Amendment 4 (2026) to BS 7671:2018 IET Wiring Regulations.

Sparkingchip said:

So, it is time to start planning ahead.

My first question is it a new book? There seems to be a lot of additional information and possibly changes as well.

There is no official information at the moment. However, lots of changes usually means the best approach is an updated 'book'.

Sparkingchip said:

There is a third question, which is when the 19th Edition is being published, which presumably will require new books and an exam, but I assume that won’t be published for at least two years?

We don't know the answer to that question yet. 

Thank you.

gkenyon said:

There is no official information at the moment. However, lots of changes usually means the best approach is an updated 'book'.

Like a toddler weaned from its dummy, it took a long time, but I am now a convert to the electronic version. My brown book is battered and abused but I rarely have need of it now. 
However, whether the lumberjack squads will be out felling forests for the next iteration remains to be seen. I imagine a large part of hard copy demand is driven by the current exam format so unless a new greener method of assessment can be devised, I guess axes will continue to be sharpened.

lyledunn said:

I guess axes will continue to be sharpened

Unless we break with tradition and instead of a big red book, we go for a Green one. 

gkenyon said:

There is no official information at the moment. However, lots of changes usually means the best approach is an updated 'book'.

I would perhaps also add, that the DPC for the next Amendment was "the whole book"

With the information available here: https://electrical.theiet.org/bs-7671/updates-to-18th-edition/ well, I guess that's all the publicly-available information, so our industry rumour mill can eat all this information and provide an answer.

OlympusMons said:

Unless we break with tradition

Which 'tradition' ?

If you look back carefully, we'd first have to ignore 18th Edition, and prior to that you might be able to discern a 'pattern' for 17th Ed against 16th Ed against 15th Ed.

BUT

Even that is 'broken' for those who want to be very pedantic, because the 16th Ed of the IEE Wiring Regulations, published in 1991, was published with both a red cover (paperback) and a dark blue cover (hard back)

When you write down the cover colours and try to order them, there is no pattern at all really. Red appears as a cover colour for the first version in each "edition" most often ... but it's not a "rule" ... and prior to 8th Edition, there is no cover; as far as I know, they were all white "pamphlets".

gkenyon said:

When you write down the cover colours and try to order them, there is no pattern at all really.

This is certainly possible to do, if you have prior Editions, or can find pictures of them on-line.

The information for cover colours on page 12 of BS 7671:2018+A2:2022 only starts at 15th Edition, but it doesn't mean coloured covers were not used earlier ... coloured covers were in fact used from the 8th Edition onwards.

Will BS7671 Amendment 4 address if a domestic dwelling smoke alarm IC (Inter Connect) conductor needs to be colour/identified and which colour should be used?

Reasoning is that BROWN is for 230v nominal AC LIVE and as most/some people know the IC (Inter Connect) is 9V to 12V DC (Direct Current) during alarm operation or heartbeats. Thus maybe the colour for the IC should be RED. That being said that would be under normal operating conditions. Under fault conditions it is POSSIBLE that the IC may become live at 230V AC.

As a side note. In the UK, standard DC cable colour codes are as follows: Red is typically used for the positive (+) wire, and Black for the negative (-) wire thus RED for the IC makes sense to me.

If you identify it as RED and it should be identified/labelled as something in my opinion then at the CU (Consumer Unit) put a note to say RED at smoke/heat alarms is the IC. (Helps the next person)

Caveat time

What if we have old cable in place, Red, yellow, blue? We would now have 2 reds.

What if we have old cable in place, Red, Black, Green/Yellow or bare? We would now have 2 reds.

Sergio Fernandez said:

Will BS7671 Amendment 4 address if a domestic dwelling smoke alarm IC (Inter Connect) conductor needs to be colour/identified and which colour should be used?

Why would it? It's a conductor of a system for which BS 7671 refers out to BS 5839 series in a number of places, including 110.1.3 (v). For example, BS 7671 tells you the identification for PE and FE conductors ... but it won't tell you whether the fire alarm loop earth is PE or FE: that's addressed by BS 5839-1:2025, see Clause 28.2. Similarly, BS 5839-6 already contains a provision that could be tightened up.

