BS7671 Amendment 4. Sidebar markers

I have the silver plus subscription and it does not have them on the orange book,the brown book does.

The orange book also scrolls differently.

Newfutile said:

I have the silver plus subscription and it does not have them on the orange book,the brown book does.

The orange book also scrolls differently.

I understand the providers are aware of the issue with respect to the sidebar. In an earlier post, I was a little too quick off the mark to criticise the scroll. Perhaps that was premature and churlish. As I have trawled through the updates, the format is becoming more friendly so I am holding my tongue for the moment!

Hi all,
I've spoken to our Digital team and they've said the following:

"We are aware of this issue and are in the process of determining the best way to resolve it. BS 7671 AMD 4 was uploaded to VitalSource in the ePub3 file format to align with digital accessibility rules that came into effect last year. Whilst we try to resolve this issue, we have uploaded another copy of BS 7671 AMD 4 that matches exactly the printed edition but lacks a lot of the accessibility features currently required. You will be able to access this copy by updating your VitalSource library."

I hope that helps.

I now have 2 versions in my library, a pdf an an epub. The pdf has the book style page scrolling (better IMO) whereas the epub has vertical scrolling. The pdf version also has the side-bar mark-ups. Both are missing much of the hyperlinking that was present in the AMD3 book.

I think I'll wait a couple of weeks before re-doing all my bookmarks, highlights etc 

I wonder what would happen if I repeatedly took my assessor to jobs that had been rushed to get them ready for an assessment date and they were sub-standard, had  mistakes and errors that needed corrections and did not work as intended.  Oh and cost a shed load of money .

Gary

I wouldn't feel too left out if I were you ... even in the printed version the side bars seem not to quite have the value they should have.

Many show only stylistic differences (e.g. "r.m.s." changes to "RMS") while others seem to appear where I can see no changes at all.

Most worrying there seem to be some small but significant changes (e.g. > changing to ≤ in A722,3) which aren't indicated at all (in that case I suspect it's just a correction of an earlier error, but it's still a change from the previous published version as far as I can see).

   - Andy.

AJJewsbury said:

Most worrying there seem to be some small but significant changes (e.g. > changing to ≤ in A722,3)

That must be an error.

Chris Pearson said:

That must be an error.

This is a background for the change:

Above is a clip from BS 7671:2018+A2:2022. NOTE 1 is intending to tell us that there are two conditions where the minimum value of R_{A ev} should be taken as 200 Ω:

(a) Where the formula preceding the NOTE leads to a value of resistance exceeding 200 Ω; and
(b) Where the formula preceding the NOTE gives a negative or invalid (division by zero) value of resistance.

The formula will give a negative value of resistance where I_mU₀C_max ≤ 70 (I_L1+I_L2+I_L3), i.e. for very small neutral currents. Rearranging this inequality, we get:

Which is clearly not was was printed in BS 7671:2018+A2:2022, and hence there was in error here (as above).

AJJewsbury said:

Most worrying there seem to be some small but significant changes (e.g. > changing to ≤ in A722,3) which aren't indicated at all (in that case I suspect it's just a correction of an earlier error, but it's still a change from the previous published version as far as I can see).

Yes, I can see this in my printed version, and the version on VitalSource that's not EPUB 3 format.

AJJewsbury said:

Many show only stylistic differences (e.g. "r.m.s." changes to "RMS") while others seem to appear where I can see no changes at all.

Style changes (such as moving to all caps, or changing list formats) have not changed the actual of the requirement, and therefore were not considered a 'change' - it's just formatting.

Graham, thank you - that is v. helpful.

gkenyon said:

minimum value of R_{A ev} should be taken as 200 Ω

Surely that is maximum, not minimum? i.e. even if the equation allows R_{A ev} to be > 200 Ω, it should never be greater than this value.

gkenyon said:

The formula will give a negative value of resistance where I_mU₀C_max ≤ 70 (I_L1+I_L2+I_L3)

Or ∞ when I_mU₀C_max = 70 (I_L1+I_L2+I_L3). That was what was bothering me.

Looking back to the blue book, it explained in the note to A722.3 that where the equation was invalid, condition (i) in 722.411.4.1 applied, but that was deleted in the brown book.