[Geoffrey Brown]

From what I can see, looking at the Regulations, if the ESC relates to an installation or part of an installation, then ESR73A(1)(e) would apply unless ESR73A(3) and (4) can be applied.

[paul-smeetstopenergy-co-nz]

From a line mechanics point of view, I think establishing that an earth pin is in place is part of your visual prelivining tests, followed by polarity, voltage and loop impedance. Main earth conductor and equipotential bonding tests are a requirement for a new installation however in our company those are carried out by an electrical inspector prior to their approval to liven.

[Phil Cadman]

Depending on the type of work being carried out, ESR 73A is required to be complied with for any PEW on the installation or part installation, and ESR 38 is required to be complied with for any Works carried out.

But an ESC is required for both.

[Graeme Jackson]

Hi Craig, To attempt to answer your question, No, in my opinion it is not necessary to sight the earth pin or measure the resistance of the main earth earth lead. Both of these requirements are part of the inspection associated with high risk PEW and would be completed by an inspector issuing an ROI or an electrician issuing a COC for PEW.

Reg 73A states that “Before connecting to a power supply a low or extra-low voltage installation or part installation on which prescribed electrical work has been done, the person doing the connection must—

if the supply is from a MEN system, verify that there is a main earthing system.

There are other requirements but this bit of the regulation relates to earthing. How the person “verifies” that a main earthing system exists is not specified.

Our procedure allows our workers 2 options, A continuity test between the disconnected installation neutral and an independent earth, If the installation neutral is connected to earth via the installation earth electrode a low resistance will be measured, less than 10 Ohms is acceptable.

Or by using a voltage test between a network live source and the disconnected installation neutral, again if the neutral is connected to the earth electrode, voltage will be present.

Using these tests has identified a number of issues that a simple visual inspection would miss and as many installations have main earths connected to water pipes in locations that are not visible the test proves that a main earthing system exists and therefore meets the requirement of the regulation.

A bit long winded but hope it helps.