18th 544.1.2

AlanE · 20 Oct 2018

333rocky333 said:
Is that what ALAN posted, surely thats like shooting hisself in the foot!

Disagree really.

Sorry meant to include this also:

Also from OSG definitions
Extraneous-conductive-part. A conductive part liable to introduce a potential, generally Earth potential, and not forming part of the electrical installation.

I take that to refer that Extraneous-conductive-part is a conductive part that is ouside of the electrical installation, eg a pipe that may, or may not enter from the outside which may produce a potential difference between the electrical Main terminal and that metal pipe. It says that is generally to ground but it does not say the PD might come from elsewhere.

OK I agree heating radiators was pushing it a bit!

ban-all-sheds · 20 Oct 2018

333rocky333 said:
So how do you explain the 16th reg that i assume Alan is referring to which basically says where there IS an Insulating section at the point of entry then bond within 600mm of the Meter outlet union if internal, surely they realise that it is NOT an Extraneous part and require that bond for some other reason.

Which reg #?

SUNRAY · 20 Oct 2018

Well as far as I'm concerned this has been so confusing and interpreted in many different ways over the years that I have bonded or earthed (or whatever other term you may wish it to be called) south of the main isolating device and both sides of any device connected within the main pipework by unions since forever (well since early 70's).

Additionally I have tended to run additional G/Y wires to bathrooms and kitchens much to the concern of the DNO guy sent out to reconnect my supply after a full house refurb where I'd had a temp supply of only a 15A fuse and double 13A socket for 18 months.

I assumed the big brass fitting in the earlier pictures was the original union for the lead meter tail.

SUNRAY · 20 Oct 2018

AlanE said:
OK I agree heating radiators was pushing it a bit!

It wasn't pushing it in the 70's, in fact I used to have to earth metal hinges and handle on wooden windows too.

333rocky333 · 20 Oct 2018

ban-all-sheds said:
Which reg #?

547-02-02 in 16th ed and 544.1.2 in 17th ed

AlanE · 20 Oct 2018

The picture that Rocky posted up looks like it is the Transco method of lining old steel service pipes the parts for doing this are not available to normal RGI's.

It looks as if the steel part with the securing bolts showing should in fact be bolted to the existing steel pipe where in this case it isn't.

I also thought the actual MDPE was showing but what they have left the new plastic too long and covered their backsides by wrapping a length of tape that dispicts the on/off position same as that bit of tape on the anaconda.

Bonding wire should be nearer the meter certainly before that contraption someone has put together using inappropiate fittings. The left hand part is in reality a meter union and should only be used in that position.

Two bonding wires would date back to the times when wiring regs permitted a single wire to bond the two utilities provided that the wire was stripped of insulation at one bond and connected to the second but not cut and then joined at one of the bonds.

AlanE · 20 Oct 2018

Copy of the specifications requires when requesting the use of combined neutral earth earthing terminal.
Note where it says:
Equipotential bonding is required between the earth conductor and the following extraneous conductive parts:
* Water installation pipes
* Gas installation pipes
* Other installations pipework and ducting
* Central heating and air condition systems
* Exposed metallic structural parts of the building

That requirement is exactly the same for all the various supply companies I know of.

Another scenario of not bonding all the other services, loss of neutral connector causes the main earth terminal to rise to the same level as the live supply. The case of a lot of equipment will also rise whilst the remaining metalwork in the property will be nearer true earth potential namely above lethal shock level.

333rocky333 · 20 Oct 2018

SUNRAY said:
It wasn't pushing it in the 70's, in fact I used to have to earth metal hinges and handle on wooden windows too.

I like John heard rumours of that. i trained to the 14th and was not aware it was necessary, I dont recall a 15th update course so I brought my own books and again was not aware of that, a typical 15th install was as below.
Note the reference to METAL Extraneous pipes and the Gas bond on meter side

20181020_211017

333rocky333
20 Oct 2018

20181020_213033

333rocky333
20 Oct 2018

EFLImpudence · 20 Oct 2018

SUNRAY said:
It wasn't pushing it in the 70's, in fact I used to have to earth metal hinges and handle on wooden windows too.

I think that has (in this thread) been dispelled as myth and was the result of misunderstanding the regulations in exactly the same way as in this thread.

However bonding a radiator might be a good example for thinking about bonding.

For example the pipes attached to the radiator might or might not require bonding.

a) They do run in the ground from room to room therefore they do require Main Bonding - but only once as the resistance of the pipes is much lower than any wire.

b) They do not run in the ground therefore they do NOT require Main Bonding.

c) In either case the pipes still might require Supplementary Bonding in a special location (e.g. bathroom).

Whichever case applies, a, b, or c they are correctly bonded as per the electrical requirements.

SO, what can the radiator do, or cause, that is not covered by the correct bonding of the two pipes connected to it?
Indeed, the radiator, by virtue of connecting the two pipes, could be acting as a satisfactory supplementary bond itself - leaving the question of does a supplementary bonding conductor itself require supplementary bonding?
Could the answer be NO?

EFLImpudence · 20 Oct 2018

AlanE said:
Copy of the specifications requires when requesting the use of combined neutral earth earthing terminal.
Note where it says:
Equipotential bonding is required between the earth conductor and the following extraneous conductive parts:
* Water installation pipes
* Gas installation pipes
* Other installations pipework and ducting
* Central heating and air condition systems
* Exposed metallic structural parts of the building

That requirement is exactly the same for all the various supply companies I know of.

That quite clearly is a copy of the previous link but crucially omitting relevant parts.

Whoever wrote that is obviously the cause of your misunderstanding.

