Size of Earth conductor

[Andrew_van_Zyl]

Just checking if I'm interpreting 10142 - "6.12 Earthing" correctly:-

Can I use 1.5mm earth cable with 2.5mm phase conductors?
-Single conductors - house wire.
-Small domestic flat not exceeding 50m lengths - more like 20m max
-20A circuit breaker

Many thanks!

[GCE]

If you look at Table 6.28(a) - on a C/Breaker where Im = 10x In and the CB is 20Amp the max length of earth wire at 1,5sqmm will be 30m

Don't run the 1,5sqmm to the geyser as that it another whole can of worms.

I would say you can run a 1,5sqmm as long as the length is under 30m

[Andrew_van_Zyl]

Many thanks GCE

[Andrew_van_Zyl]

If you look at Table 6.28(a) - on a C/Breaker where Im = 10x In and the CB is 20Amp the max length of earth wire at 1,5sqmm will be 30m

Don't run the 1,5sqmm to the geyser as that it another whole can of worms.

I would say you can run a 1,5sqmm as long as the length is under 30m

GCE - for educational purposes, what are the issues when using the same rationale for a geyser? 6.28(a) Would indicate it's ok?

[GCE]

GCE - for educational purposes, what are the issues when using the same rationale for a geyser? 6.28(a) Would indicate it's ok?

The bonding conductor must be 2,5sqmm - Was a long discussion in a previous thread and I have pasted the link and relevant pieces below

https://www.theforumsa.co.za/forums/showthread.php/28494-Geyser-earthing-and-bonding

If all pipes are pvc then the geyser needs to be bonded as per 6.16.2 - Then that is where the grey area of Twin & earth not having a full 2,5sqmm earth will come in.

6.13.2.2 Hot and cold water systems
Where the hot water system includes electric components and the water pipes
are of conducting material, hot and cold water systems shall be bonded
together and also be bonded to the earth continuity conductor system

6.16.2 Water heaters
NOTE Water heaters include geysers, instantaneous water heaters including units for
boiling water, heat pumps, solar systems, induction water heaters and the like (see also
6.16.1). electrode water heaters, steam generators and boilers are not included (refer
to 6.16.7)
6.16.2.1 All water heaters shall be bonded in accordance with 6.13 and a.c.
supply circuits shall be protected by earth leakage protection with IΔn not
exceeding 30 mA.
NOTE To mitigate nuisance earth leakage tripping, an additional earth leakage may
be provided.

6.13 Bonding
NOTE 1 The aim of bonding is to bring all the bonded parts to the same electrical
potential.
NOTE 2 No external conductor is required if compliance with the requirements for
continuity can be proved by the test in 8.6.2.

[Andrew_van_Zyl]

The bonding conductor must be 2,5sqmm - Was a long discussion in a previous thread and I have pasted the link and relevant pieces below
https://www.theforumsa.co.za/forums/...ng-and-bonding

Many thanks