Update issued on further extension of Central Protection Exemption
This update follows Notice to Industry on Central Protection Exemption provided by the Office of the Technical Regulator earlier this year.
Read that Notice to Industry: Central Protection Exemption
Recap of the exemption in place
In response to SA Power Networks and industry feedback on central protection requirement as specified in AS/NZS 4777.1:2016, the Office of the Technical Regulator (OTR) provided an exemption to Network Protection Unit (NPU) requirements.
This simplifies the connection process for customers in networks that share a common connection point such as retirement villages, aged care, community and strata title.
A condition of the exemption is that the associated National Meter Identifier (NMI) will host no more than 30kVA of inverter-based generation. In many installations where the exemption is intended to be applicable it is often the case that there is a single ‘Parent’ meter which is market facing and is a customer of SA Power Networks. The tenants are then privately billed using an independent revenue metering arrangement and are customers of the Embedded Network owner/operator.
Extension of the exemption
In response to ongoing feedback to the OTR from SA Power Networks and industry, further revision has been made to the central protection requirement. The exemption from OTR is now extended to individual energy consumers within an Embedded Network for those with private metering and/or billing arrangements. In this situation, it is permissible that the ‘Parent’ NMI hosts more than 30kVA of inverter-based generation, so long as the ‘Child’ remains less than 30kVA.
To be eligible, the remaining conditions of the exemption are still required to be met:
- The combined inverter generating systems nameplate at the connection point does not exceed 200 kVA;
- The installation is a multiple electrical installation comprised of either multiple residential or commercial premises that are separately occupied or owned by different persons or corporate entities.
Illustrations of eligible arrangements are shown below where NMI refers to a market facing meter and is a customer of SA Power Networks.
Figure 1 – Exempt from Central Protection as Child Meters are less than 30kVA
Figure 2 – Exempt from Central Protection as NMIs are less than 30kVA
This decision will further simplify the connection process for customers in Embedded Networks that share a common connection point such as retirement villages, aged care, community, and strata title, and remove the cost barriers associated with the requirements for customers in taking up solar.
Any questions?
For more information on the requirements of this standing exemption, please contact:
otr.electricityinfrastructure@sa.gov.au