In a similar manner, BS 7671 won't tell you which pin is connected to which core in an RJ45 plug or socket-outlet, or that different colours to Table 51 might be used in Machinery to BS EN 60204-1.

Sergio Fernandez said:

Reasoning is that BROWN is for 230v nominal AC LIVE and as most/some people know the IC (Inter Connect) is 9V to 12V DC (Direct Current) during alarm operation or heartbeats. Thus maybe the colour for the IC should be RED. That being said that would be under normal operating conditions. Under fault conditions it is POSSIBLE that the IC may become live at 230V AC.

BUt it's a control/monitoring link (regardless of it being ELV, FELV or LV? BS 7671 permits a number of options at the bottom of Table 51. However, as above, you are referred to in Regulation 110.1.3 to another series of standards to decide what the function is and what the colour identification should be. See below - this is already covered in BS 5839-6.

Sergio Fernandez said:

As a side note. In the UK, standard DC cable colour codes are as follows: Red is typically used for the positive (+) wire, and Black for the negative (-) wire thus RED for the IC makes sense to me.

No, for a DC power circuit, they are Red for L+, White for L-, and this has been printed as such in Table 51 since BS 7671:2018+A2:2022. 

For AC or DC controls, see the bottom of Table 51 (BS 5839-6 already implies this by saying not the same colour as power conductors, see below)

Sergio Fernandez said:

Caveat time

What if we have old cable in place, Red, yellow, blue? We would now have 2 reds.

What if we have old cable in place, Red, Black, Green/Yellow or bare? We would now have 2 reds.

This advice should be provided in BS 5839-6, which specifies the interlink.

BS 5839-6 already makes the following provision (my highlight):

16.4 Recommendations for wiring in Grade D systems
The following recommendations should be met.

a) Cables used for the mains supply to smoke alarms and any heat alarms, and any interconnecting wiring between all smoke/heat alarms, should be suitable for domestic mains wiring.
b) Conductors used for interconnection of smoke/heat alarms should be readily distinguishable from those supplying power (e.g. by colour coding).
c) Wiring systems of any circuits in Grade D systems should conform to the general requirements of BS 7671.

Will BS7671 Amendment 4 address if a domestic dwelling smoke alarm IC (Inter Connect) conductor needs to be colour/identified and which colour should be used?

I thought it already did ... as it's a control line, bottom bit of table 51 applies - so you can choose what you like from Black, Brown, Red, Orange, Yellow, Green, Violet, Grey, White, Pink or Turquoise. I usually find it it convenient to reserve brown/blue for the main L & N - so whatever's left in the 3-core cable can usually be left unsleeved as a control wire.

e.g. Brown/Black/Grey - brown is L, Grey is oversleeved blue as N, so Black is IC. For older installation, Red would be L, blue oversleeved black would be N (by the old convention) so yellow is IC.

   - Andy.

AJJewsbury said:

I thought it already did ... as it's a control line, bottom bit of table 51 applies - so you can choose what you like from Black, Brown, Red, Orange, Yellow, Green, Violet, Grey, White, Pink or Turquoise.

Not quite ... with Clause 16.4 of BS 5839-6, this rules out the use of colours supplying power.

The only argument is whether you take that to be 'colours supplying power' in the entire electrical installation, (which could be BN, BK, GY, BU, RD and WH) or just in the fire alarm installation (that is typically BN and BU in installations with Grade D systems with interlink).

AJJewsbury said:

I thought it already did ... as it's a control line, bottom bit of table 51 applies - so you can choose what you like from Black, Brown, Red, Orange, Yellow, Green, Violet, Grey, White, Pink or Turquoise.

Not quite ... with Clause 16.4 of BS 5839-6, this rules out the use of colours supplying power.

The only argument is whether you take that to be 'colours supplying power' in the entire electrical installation, (which could be BN, BK, GY, BU, RD and WH) or just in the fire alarm installation (that is typically BN and BU in installations with Grade D systems with interlink).