Bonding of conduit in kitchen floor

[ferg]

Not necessarily. There are plenty of all metal class 2 light fittings around.

I was waiting for that one.

I'll put it another way. Name a good reason not to earth it.

 

[Ian1981]

I was waiting for that one.

I'll put it another way. Name a good reason not to earth it.

We are not talking personal preference, we are saying is it a requirement of bs 7671

 

[Andy78]

As far as I can see, the reg that requires the earthing of exposed conductive parts is all encompassing and makes no exceptions.

The debate would be whether a part is an exposed conductive one or not.

 

[ferg]

That was my point but you made it in a much less smart arsey way.

I blame too much paperwork.

my apologies to Ian for said smart arse manner.

 

[static zap]

common sense dictates that if it's metal, contains wires and could be touched then it should be earthed.

It's in a kitchen , a chance of wet floors + it gets wet and becomes live !

 

[Ian1981]

Well as per guidance note 8 and regulation 412.2.4.1 A cable complying with the appropriate standards having a non metallic sheath is deemed to provide satisfactory basic protection and fault protection as does an item of class 2 equipment.
Class 2 equivalence aas pvc insulated and sheathed cables.
Hence containment such as metal tray or basket need not be earthed.
Cables in conduit are fully enclosed but I feel meet the same requirement

 

[Ian1981]

That was my point but you made it in a much less smart arsey way.

I blame too much paperwork.

my apologies to Ian for said smart arse manner.

No need pal
I took no offence

 

[Andy78]

411.3.1.1 is the reg that asks for earthing of exposed conductive parts. It makes no exception I can see nor references any of the regs pertaining to reinforced or double insulation.

 

[westward10]

Try regulation 412.1.1 double or reinforced insulation
Basic protection and fault protection are provided by reinforced insulation between live parts and accessible parts.
Regulation 412.2.

Singles don’t have reinforced insulation so understandably need containment as per regulation 521.10.1,where as twin and earth does, so I’d say it’s not necessarily a requirement to Earth the conduit if metal containing insulated and sheathed cables

T&E does not have reinforced insulation it has one layer of electrical insulation and an overall sheath which provides protection for the electrical insulation.

 

[Deleted member 26818]

There are exceptions to the requirement to Earth exposed-conductive-parts. One of which is where the wiring system is deemed to be double insulated.
410.3.9.

 

[Ian1981]

Regulation 412.2.4.1 I feel covers it in conjunction with ref 412.2 so I don’t think it’s a requirement.

 

[Andy78]

There are exceptions to the requirement to Earth exposed-conductive-parts. One of which is where the wiring system is deemed to be double insulated.

Can you point me in the right direction for that ?

 

[Deleted member 26818]

410.3.9.

 

[Andy78]

410.3.9.

Thanks. So 410.3.9 negates 411.3.1.1 as long as 412 is satisfied. Next question for me is does twin and earth satisfy 412 as double insulated ?

 

[Ian1981]

Well it’s deemed to provide satisfactory basic and fault protection as does an item of class 2 equipment.
I’m aware that every one bangs on about twin and earth is not class 2 blah blah but there it is.
Check out guidance note 8

 

[Deleted member 26818]

On second thoughts, I don't think T&E does satisfy the requirement to deemed double insulated.
I believe the CPC has to also be insulated and sheathed to comply.

 

[Andy78]

On second thoughts, I don't think T&E does satisfy the requirement to deemed double insulated.
I believe the CPC has to also be insulated and sheathed to comply.

I've heard that before in respect of bringing cable into class 2 accessories. Flex is acceptable because the cpc is insulated to the same voltage as the live conductors.

 

[Deleted member 26818]

In this instance though, the CPC of the T&E is not exposed within the enclosure.

 

[Ian1981]

The cpc only needs to carry fault current so it’s irrelevant if it’s not sleeved in this case as it’s not classed as a live conductor

 

[Risteard]

Try regulation 412.1.1 double or reinforced insulation
Basic protection and fault protection are provided by reinforced insulation between live parts and accessible parts.
Regulation 412.2.

Singles don’t have reinforced insulation so understandably need containment as per regulation 521.10.1,where as twin and earth does, so I’d say it’s not necessarily a requirement to Earth the conduit if metal containing insulated and sheathed cables

Insulated and sheathed cables do not provide either double or reinforced insulation. They merely provide mechanical protection.