    Thanks

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    Automated Home Legend top brake's Avatar
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    no colour codes for heating wiring generally/in real life (exception being zone valve color codes an industry standard), installations tend to be done using a variety of solid and flexible conductors, twin/earth and 5 core multicore flex

    The BDR91 wall plate is actually designed for twin/earth solid conductor flat cables

    there are L and N connections (permanent live/neutral)

    and A, B and C (switched input/outputs)

    there are several different wiring diagrams depending on the application and they are in the appendix of the installation manual

    as always if you do not regard yourself 'competent person' then please engage a professional heating engneer
    Last edited by top brake; 23rd March 2015 at 02:13 PM.
    I work for Resideo, posts are personal and my own views.

  3. #3
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    Quote Originally Posted by Muzz View Post
    Hi,

    Apologises if this is a silly question, but Google hasnít thrown up an answer. Iím preparing to upgrade to an Evohome solution and was wondering if there are any colour coding standards for wiring the A, B & C connections on a BDR91? I'm assuming Live / Neutral are Brown / Blue.

    Thanks
    You need to either test the wires or look-up the wiring diagram for what they are currently connected to , to reverse engineer what cable does what. I can tell you, that there was no blue neutral in my set-up. It was grey! And Black which used to be the old colour for neutral (red/black), was switched live. So assume nothing here and test carefully. Or if this has made you nervous, get a professional! You may also need to add your own small wire loops from L to A for example as per the wiring diagrams.

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    One of my pet dislikes, if only colour codes were kept to. Some electricians seem to take the view that if the customer in their mind is not going to see it or interfere with it then why bother following a colour coding. Red, black (or blue) and green or green/yellow are all understood but beyond that we have grey and yellow and sometimes both. As said you need to arm yourself with a proper meter, not a cheap live electricity device, and carefully check what each is and when it is. Don't be surprised to find what you think is an earth wire is not but its a live because the electrician ran out of sufficient multi core cable. It ought to be taped to show it is used as a live but don't bank on it.

    I drew a diagram of my connecting box, all the wires coming into it and their colours and where they go and used a meter to check what they did. Then scanned it in and saved it for further use. Always take care, things ain't always what they seem, just use a meter to check things are not live, even when you think you have switched the power off to the circuit. You get less burns and hair raising experiences that way.

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    All points on here are extremely relative and good that different people of different levels of experience are contributing.

    End of the day there is industry standard wiring diagrams for heating systems but you will find some people do odd and sometimes dangerous things. CPC's (earths) should not be used for anything else than protecting the cable/wiring circuit and no matter what colour the wire is it should be sheaved as a live or neutral conductor or as a CPC if the colours of the wire do not represent the function of the conductor.

    If you are unsure of what you are doing, get a pro.

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    Quote Originally Posted by The EVOHOME Shop View Post
    All points on here are extremely relative and good that different people of different levels of experience are contributing.

    End of the day there is industry standard wiring diagrams for heating systems but you will find some people do odd and sometimes dangerous things. CPC's (earths) should not be used for anything else than protecting the cable/wiring circuit and no matter what colour the wire is it should be sheaved as a live or neutral conductor or as a CPC if the colours of the wire do not represent the function of the conductor.

    If you are unsure of what you are doing, get a pro.
    Thanks for all the advice. Having found the "connection box" (pic attached) I'm hoping a pro didn't do the original 80's install, but I agree with odd / dangerous cabling.

    I've drawn the wiring diagram out twice now to reassure myself on how its cabled (not to any wiring standard I can find). I think my next step is to replace the exposed terminal block with something enclosed featuring cable clamps (probably Honeywell 10 way junction box) following the Honeywell Y plan standard leaving the BDR91's in the box for now :-(

    IMG_20150314_100819.jpg

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    Quote Originally Posted by Muzz View Post
    Thanks for all the advice. Having found the "connection box" (pic attached) I'm hoping a pro didn't do the original 80's install, but I agree with odd / dangerous cabling.

    I've drawn the wiring diagram out twice now to reassure myself on how its cabled (not to any wiring standard I can find). I think my next step is to replace the exposed terminal block with something enclosed featuring cable clamps (probably Honeywell 10 way junction box) following the Honeywell Y plan standard leaving the BDR91's in the box for now :-(
    Almost anything would be better than what you have just discovered, looks horrendous! You might find (with apologies to Rameses and Top Brake) that the ACL Drayton wiring centre is cheaper, certainly it has a bit more room inside, separate bus connections for incoming LNE and lots of knockouts and cable clamps round the sides.

    There is a bit more discussion on colour codes here (though the OP turned out to be rather difficult to help)

    http://www.automatedhome.co.uk/vbull...Evohome-System

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    Quote Originally Posted by sharpener View Post
    Almost anything would be better than what you have just discovered, looks horrendous! You might find (with apologies to Rameses and Top Brake) that the ACL Drayton wiring centre is cheaper, certainly it has a bit more room inside, separate bus connections for incoming LNE and lots of knockouts and cable clamps round the sides.

    There is a bit more discussion on colour codes here (though the OP turned out to be rather difficult to help)

    http://www.automatedhome.co.uk/vbull...Evohome-System
    Worth checking out the Honeywell 10 way junction box again as it was redesigned a few years ago for compliance with latest 17th edition Wiring Regs, bigger size, multiple cable clamps, bigger terminals for L N E
    I work for Resideo, posts are personal and my own views.

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    Quote Originally Posted by sharpener View Post
    Almost anything would be better than what you have just discovered, looks horrendous! You might find (with apologies to Rameses and Top Brake) that the ACL Drayton wiring centre is cheaper, certainly it has a bit more room inside, separate bus connections for incoming LNE and lots of knockouts and cable clamps round the sides.

    There is a bit more discussion on colour codes here (though the OP turned out to be rather difficult to help)

    http://www.automatedhome.co.uk/vbull...Evohome-System

    To be honest, it looks very similar to mine! Mine is just a 9 gang terminal block stuck in a white junction housing with no cable reliefs at all...just a white box with a terminal block inside! The wiring does not match any of the specified s-plan or y-plan terminal ordering...and its a house built in 2006. Fortunately I was able to reverse engineer what everything was to add the Hot Water kit in.

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