When replacing a switchboard ( such as a panel and frame or a Federal enclosure with semi-rewireable fuses ) with a circuit breaker switchboard , in an installation where the main earthing conductor is connected to the general mass of earth via a conductive water pipe , do I need to upgrade the earthing system , including the installation of an earth electrode ?

The existing earthing system can remain if : a ) The connection of the main earthing conductor to the conductive water pipe is accessible for inspection and testing ; b ) The continuity of the main earthing conductor from the main switchboard to the connection at the electrode or conductive water pipe proves to be less than 2 Ohms and c ) The metallic conductive water pipe remains in contact with the general mass of earth ( the underground section ).

A new earthing system must be installed when : a ) The connection of the earthing conductor is not accessible b ) The main earth is damaged c ) The continuity between the electrode or conductive water pipe and main switchboard proves more than 2ohms or d ) The metallic conductive water pipe is no longer in contact with the general mass of earth .

AS / NZS 3000:2007

Clause 1.9

Where the main earthing conductor is connected directly to a conductive water system , but the connection is not visible , is a test between the main earth conductor at the switchboard and the water pipe at any point a valid way of proving the main earth connection ?

No . It would not prove the connection as there may be alternate paths , such as a conductor connected between the main earth conductor and a water heater . The minimum test requirement is a continuity test of the main earth conductor performed between the main earth bar or main earth conductor at the main switchboard to the main earth conductor that is disconnected from the water pipe at the location where the main earth conductor connects to the water pipe . Upon reconnection of the main earth conductor to the water pipe , a continuity test between the water pipe and the conductor should be performed to ensure the reconnection is effective .

AS / NZS 3000:2007

Clause 8.3.5

I have been advised that all swimming pools that have a conductive structure are required to be provided with a bonding conductor connection point . That includes if there are no exposed conductive parts of any electrical equipment in the classified pool zones , and all exposed conductive parts of electrical equipment in contact with the pool water , including the water in the circulation or filtering system , are separated by double insulation . Is this correct ?

Yes . Where the pool or spa structure is conductive , all extraneous conductive parts , including the reinforcing metal of the pool shell or deck , shall be connected to an equipotential bonding connection point .

The equipotential bonding connection point shall be : a ) located in a position that will be accessible with space for connections to be made after pool construction ( for example , a pit located adjacent to the pool equipment ) b ) identified by marking of the location on the switchboard at which the circuits supplying the pool or spa originate , or other permanent location c ) of suitable design and construction in accordance with Clause 3.7 of AS / NZS 3000:2007 d ) protected against mechanical damage in accordance with Clause 5.5.5.2 of AS / NZS 3000:2007 and e ) protected against corrosion in accordance with Clause 5.5.5.3 of AS / NZS 3000:2007 .

AS / NZS 3000:2007

Clause 5.6.2.6