Earth bonding and Earth Cable Runs

[EFLImpudence]

Make of it what you will

411.3.1.2(iv)

 

[aboardepsilon]

Make of it what you will

411.3.1.2(iv)

it says .
All extraneous conductive parts in an installation must be connected to the main earthing terminal by main protective bonding conductors. This applies to the metallic sheath of a telecommunications cable where permission from the owner of the cable must be obtained.

all the best.markj

 

[EFLImpudence]

Not in my book - 411.3.1.2 says

...main protective bonding...shall connect to the main earthing terminal extraneous-conductive parts including...

...

Central heating...

 

[flameport]

Central heating in that instance would refer to systems installed in block of flats, where heating pipes from a central boiler pass through all of the flats.
Or perhaps where waste heat from power stations is used to heat a local housing estate.

411.3.1.2 does not apply to radiators, pipes and a boiler in a normal house, because none of those items will be extraneous conductive parts.

 

[aboardepsilon]

Did the house wring 27 years ago ..........just found out my earth cable going to the rising water main is only 6mm..replacing it involves taking the sodding bath out ..that's if i cant pull the new through with the old.

all the best.markj

 

[EFLImpudence]

Central heating in that instance would refer to systems installed in block of flats, where heating pipes from a central boiler pass through all of the flats.
Or perhaps where waste heat from power stations is used to heat a local housing estate.

Why is this reasoning not applied to the water and gas installations?

411.3.1.2 does not apply to radiators, pipes and a boiler in a normal house,

411.3.1.2 is considering main protective bonding so does not mention these items. It does mention connecting to the main earthing terminal - central heating.

because none of those items will be extraneous conductive parts.

Really ?

 

[londonboy]

I predict 10 pages..?

 

[RF Lighting]

Central heating in that instance would refer to systems installed in block of flats, where heating pipes from a central boiler pass through all of the flats.
Or perhaps where waste heat from power stations is used to heat a local housing estate.

Why is this reasoning not applied to the water and gas installations?

It is. As virtually all water and gas supplies enter from outside the property, virtually all of them are extraneous-conductive-parts, and therefore require protective equipotential bonding.

411.3.1.2 does not apply to radiators, pipes and a boiler in a normal house,

411.3.1.2 is considering main protective bonding so does not mention these items. It does mention connecting to the main earthing terminal - central heating.

Read it again. It says "In each installation main protective bonding conductors complying with Chapter 54 shall connect to the main earthing terminal extraneous-conductive-parts including the following:"

Note the part I have highlighted in red. If it isn't an extraneous-conductive-part then it does NOT require protective bonding to be connected.

because none of those items will be extraneous conductive parts.

Really ?

Really.

Do you actually understand what an extraneous-conductive-part is, and what causes it to become an extraneous-conductive-part?

 

[aboardepsilon]

I think it needs to be done anyway ..whatever the rules ..because you have ptfe on joints ..etc ..the more you can connect everything up ..the better you are protected...a rad could be non conductive through its inlet pipe ..but conductive through its return pipe...and for what it costs when you DIY it ..why not .

could be different if you had to pay someone else to do it ...then a tiny bit more safety will cost you dearly...so the argument comes down to labour cost really.
plus you could be selling house in the future ..and survey come back with report of no earth bonding on these pipes ..putting off buyer ..
also heard stories of BG not wanting to work on systems that didn't have it ...using it as an excuse.

all the best.markj

 

[RF Lighting]

No it doesn't need to be done. It's completeley pointless, a waste of time and materials even.

It does not make the installation any safer. In some circumstances it can actually make the installation less safe.

Central heating systems do not require main protective bonding connecting to them unless they contain extraneous-conductive-part(s) which domestic systems very rarely do, and boilers, rads and the like do not require any form of supplementary bonding.

 

[Qedelec]

RF's right, as long as all circuits meet the current regs ie RCD protected or Earthed Mechanically Protected, then Supplementary Bonding is not required.

 

[EFLImpudence]

Read it again. It says "In each installation main protective bonding conductors complying with Chapter 54 shall connect to the main earthing terminal extraneous-conductive-parts including the following:"

(iv) Central heating

Do you actually understand what an extraneous-conductive-part is, and what causes it to become an extraneous-conductive-part?

Are you saying radiators, pipes and boilers can never be extraneous-conductive parts?

The central heating is virtually bound to be connected to the gas and water.
Nevertheless it is specifically mentioned in the regulations as needing MAIN protective bonding?

 

[ricicle]

If you cannot grasp the theory behind Main Protective Bonding then you are some way off becoming a competant electrician.....

 

[aboardepsilon]

well i don't know if this is relevant to it ..
a few years ago my electricity was tripping the rcd on the odd occasion ...i did not put two and two together....and work out that it was the immersion heater .until after about the 3rd or 4th trip ..when it didn't want to reset ..

until i turned off the immersion mcb.

a day or two later i investigated .took the immersion heater out ..and it had rotted.......the copper covering the elements was gone in places ..and the inner core was exposed .

i had non of this earth bonding then, except the water main and the main electric riser . ..but ..it lead me to think of ..what if i was having a bath when this happened ..

all the best.markj

 

[EFLImpudence]

Merely pointing out what is in the regulations.

Then statements like this are written -

411.3.1.2 does not apply to radiators, pipes and a boiler in a normal house, because none of those items will be extraneous conductive parts.

I agree 411.3.1.2 does not apply but do you agree with the rest of it.