18th edition draft now available for comment

[flameport]

It's working for me now, no idea what the problem was earlier.

 

[333rocky333]

542.1.201, installations to have an earth electrode to supplement any suppliers earthing facility.

I dont have 542.1. 201 in my book, but in the red book 542. 1. 2 is only old TNS systems

 

[John D v2.0]

I don't think it is for RCDs, more to do with limiting touch voltages in the event of a failure of the suppliers earth.

How would that work? With a pfc of >500A there's not much a rod can do about touch voltage, you're relying 100% on your equipotential zone and RCD at that point!
Edit: saw that the reason as you say is there in the document. However I still don't understand my question s answer! Anyone?

 

[flameport]

Cables now have to be adequately supported against premature collapse everywhere, not just escape routes.

which effectively means plastic cable clips can't be used any more, plastic trunking can only be used if the cables within have additional metal clips, and manufacturers of round plastic conduit might as well stop making it.

However, manufacturers of earth rods and covers are in for a bonanza of additional sales.

 

[flameport]

Things that should have been deleted but were not:

BS3036 semi enclosed rewirable fuses
Ring final circuits
Socket outlets in bathrooms must be 3m from the bath.

 

[John D v2.0]

At risk of starting the ring final debate, what's the objection? I know they're an anomaly but if I want a 32a circuit it's nice to work with 2.5 cable.
And who has a 3m bathroom?

 

[flameport]

And who has a 3m bathroom?

Nobody. The point is that socket outlets should be permitted within a more sensible distance, such as 1m.
Most other countries allow this and have done for decades.
In the UK, it's no sockets so people either attempt to connect inappropriate things into the shaver socket (toothbrush chargers etc.), or use an extension lead from another room for their hairdryer or whatever.

 

[EFLImpudence]

I presume in 542.1.201 where it says:

It should be 542.2.2.

Good start.

 

[John D v2.0]

I presume in 542.1.201 where it says:

View attachment 120508

It should be 542.2.2.

Good start.

Well that'll just a typo. I'm more interested in what they expect a rod to do...

How would that work? With a pfc of >500A there's not much a rod can do about touch voltage, you're relying 100% on your equipotential zone and RCD at that point!

 

[aptsys]

At risk of starting the ring final debate, what's the objection? I know they're an anomaly but if I want a 32a circuit it's nice to work with 2.5 cable.
And who has a 3m bathroom?

I do... 3m falls next to the toilet - maybe I should put a socket in for charging phones.

 

[John D v2.0]

I do... 3m falls next to the toilet - maybe I should put a socket in for charging phones.

you need a doctor not an electrician

 

[winston1]

so people either attempt to connect inappropriate things into the shaver socket (toothbrush chargers etc.),

What is inappropriate about a toothbrush charger? Many shaver sockets actually have a toothbrush symbol on them.

 

[JohnD]

there was a time when bathroom shaver sockets were designed for intermittent use measured in minutes per day, the isolating transformer only being energised when a plug was inserted.

toothbrush chargers may be plugged in for many hours, or permanently, and it was warned that this could lead to overheating with no "off" period to cool down.

It would be a good idea for modern shaver sockets to be designed to accomodate this usage. Perhaps they have been.

 

[ban-all-sheds]

I have always taken it that if a socket displays a toothbrush symbol then it has been designed to accommodate that use.

I have also always taken it that my MK shaver socket with no such symbol is absolutely fine when a toothbrush charger is plugged in for extended periods.

 

[securespark]

I cannot get access to the draft, are you able to expand on this please?
Cheers.

Sure (paraphrased):

543.3.3.101

No switching device to be inserted in a protective conductor except:

i. As permitted by 543.3.102 (another typo!!)

ii. a multipole linked switching device (MLSD) arranged to disconnect and connect the protective conductor circuit at substantially the same time as the live conductors.

iii. a switching device interlinked with a MLSD such that the protective conductor circuit shall not be interrupted before the live and shall be reestablished not later than the lives.

iv. multiple plug in device which connects E first before lives and disconnects E last.

543.3.3.102

Where an installation is supplied from more than one source of energy, one of which requires a means of earthing independent of the means of earthing of other sources and not more than one means of earthing is applied at any one time, a switching device may be inserted in the connection between the neutral point and the means of earthing.

I feel the way these two have been written is a bit clumsy.