New yellow book

[mac42]

Do I need this for minor electrical works? I watched an excellent video by John Ward on youtube where he goes through the changes, and it seems the main issue for me is about margins which I'm unlikely to be anywhere near. The thing that I'm unsure about is whether the Minor Works Certificate has changed.

Can anyone advise?

thanks,
S.

 

[PrenticeBoyofDerry]

The form in it's self has changed little, other than a request for a risk assessment to be attached if applicable.
Obviously the regulation need to be complied to, and the fact that the form should be authorised by a suitable electrically skilled person, with respect to design, construction and inspection/test.

 

[JohnW2]

Do I need this for minor electrical works? I watched an excellent video by John Ward on youtube where he goes through the changes, and it seems the main issue for me is about margins which I'm unlikely to be anywhere near.

Those are, indeed, amongst the most obvious changes. All of the 'maximum Zs' figures (to achieve required disconnection times) have reduced by 5% as compared with the figures in the 'Green' book (Amendment 1).

Probably the most important other change is the requirement that (as from 1st Jan 2016) all new CUs etc., should be constructed of (or enclosed in an enclosure constructed of) 'non-combustible' material - although no-one seems really sure what that means (beyond the fact that metal is clearly 'non-combustible').

The thing that I'm unsure about is whether the Minor Works Certificate has changed.

As PBoD has said, there are no material changes in the MWC form.

Kind Regards, John

 

[ban-all-sheds]

Do I need this?

It's advisable.

 

[PBC_1966]

Probably the most important other change is the requirement that (as from 1st Jan 2016) all new CUs etc., should be constructed of (or enclosed in an enclosure constructed of) 'non-combustible' material - although no-one seems really sure what that means (beyond the fact that metal is clearly 'non-combustible').

I wonder if this change would ever have come about had the design of plastic units not been so cheapened over the years that many of them are now nothing more than flimsy containers to keep fingers from touching live parts rather than offering any real physical strength to the unit as a whole. Given the current designs of plastic units, it might be as well to see the back of them.

 

[ban-all-sheds]

And inside the flimsiness, terminals of poor design.

 

[ban-all-sheds]

metal is clearly 'non-combustible'

If you stump up for the hire of a thermal lance, and a man who knows how to use it, we'll come round and show you metal burning.

 

[flameport]

The reduced maximum Zs should not be an issue at all, as most circuits should not be anywhere near the old or new maximums.
For domestic type installations, it's actually rather difficult to get anywhere near the limits, as the circuit lengths would have to be ridiculously long.

 

[JohnW2]

The reduced maximum Zs should not be an issue at all, as most circuits should not be anywhere near the old or new maximums. For domestic type installations, it's actually rather difficult to get anywhere near the limits, as the circuit lengths would have to be ridiculously long.

Agreed, but I have to say that it never made much sense to me that the regulations' 'maxima' would only achieve the required disconnection times provided one's supply voltage was not less than nominal (i.e. 230V).

They've now almost corrected that anomaly. I understand that it is some 'Euro-compliance' which has resulted in the fact that there theoretically could still be a few UK consumers for whom the regs' 'maxima' would not achieve the specified disconnection times - i.e. if their supply voltage fell to between 230V-6% (i.e. 216.2V) and 230V-5% (i.e. 218.5V) - but I suspect that would be extremely unusual.

Kind Regards, John

 

[PBC_1966]

And inside the flimsiness, terminals of poor design.

Yes - How come the terminals on the main switch of so many now seem to suffer from tails loosening up? That was never a problem with units such as the old MEM or Wylex Standard range.

The cheapening-up of products isn't unique to the U.K., of course. All distribution panels here are metal, but certainly the "insides" of some of them aren't what they used to be. I was looking for a new sub-panel to install here onto which I'll gradually be transferring circuits as I rewire sections of the house, and had narrowed the choice down to the Square D QO range or Cutler Hammer CH range (now owned by Eaton), two which have been highly regarded for many years. But Square D has now transferred production of the QO series to Mexico and cheapened the internals by using plastic in many places which were formerly steel, such as the support bar that the breakers clip onto. It just feels so much more flimsy than the older models. The CH is still much more rugged with the feeling that it's built "up to a standard" rather than "down to a price." And, at least for the moment, is still made in the U.S.A. So CH it is. Although to be blunt, even the cheapened QO range here still beats the overall flimsy construction of many U.K. units now.

 

[JohnW2]

And inside the flimsiness, terminals of poor design.

Yes - How come the terminals on the main switch of so many now seem to suffer from tails loosening up? That was never a problem with units such as the old MEM or Wylex Standard range.

One of the reasons, of course, is that those old bits of exceptional engineering had (certainly the Wylex Standard, I can't remember about MEM) dual screws for all connections. The concept of redundancy ('belts and braces') has stood the test of time, even if it's been forgotten in so many areas!

Kind Regards, John

 

[PBC_1966]

I certainly recall that at least some of the MEM units had dual terminal screws. The Wylex Standard range was beautifully engineered in so many ways.

 

[JohnW2]

I certainly recall that at least some of the MEM units had dual terminal screws. The Wylex Standard range was beautifully engineered in so many ways.

It certainly was - those were the days!

Kind Regards, John

 

[ban-all-sheds]

Do I need this for minor electrical works?

If you do buy a copy, AFAIK TLC are still the cheapest.

 

[Adam_151]

certainly the "insides" of some of them aren't what they used to be.

40 Years ago you could have had a federal stab-lok

But seriously... why do the insides of all US boards look similar to the boards we had here in the 70s with plenty of un-shrouded parts inside? I would have throught that in a country where people sue each other over the drop at a hat that there would be some pressure to improve in a similar way to the boards over here?

Square D QO range

Those look very similar to the Square D QO-X range which are sometimes found on installations 30-35 years old here. They are often unsuitable due to being type 4 and the max zs not being met. Do USA breakers have any type of type classification on the magnetic trip... or is it one type fits all?