2-or Split-Phase Connections for Dual Occupancy

Ergon Energy Network and Energex would like to clarify the conditions where dual-phase (2-or split-phase) DNSP service point (Point Of Supply) will be permitted.

Where dual-phase DNSP service points are permitted for dual-occupancy arrangements

Dual-phase DNSP service point (Point Of Supply) connections are restricted to dual-occupancy dwellings comprising:

• no greater than, and no fewer than, two dwellings; and
• no greater than, and no fewer than, two customers (as defined by the Queensland Electricity Connection Manual); and
• where both dwellings are residential or domestic in nature; and
• the dwellings share the same lot of land or 2-Lot Community Title arrangements (2 lots sharing common property such as driveway and front yard under community title); and
• each dwelling is single-phase; and
• both dwellings shall have Development Approval (DA), Material Change of Use (MCU) approval or Building Approval from local council either as a duplex, dual-occupancy or secondary dwelling (with primary dwelling). The relevant approval shall be provided to the DNSP.

This may include the following:

• The two dwellings may be attached or detached. The dwellings may be of equal of differing floor areas.
• One of the two dwellings may be a secondary dwelling which is used in conjunction with, and sub-ordinate to, the other dwelling on the same lot of land. A secondary dwelling is commonly known as a granny flat.
• Apartment buildings, where the people live above and below each other, having a maximum of two dwellings.

Please note: Boarding houses, guest houses and hostels do not meet these criteria because they do not meet the definition of a dwelling.

For qualifying dual-occupancy arrangements:

• The meter board shall meet the requirements of QECM v4 clause 10.2.2.
• The meters for both dwellings shall be installed in a common meter board where the meter board meets location requirements of QECM v4 clause 9.8.1.1 and 9.8.4.
• There shall only be one DNSP Service Point for the dual-occupancy arrangement except where an additional DNSP Service Point may be permitted under Option LVXSA of QECM v4 clause 5.2.5.2.
• An example of the meter board wiring arrangement is provided in supporting diagram Figure 2 (see below)

2-or split-phase installations satisfying these requirements may be referred to as a dual-phase dual-occupancy. Examples of dual-phase dual-occupancy configurations (for 2- or split-phase DNSP supply) are illustrated in supporting diagram Figure 1 (see below)

Consumer mains neutral current

When you are considering 2- or split-phase supply for new or altered LV connections, the effect of possible future or existing Embedded Generation (EG) should be considered as single-phase supplementary supplies may cause neutral current to exceed that of the actives in particular in the consumer mains. This condition may occur when one phase is importing from the grid and the other exporting to the grid. EG can include Solar PV, batteries or a combination of both.

Changes to the QECM

To support these changes QECM v4 clause 5.3 Table 16 Note 4 is varied as per this alert.

Dual-occupancy Meter Panels

Meter panels shall meet the QECM minimum size of 480 (H) x 460 (W) mm. Although the Metering Installation Requirements (MIR v2.1) generally requires larger panels for dual-occupancy sites, Clause 9.3.3(2) allows smaller panels where future upgrades are unlikely. Accordingly, where a dual-occupancy installation has a panel of at least 480 (H) x 460 (W) mm that accommodates the requested metering, the DNSP will deem Clause 9.3.3(2) satisfied and connect supply without issuing a defect notice.

Refer to MIR Appendix A and B for equipment sizing and layout guidance.

Other connection options for dual-occupancy

This alert does not exclude other connections options for dual-occupancy premises permitted by the QECM, such as the use of 3-phase DNSP supply (where 3-phase DNSP supply is available).

Out-of-scope connections

Two dwellings with abutting structures, each on separate freehold lots, are not in this document’s scope and are not permitted to have a dual-phase DNSP Service Point (Point of Supply). They shall be supplied with the following:

• One DNSP Service Point and Connection Point per lot
• A main switchboard per lot

Supporting Diagrams

Figure 1: Example dual-phase dual-occupancy configurations with 2- or split-phase DNSP supply

Figure 2: Example common meter board wiring for dual-phase dual-occupancy arrangement (with 2-or split-phase DNSP supply)