AS/NZS4777.1 (2016) release and 4777.2 Update
Kristin Gillies, September 30, 2016
30 September 2016 - AS/NZS4777.1 (2016) release and 4777.2 Update
1) AS/NZS4777.1 (2016) has now been released.
The long awaited update of 4777.1 (standard for the installation requirements for grid connected inverters) has just been released.
It is available for purchase from https://infostore.saiglobal.com/store/
Major changes in this standard include:
I. Single phase systems restricted to 5kW per phase
II. Three phase systems are allowed a maximum of 5kW unbalance per phase
III. Max. 2% voltage rise allowed from the inverter to the point of supply.
IV. Systems > 30kW require additional central voltage/frequency protection at the main switchboard
V. Allowance and standardization of export limiting controls
VI. RCDs allowed to feed an inverter
VII. Wiring PV systems with storage
VIII. Wiring standby systems (grid connected with standalone feature)
This standard is not mandatory in New Zealand until it is cited in the NZ Electricity Regulations.
2) Single phase inverters on a 3 phase supply.
A reminder that smart meters in New Zealand are configured to register import and export per phase. So it is important to match the loads with the PV on each phase.
For example, if there is a balanced load consuming 1kW on each phase, and a single phase PV system producing 3kW, then over an hour, the meter will register consumption of 1kWh on 2 phases and export of 2kWh on the third phase. If the owner is paying 30c/unit for power, and gets 8c/unit feed in, then the owner will be using 60-16=44c of electricity for that hour (ie you are being paid 8c/unit for electricity that you are immediately buying back for 30c). If all the loads where put on the same phase as the PV, then there would be 0 cost for that electricity. Note that what is displayed on the face of the meter is not what is being internally registered.
This may cause some discussion with the Lines Company, as they generally want a balanced load across the phases. Alternatively fit a 3 phase inverter system.
In Australia, the phases are aggregated, so this is not an issue.
3) AS/NZS 4777.2 – the saga continues.
The Electricity Authority (EA) has made a change to Part 1A of the Code which mandates how the Lines Companies process applications for distributed generation.
From EA:
“AS/NZS4777:2 2015 is incorporated into the Code from 20 October 2016, refer to http://www.ea.govt.nz/dmsdocument/21272 .
Note the following:
1) SSDG applications made under Part 1 can use any inverter standard approved by the distributor
2) SSDG applications made under Part 1A
a. to 19 October 2016 can only be made using AS4777:2 2005 compliant inverters
b. from 20 October 2016 can only be made using AS/NZS4777:2 2015 compliant inverters
The Code sets out the requirements for what standard must be used for the Part 1A application process, and not what standards are enforced (by inspectors and Energy Safety).
Our previous Tech Update regarding AS/NZS 4777.2 (2015) not being mandatory until cited still applies. It depends on how the Lines Companies handle the application.
