Amendment 2 of the Wiring Rules Critical Updates To Be Aware Of

AMENDMENT 2 OF THE WIRING RULES

CrItICAL UpDAteS tO be AWAre OF

THE TRANSITION PERIOD FOR AMENDMENT 2 OF THE WIRING RULES (AS/NZS 3000) APPLIES UNTIL OCTOBER 30 2021, EXCEPT FOR NSW WHICH TOOK EFFECT WHEN THE AMENDMENT WAS RELEASED ON APRIL 30 2020. SOME OF THE KEY REVISIONS RELATE TO RCDS, SWITCHROOM ACCESSIBILITY, EQUIPMENT CONNECTIONS, RESULTS RECORDING, AND COMPLIANCE WITH THE REVISED AS/NZS 61439 SERIES. IN ADDITION TO RESPONDING TO NEW TECHNOLOGY AND IMPROVED INSTALLATION TECHNIQUES, THE AMENDMENTS ALSO SEEK TO REMOVE CONFUSING WORDING AND IMPROVE READABILITY AND COMPLIANCE. WE TAKE A LOOK AT THE KEY UPDATES AND WHAT THEY MEAN FOR INSTALLERS.

If you’re adding a new moulded case circuit breaker (MCCB) and enclosure to an existing switchboard with <125 amps, does it need to comply with AS/NZS 61439?

If the capacity of the switchboard is not increased and the alterations are not affecting the structural integrity of the switchboard, then the additions can be made. Always consult a switchboard manufacturer before altering any large manufactured switchboards.

Are RCD socket outlets no longer permitted when adding a new GPO to an existing circuit without RCD protection?

They are not permitted for domestic installations if any socket outlets are added to an existing circuit, then the protection must be installed at the origin of the circuit. See clause 2.6.3.2.5. For non-domestic and non-residential installations, see clause 2.6.3.2.3.2 as the requirements are the same as for domestic apart from the exception that allows an RCD to be placed adjacent to the outlet.

Are these changes retrospective? If we find power boards in non-accessible areas, do we need to replace them?

No, changes to standards are never retrospective. NECAs recommendation is to remove the power boards.

Can you clarify the requirements for main switches and the colour and spacing requirements?

Main switches must be clearly marked and identifiable. Clause 2.3.3.5 details identification requirements. Main switches must be able to be secured in the open position. This can be achieved in a number of ways, including spacing. Some State Service Rules require a space between the main switch and other circuits.

Does equipment that has its own switchboard for parts of the equipment need to comply to the new switchboard requirements? For example chiller sets, large production line motor control centres (MCCs) etc?

Yes, the equipment meets the definition of a switchboard and the switchboard is either >125 amps or has a fault rating of greater then 10kA. There are some types of equipment that would not meet the definition of a switchboard, and this is where there can be confusion.

Is steel conduit suitable for WSX3 for mechanical protection? What about flexible steel conduit (anaconda)?

Galvanised medium tube is required as per clause H5.4. It is best to use Appendix H for all mechanical protection requirements as each scenario is unique.

Table I1 seems to upgrade the capacity of what would have an existing 8A rewireable fuse to a 10A circuit breaker. I believe it should be kept the same or downgraded due to the age of the wiring. Is this stating that an existing domestic light circuit with a 8A rewireable fuse is okay to replace with 10A RCBO?

Yes, you are reading the table correctly. The tripping characteristics of a circuit breaker should provide a better overcurrent protection then a rewireable fuse, so this could explain the difference in the ratings as well as the availability of the common sizes of circuit breakers.

Do three-phase 50 amp outlets need RCD protection for equipment directly connected over 32 amps?

No in non-domestic, nonresidential installations only, RCD protection is only required up to 32 amps. See clause 2.6.3.2.3.3.

When carrying out maintenance and repairs, such as fixing wiring only for circuits without RCDs, do we need to fit an RCD to those circuits? Or is it only for additions?

All alterations and additions need to have RCDs fitted to those circuits. This includes adding to an existing circuit. If you are carrying out maintenance and repairs, you are not required to install RCDs. However it is a good practice to put RCDs on wherever possible. Note: There are also other state regulations regarding rental properties and property sales and the installation of RCDs (and smoke alarms) before they change owners or leases.

What about AC RCD protection requirements for residential and commercial?

The use of Type AC RCDs is being phased out over the next two years. From April 2023, in NSW and October 2023 in all other states, only Type A RCDs will be allowed to be used in all scenarios.

I have been to new homes and still see circuit breakers on stove, cooktops and hot water systems. Is RCD protection required?

If you’re altering an existing switchboard to install meter protection devices, does the switchboard have to be upgraded to comply with AS/NZS 61439?

Any alterations need to be carried out in discussion with a switchboard manufacturer. The extent of the compliance to AS/NZS 61439 will depend on the nature and extent of the alterations.

Do we need to put an RCBO on solar?

Solar supplies are not classified as final subcircuits; therefore, they are not required to have an RCD fitted. It’s an alternate or supplement supply. However, you can install an RCD if required for cable protection as per clause 3.9.4.4 AS/NZS 3000. See also Clause 3.4.5 in AS/NZS 4777.1.

For new installations from 2018 onwards (after the new rules were introduced) RCDs are required on these circuits.

This applies to all circuits in domestic and residential installations. See clause 2.6.3.2.2.

What’s the best way to tackle a switchboard with asbestos which needs a RCBO to be installed?

Working on asbestos switchboards is not prohibited. Each state has regulator rules for working with asbestos and this includes bonded asbestos switchboards. The state regulator’s rules must be followed.

Is it mandatory to replace an asbestos switchboard panel when doing an upgrade from fuses to RCDs?

No, but it is strongly recommended to remove any asbestos switchboard panels. Again, it is important to follow state regulator requirements when working with asbestos.

When modifying an existing main switchboard (MSB) (100 amp) to add a new circuit breaker over 100 amps, does the existing board need to comply with AS/NZS 61439?

If there is an increase in the current rating of a switchboard, and it falls into either >125 amps or >10kA, then the requirements of AS/NZS 61439 apply.

To find out more about Amendment 2 of the Wiring Rules, contact the technical services offered by your local NECA Branch.