333rocky333 · 20 Oct 2018

AlanE said:
Copy of the specifications requires when requesting the use of combined neutral earth earthing terminal.
Note where it says:
Equipotential bonding is required between the earth conductor and the following extraneous conductive parts:
* Water installation pipes
* Gas installation pipes
* Other installations pipework and ducting
* Central heating and air condition systems
* Exposed metallic structural parts of the building

That requirement is exactly the same for all the various supply companies I know of.

Another scenario of not bonding all the other services, loss of neutral connector causes the main earth terminal to rise to the same level as the live supply. The case of a lot of equipment will also rise whilst the remaining metalwork in the property will be nearer true earth potential namely above lethal shock level.

I must be getting mixed up here No one has disputed that have they, Water and gas are not always Extraneus conductive parts though, it is those pipes that do NOT need bonding to the earth conductor

Surely the remaining metal is safe as it is NOT connected to earth, if it was connected to earth then it would have been Extraneous and therefore should have been bonded to earth.
Furthermore we also had supplementary bonding to back up

SUNRAY · 20 Oct 2018

333rocky333 said:
I like John heard rumours of that. i trained to the 14th and was not aware it was necessary, I dont recall a 15th update course so I brought my own books and again was not aware of that, a typical 15th install was as below.
Note the reference to METAL Extraneous pipes and the Gas bond on meter side

20181020_211017

333rocky333

20 Oct 2018

EFLImpudence said:
I think that has (in this thread) been dispelled as myth and was the result of misunderstanding the regulations in exactly the same way as in this thread.

However bonding a radiator might be a good example for thinking about bonding.

For example the pipes attached to the radiator might or might not require bonding.

a) They do run in the ground from room to room therefore they do require Main Bonding - but only once as the resistance of the pipes is much lower than any wire.

b) They do not run in the ground therefore they do NOT require Main Bonding.

c) In either case the pipes still might require Supplementary Bonding in a special location (e.g. bathroom).

Whichever case applies, a, b, or c they are correctly bonded as per the electrical requirements.

SO, what can the radiator do, or cause, that is not covered by the correct bonding of the two pipes connected to it?
Indeed, the radiator, by virtue of connecting the two pipes, could be acting as a satisfactory supplementary bond itself - leaving the question of does a supplementary bonding conductor itself require supplementary bonding?
Could the answer be NO?

From about '73 to '77 I did a lot of new build work and I can assure everyone that the inspectors would check the resistance to earth of every single metal window and door handle and a random sample of hinges. They checked that all metal services entering a room were bonded, including the radiator. Without it the supply would not be connected.

As I recall, the regs implied something like 'all exposed metal work' and it was far too easy to interpret it far and away above it's intent. I'm totally convinced some inspectors, or their companies!, took it to ridiculous extremes but there was no power without conforming .

AlanE · 20 Oct 2018

And a final note on wiring regs isn't it about time they had some true legality?

At the moment they compleatly lack any authority which applies to anyone calling themselves an electrician.

All you can do if you find a dangerous situation, even if life threatening, is issue a warning note to the responsible person. True?

At least an RGI, if they find an immediatly dangerous situation, is required to seek the responsible persons permission to cap off the faulty/dangerous situation. Yes they have the option to say no. If this is the case they normally change their minds when told that they risk a good chance of loosing their entire gas supply if they continue to decline.

RGI is duty bound to notify gas transporter who will then arrange for engineer to attend, normally within half hour to an hour. Their normal action, as it reduces risk of confrontation, is to simply isolate supply at meter position and go. Affectionatly known as TOFO's.

EFLImpudence · 20 Oct 2018

SUNRAY said:
From about '73 to '77 I did a lot of new build work and I can assure everyone that the inspectors would check the resistance to earth of every single metal window and door handle and a random sample of hinges. They checked that all metal services entering a room were bonded,

You mean 'earthed unnecessarily'. You cannot bond - equalise potential - that which has no potential.

It's a silly example but what is the difference between a door hinge and a spoon? Apart from the fact that you don't put door hinges in your mouth.

including the radiator. Without it the supply would not be connected.

They clearly had no idea what they were doing.
NATICKWTAD.

As I recall, the regs implied something like 'all exposed metal work' and it was far too easy to interpret it far and away above it's intent. I'm totally convinced some inspectors, or their companies!, took it to ridiculous extremes but there was no power without conforming .

I doubt that is what it actually said - or the electrical industry was led by idiots.

EFLImpudence · 20 Oct 2018

AlanE said:
And a final note on wiring regs isn't it about time they had some true legality?

Not if they are as bad as it seems.

At the moment they compleatly lack any authority which applies to anyone calling themselves an electrician.

Electricians don't need regulations. They have the laws of physics.
Only people who don't know what they are doing need rules.

All you can do if you find a dangerous situation, even if life threatening, is issue a warning note to the responsible person. True?

I suppose. While suicide is not illegal, if people take no notice it would be their fault.

At least an RGI, if they find an immediatly dangerous situation, is required to seek the responsible persons permission to cap off the faulty/dangerous situation. Yes they have the option to say no. If this is the case they normally change their minds when told that they risk a good chance of loosing their entire gas supply if they continue to decline.

Electrical installations are festooned with safety devices. Gas leaks are undetectable by such devices - and then the house explodes.

RGI is duty bound to notify gas transporter who will then arrange for engineer to attend, normally within half hour to an hour. Their normal action, as it reduces risk of confrontation, is to simply isolate supply at meter position and go. Affectionatly known as TOFO's.

If the main fuse blows, then they have to wait until the supplier - and electrician - attends.

If gas had a similar device to disconnect the supply in the event of a fault then it would be the same.

Perhaps if you could see a regulation was wrong rather than blindly follow whatever is written, you might feel differently.

What if you came upon a 60 mph speed limit sign someone had fitted upside down, what would you do?

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18th 544.1.2

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ban-all-sheds

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