18th edition draft now available for comment

[winston1]

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.

I've never had such a problem. I have had rechargeable shavers since the early 70's and always recharged them in a shaver socket.

 

[ban-all-sheds]

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

So they are not totally breaking with tradition then.

 

[JohnD]

I've never had such a problem. I have had rechargeable shavers since the early 70's and always recharged them in a shaver socket.

And what was the temperature of the 1970's transformer after 12 hours charging?

 

[ban-all-sheds]

If it's the same as my '00s one it was sufficient to raise the temperature of the faceplate to a totally unconcerning very slightly warmer than the surroundings.

 

[winston1]

And what was the temperature of the 1970's transformer after 12 hours charging?

Dunno, but the faceplate was barely warm.

 

[securespark]

Just found this in the current regs:

542.2.7 An earth electrode shall not consist of a metal object immersed in water.

A paperclip in a saucer of water?

 

[securespark]

Re 542.1.201, this is one of the comments in response:

If in an existing installation an earth electrode is installed in accordance with the requirements of 542.1.201, a potential danger could be introduced by

• Creating a low resistance path to the property with an electrode installed that can be shared by several properties in the event of a lost Neutral dependant on the supply configuration.
• The installation of the low resistance path would potentially mask a lost supply fault, which could be left in service undetected.
• Any person working on or testing and inspecting an installation with an electrode can be subject to additional risk, particularly when disconnecting the earthing conductor.

Also achieving the values required for touch voltage are likely not to be met, and it is likely that an electrode cannot practicably be installed, e.g. space restrictions, property types etc.

 

[John D v2.0]

Also achieving the values required for touch voltage are likely not to be met

Yes that's exactly what I was wondering too!

 

[EFLImpudence]

When are these (25,000,000?) electrodes to be fitted?


There shall be an earth electrode and it came to pass that there was one.

Do we have to wait for yet another guide to be published informing us of (someone's opinion of) what work may be done without compulsory fitting of said electrode and what may not?

Thou shalt not change light switches if the earthing arrangements are not to current requirements - or

Will there be a law demanding that the householder shall have one fitted before the 19th edition - due in 2020?

 

[winston1]

When are these (25,000,000?) electrodes to be fitted?


There shall be an earth electrode and it came to pass that there was one.

Do we have to wait for yet another guide to be published informing us of (someone's opinion of) what work may be done without compulsory fitting of said electrode and what may not?

Thou shalt not change light switches if the earthing arrangements are not to current requirements - or

Will there be a law demanding that the householder shall have one fitted before the 19th edition - due in 2020?

Regulations are NOT retrospective, so no need to fit one or 25,000,000.

 

[EFLImpudence]

 

[333rocky333]

I presume in 542.1.201 where it says:

View attachment 120508

It should be 542.2.2.

Good start.

Efli what does 542.1.201 actually say please

 

[securespark]

132.16?

 

[flameport]

a potential danger could be introduced by

• Creating a low resistance path to the property with an electrode installed that can be shared by several properties in the event of a lost Neutral dependant on the supply configuration.
• The installation of the low resistance path would potentially mask a lost supply fault, which could be left in service undetected.
• Any person working on or testing and inspecting an installation with an electrode can be subject to additional risk, particularly when disconnecting the earthing conduct

Those are all equally valid with bonding to metallic pipes such as gas and water, and no one has complained about that.

The reason for these electrodes is probably because most water and gas services are now plastic, and therefore no bonding is installed.

 

[EFLImpudence]

Efli what does 542.1.201 actually say please