Supplementary Equipotential Bonding to the 17th Edition

[securespark]

I have copied the following from another thread here. The reason is that I and others have been saying it's OK to do away with SEB's if you have MEB's in place & all circuits in the bathroom are 30mA RCD-protected.

That was in the DPC. However, the 17th as published has changed:


The DPC did say you can do away with supplementary if:

1. you have all circuits 30mA RCD-protected, and

2. If you have MEB's to all services etc.


It may be OK still to omit SEB, but the final regs have changed from the DPC:

Quote:

In a building with a Protective Equipotential Bonding system in accordance with 411.3.1.2, supplementary EB may be omitted where all of the following conditions are met:

1. All final circuits of the location comply with the requirements for ADS according to 411.3.2.

2. All final circuits of the location have additional protection by means of an RCD in accordance with 701.411.3.3 (ie 30ma / 40ms at 5x)

3. All extraneous conductive parts of the location are effectively connected to the PEB according to 411.3.1.2.

Note: The effectiveness of the connection of extraneous conductive parts in the location to the main earthing terminal may be assessed, where necessary, by the application of 415.2.2.


415.2.2 (in part)

Confirm that the resistance between simultaneously accessible exposed conductive parts and extraneous conductive parts fulfills the following condition:

R is less than or equal to 50 V/Ia,

where Ia is the operating current of the protective device:

for RCD's, I delta n.

for overcurrent devices, the current causing automatic operation in 5s.

 

[ebee]

Therefore if all plastic piping etc then condition 3 can not be met therefore you must supp bond .
LOL.

seriously though how do you check reliable and continuos connection of metal pipework between MEB & bathroom & what if it subsequently gets a piece of plastic installed between?

Methinks keeping supp bonding would have been a safer option.

 

[Spark123]

If plastic pipes were used would they be extraneous conductive parts?

 

[ebee]

If plastic pipes were used would they be extraneous conductive parts?

No there would not, therefore they can not be evffectivlely connected to the MEB, because they do not exist, therefore condition 3 can not be met.

 

[Spark123]

"3. All extraneous conductive parts of the location are effectively connected to the PEB according to 411.3.1.2."

If placcy pipes are used then they are not extraneous hence are exempt from this surely

 

[GaryMo]

If placcy pipes are used then they are not extraneous hence are exempt from this surely

That's how I see it.
If there isn't anything extraneous then wouldn't you say condition 3 becomes exempt?

 

[securespark]

More food for thought, huh?

 

[ebee]

Yes of course.
Just my wicked sense of humour nit picking.
LOL

 

[securespark]

"3. All extraneous conductive parts of the location are effectively connected to the PEB according to 411.3.1.2."

If placcy pipes are used then they are not extraneous hence are exempt from this surely

I would certainly think so. But, if not, then unless you can satisfy number 3, then SEB has to be carried out.

Bummer!

 

[GaryMo]

I would certainly think so. But, if not, then unless you can satisfy number 3, then SEB has to be carried out.

I don't think there's any 'ifs' about it. Plastic pipes aren't extraneous so condition 3 cannot apply.

 

[securespark]

My wording was confusing, sorry.

I meant that if the pipes were not plastic, then you'd probably have to bond.