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Technical guidance for solar installers

If your application is for an embedded generation system that meets the following criteria, then in most instances, it will not require a technical review by Western Power before it can be approved: 

  • the system is a solar photovoltaic (PV) system
  • the PV system is on the published Clean Energy Council approved product list
  • the total capacity of the inverters at the site is less than (or equal to) 5 kVA
  • the property where the system is to be installed is in the Perth metropolitan area (including Fremantle and Mandurah) or in the township of Albany, Bunbury, Geraldton or Kalgoorlie.
  • supply to property after installation of system is within Western Power standard supply.

If your proposed embedded generation system does not meet the above criteria, then further checks are required and the application may require a technical review before being approved.

To select an embedded generation system suitable for your individual point of supply please see our Basic Embedded Generation Connection Technical Requirements and Distribution Customer Connections Requirements.

During a technical review we will determine whether the proposed inverter embedded generation system meets technical requirements for connection. If it does not, we will provide information on alternative options for you to consider. These options will help you decide whether to alter your proposed system to suit your point of supply, or to modify your point of supply so that the proposed system can be connected.

Any application for a single phase inverter with a capacity between 2.5kVA and 3 kVA will need to pass the 1% voltage rise on the service lead check, and meet all other applicable eligibility criteria to be approved.

Any application for a single phase inverter on a 3 phase supply over 3 kVA will not be approved as the voltage rise on the service lead will exceed 1%.

In some areas of the Western Power network, there may be particular feeders with high levels of penetration or a high number of connections on a long feeder. The network hosting capacity check is the means of checking that the local network area can accommodate the customer's proposed system capacity.

Excessive voltage rise within the customer installation due to the inverter embedded generator can result in nuisance tripping and power quality issues not related to the network connection, and is the responsibility of the customer and the supplier of the system.

Minimising nuisance tripping on new inverter systems

When installing a new inverter system, the installer must choose settings compliant with AS/NZS 4777.2:2015 and Western Power’s requirements. To minimise nuisance tripping of inverters, the installers must check that:

  1. Voltage rise within the customer installation is kept to a minimum. Maximum voltage rise within the installation is to be less than 2 per cent or 4.8V. Ideally, 1 per cent or less voltage rise is recommended as this lessens the likelihood of nuisance tripping.
  2. The volt-watt power quality mode must be enabled with default settings, as given in the Australian Standard. This mode reduces the inverter power output when needed, to prevent exceeding the voltage limits. If this mode is not enabled, the inverter may experience frequent nuisance tripping when the network is lightly loaded.
  3. The setting for “sustained operation for voltage variations” is permitted to be set up to 258V. This setting allows for approximately 4V of voltage rise within the customer installation when the network voltage is at the upper limit allowable by Western Power.

In some cases it has been reported that the inverters are not connecting due to the voltage being above 253V. This is correct behaviour for the inverter and no settings need changing. After completion of an installation returning air conditioning, other appliances and load to their normal operating state will in some cases lower the voltage so that the inverter will connect.

What should I do if frequent nuisance tripping persists?

If you’ve checked these points and that there are no other installation problems, call us on 13 13 51.

The expected service times are within 5 days for metropolitan areas and 10 days for country areas - we will let suppliers and installers know if it is going to take longer. 

There is a Technical Rules exemption which applies for eligible inverter systems and it contains two parts which specify modified Technical Rules requirements which would otherwise apply once the aggregate installed connection point capacity is in the range from 30 kVA to 1 MVA.

Type certified AS 4777 and IEC 62116 compliant inverters have required performance characteristics and may qualify for all, or part, of the 30 kVA to 1 MVA inverter protection requirements exemption on the Technical Rules page.

  1. Duplication of protection

Given the additional built-in protection functionality in eligible inverter systems, the Rules requirement for duplicated connection point protection does not apply at or below 1 MVA.

  1. Earth fault protection (or NVD) for low voltage (LV) inverter connections

The exemption may also remove the requirement for earth fault protection for eligible LV (240 V and 415 V) connected systems rated at or below 1 MVA.

Other small generator systems rated at greater than 30 kVA, including other inverters connecting to the distribution system, maintain the existing requirement to meet section 3.6 of the Technical Rules. If you have any concerns in relation to this or wish to explore case-by-case exemptions from these Rules, please get in touch with us, preferably early in the connection application process.

We continue to pursue options to connect generator systems to the network safely, reliably and affordably.