Regulations Myths

[Harry Bloomfield]

But I knew that before 1966 we were permitted lighting without an earth, and now only the pendent part is allowed not to have an earth, but looking at the regulations, Chapter 41 in old 2008 edition, heading Protective earthing, but Chapter 55 was all about Luminaires, so one can understand why people fail to find the regulation.

I think that was introduced, to address the appearance of more and more metallic lighting fittings, plus of course replacement of ordinary lampholders, with fluorescent lighting, often installed without an earth.

 

[JohnW2]

Lots of myths are abound, someone says something, someone else hears it wrong then it gets retold wrongly in their own way and so on.

Indeed - and it's true in most fields, certainly not just 'electrics'. A lot of the things I was taught during my professional education had been believed for decades, but subsequently found to be nonsense, based on nothing!

Nor is it necessarily only 'myths' (i.e. things that are 'wrong' or not actually true) that get perpetuated by the "that's how we've always done it" phenomenon (i.e. following each other like sheep). For example, I never understood how it ever came to be that 1.5 mm² cable was very widely used in domestic lighting circuits, other than "that's wot I were taught and it's how we've always done it". There's nothing actually 'wrong' (apart from wastage of money and resources) in using 1.5 mm², but I struggle to understand how it can ever have been thought to be 'necessary'
[ did it possibly arise in the course of transition from imperial cable sizes? ]

 

[JohnW2]

I think that was introduced, to address the appearance of more and more metallic lighting fittings ...

That may well have been part of the reason.

However, for decades before 1966 there had been plenty of partially metal things being connected to lighting circuits - quite apart from light fittings, there were the notorious light switches with round brass 'fronts' which I, when not much more than a toddler, I could (and sometimes did ) unscrew 'without use of a tool'.

 

[securespark]

When I suggested using 1 milli for lighting at one company I worked for as an apprentice in the 80s they stared at me and said "are you f.....g homophobic slur removed?"

As if it wasn't manly to use 1 milli....n

The local CEF manager in Macc sold so much 1.5 it should have been cheaper, but it never was...

 

[Harry Bloomfield]

Nor is it necessarily only 'myths' (i.e. things that are 'wrong' or not actually true) that get perpetuated by the "that's how we've always done it" phenomenon (i.e. following each other like sheep). For example, I never understood how it ever came to be that 1.5 mm² cable was very widely used in domestic lighting circuits, other than "that's wot I were taught and it's how we've always done it". There's nothing actually 'wrong' (apart from wastage of money and resources) in using 1.5 mm², but I struggle to understand how it can ever have been thought to be 'necessary'
[ did it possibly arise in the course of transition from imperial cable sizes? ]

Originally, many lighting circuits were wired in 1/044, or 3/029. The translation to 1.5mm probably occurred, because 1.5mm was more robust, and provided a better fit into terminals, rather than any need for the extra current capacity. The difference in cost between 1.0mm and 1.5mm, was minimal.

 

[JohnW2]

When I suggested using 1 milli for lighting at one company I worked for as an apprentice in the 80s they stared at me and said "are you f.....g homophobic slur removed?" .... As if it wasn't manly to use 1 milli....n

Quite so

 

[EFLImpudence]

But I knew that before 1966 we were permitted lighting without an earth,

The only reason it is not permitted today if not needed is just in case it is needed in the future.

Also, nothing in the electrical regulations on socket heights, that's building regs,

And even there it is only a recommendation.

 

[securespark]

The difference in cost between 1.0mm and 1.5mm, was minimal.

Not at CEF, it wasn't!

 

[JohnW2]

Originally, many lighting circuits were wired in 1/044, or 3/029. The translation to 1.5mm probably occurred, because 1.5mm was more robust, and provided a better fit into terminals, rather than any need for the extra current capacity.

As I said, I wondered if that might have been the explanation.

The difference in cost between 1.0mm and 1.5mm, was minimal.

Well, maybe the differences in cost weren't passed-users and/or copper was very cheap in those days - after all 1.5 mm² has 50% more copper than 1.0 mm²!

 

[securespark]

Regarding socket heights, there is general stuff in the regs about selection and erection to avoid damage.

And of course, there is part M and BS 8300 for disabled folk.

 

[EFLImpudence]

Nevertheless...

 

[Risteard]

As I said, I wondered if that might have been the explanation.

Well, maybe the differences in cost weren't passed-users and/or copper was very cheap in those days - after all 1.5 mm² has 50% more copper than 1.0 mm²!

Except on the cpc for T&E.

 

[EFLImpudence]

I missed it had already been said.

 

[ericmark]

Most boilers seem to have a FCU not a plug and socket, so hard to plug into a generator in an emergency without the use of a widow maker, also need a locking off device designed for that make of FCU, to lock the switch off. (The fuse only supplies line, so neutral still connected so technically not isolated) Where if using a 13 amp plug, where these

are universal for all 13 amp plugs.

The only reason I can think of, was some regulations back, we did not need to protect FCU with an RCD, however buried cables in wall rule has in the main change that.

I have asked on Plumbing section it does say in some boiler manuals to use a FCU, likely written before the rules on RCD's changed. So other than that's the way we have always done it, why would one use a FCU to supply a boiler? As to being able to unplug locking sockets would stop that

so why are FCU used to supply boilers? These

will allow us to have central heating even with a power cut, not sure if 600 watt is enough, but since the use of FCU encourages the use of the widow maker, should a FCU be given a code 2 in an EICR!

 

[JohnW2]

Except on the cpc for T&E.

OK. I admittedly overlooked that, so it's 33.3% more copper - but that's still pretty significant.