Important note: standards and requirements can change

This article is general information only.

Electrical standards, Energex connection requirements, metering rules and Queensland electrical safety requirements can change over time. Every property is different, and the final requirements for a three-phase upgrade can only be confirmed after a site inspection by a licensed electrical contractor.

All electrical work must be completed by a licensed electrician. Homeowners should not attempt to alter switchboards, meter enclosures, consumer mains, points of attachment, earthing, service equipment or hardwired electrical circuits themselves.

Step 1: Confirm whether three-phase supply is available

The first step is checking whether three-phase supply is available to the property.

Some homes already have three-phase available nearby. Others may need additional network assessment or upgrades before a three-phase connection can be provided.

The electrician may need to check whether the home is supplied by:

• overhead service lines
• underground consumer mains
• a service pillar
• a property pole
• an existing single-phase service only

They may also need to check whether the existing point of attachment, service route and switchboard position are suitable for a three-phase supply.

If the network supply is not available or not adequate for the requested upgrade, Energex may need to assess the site before the work can progress.

Step 2: Calculate the home’s maximum demand

Before applying for a supply upgrade, the electrician needs to assess the expected maximum demand of the property.

Maximum demand is the calculated electrical demand that the installation is expected to place on the supply. It is especially important where the home is adding large loads such as EV charging, ducted air conditioning, batteries, large solar systems, pool equipment or induction cooking.

The electrician may consider:

• existing circuits
• air conditioning load
• cooking appliances
• hot water systems
• pool equipment
• solar inverter capacity
• battery charging
• EV charging
• shed or workshop loads
• future planned appliances
• whether load control or demand management is needed

This step matters because the requested supply capacity needs to match the actual and future use of the property.

If maximum demand is not assessed correctly, the upgrade may be delayed or the property may still experience capacity issues after the work is complete.

Step 3: Inspect the existing switchboard

A three-phase upgrade often exposes problems with older switchboards.

The existing switchboard may be too small, outdated, damaged, poorly located, or unsuitable for modern three-phase metering and protection equipment.

Common issues include:

• old ceramic fuses
• limited or missing safety switch protection
• no room for three-phase equipment
• old consumer mains
• outdated earthing
• asbestos-containing panels
• damaged meter boxes
• poor labelling
• overcrowded wiring
• no room for solar, battery or EV charger equipment

If your home already has an older board, a three-phase upgrade is often a good time to consider a full switchboard upgrade.

Step 4: Check whether the switchboard location is acceptable

The location of the switchboard and meter board can be one of the biggest issues in a three-phase upgrade.

The metering equipment needs to be safely accessible for electricians, the metering provider and the network provider. If the existing board is in a location that does not provide safe and ready access, it may need to be relocated.

Potential problem locations include:

• inside a garage
• behind a garage door
• inside a habitable room
• inside a roof space
• behind a locked gate
• behind fencing or landscaping
• too close to a driveway
• where a vehicle could hit it
• where future fences, gates, structures or landscaping may block access

This is why a licensed electrician needs to inspect the actual site. Two homes can both be upgrading to three-phase, but the work required can be completely different depending on the existing board location.

Step 5: Check trafficable areas and bollard requirements

If the meter board or switchboard is near a driveway, carport, garage entry, parking area or other trafficable location, vehicle impact protection may be required.

This may involve permanent protective barriers such as bollards.

The aim is to protect the electrical equipment from vehicle impact while still leaving safe access for electricians and metering staff.

Common examples include:

• a meter board beside a driveway
• a switchboard inside or near a carport
• a board mounted where cars reverse or park close to it
• a meter enclosure near a garage opening
• a board near a commercial or shared trafficable area

Bollards or barriers must be designed and positioned properly. They cannot simply block the board or make the working area unsafe.

In some cases, relocating the board may be a better option than trying to protect a poor location.

Step 6: Check the point of attachment

For homes supplied by overhead service lines, the point of attachment is where the network service line attaches to the property.

A three-phase upgrade may require changes to this point, especially where the existing attachment was only designed for the old single-phase service.

The electrician may need to check:

• whether the attachment point is structurally suitable
• whether the height is acceptable
• whether the service line clearances are suitable
• whether the attachment hardware is correct
• whether the service can reach the proposed board location
• whether the point of attachment needs to be moved
• whether a property pole is involved

If the point of attachment is old, damaged, in the wrong position or unsuitable for the upgraded service, it can become part of the upgrade scope.

Step 7: Replace or upgrade consumer mains

Consumer mains are the cables that run from the point of supply to the main switchboard.

When upgrading from single-phase to three-phase, the existing consumer mains are often not suitable because the property requires additional phases and may require a different cable size or route.

Depending on the property, this may involve:

• new overhead consumer mains
• new underground consumer mains
• conduit installation
• trenching
• new mains cable
• a new meter enclosure
• a new main switchboard
• coordination with Energex and the retailer

This is one reason three-phase upgrades can vary significantly in cost. A simple-looking upgrade can become more involved if the existing mains are old, undersized, damaged or not suitable for the new supply arrangement.

Step 8: Upgrade safety switches and circuit protection

A three-phase switchboard upgrade is also an opportunity to improve the electrical protection in the home.

Many older homes have only partial safety switch protection. Some may have one safety switch protecting only part of the property, while other circuits such as lights, air conditioning, ovens, hot water or pool equipment may not be protected in the same way.

During the upgrade, the electrician may need to assess:

• main switch arrangement
• circuit breakers
• safety switches
• RCBOs
• surge protection where suitable
• correct circuit separation
• load balancing across phases
• labelling of each circuit
• protection for solar, battery or EV charger circuits

If you are unsure whether your home has adequate safety switch protection, you can read more about safety switch installation.

Step 9: Check earthing and MEN connection

Earthing is a critical safety part of the electrical installation.

During a major upgrade, the electrician may need to check:

• main earth conductor
• earth electrode
• MEN connection
• bonding requirements
• earth continuity
• fault-loop impedance
• polarity
• insulation resistance
• RCD operation

Older homes can have earthing arrangements that need attention before a modern three-phase supply is connected.

This testing and verification work is one of the reasons a licensed electrician must be used.

Step 10: Allow for three-phase metering

Changing from single-phase to three-phase usually means metering changes are required.

The meter enclosure may need to allow for:

• three-phase metering
• meter isolation equipment
• network devices
• controlled load equipment
• solar metering
• battery or EV-related metering requirements
• smart meter installation
• safe working space and access

If the existing meter box is too small, damaged, inaccessible or in the wrong location, it may need to be replaced or relocated.

The customer-side switchboard, meter enclosure and wiring are generally the responsibility of the property owner, not Energex.

Step 11: Submit the connection paperwork

A three-phase upgrade normally requires connection paperwork before Energex attends.

This may include a connection application and an Electrical Work Request, commonly called an EWR.

The electrician may need to provide information such as:

• the property address
• number of phases required
• maximum demand in amps per phase
• whether supply is overhead or underground
• whether a property pole is present
• meter location
• main switchboard location
• whether the job involves a new switchboard
• whether EV charging is being installed
• whether solar or battery equipment is involved
• Ready for Test date
• electrical contractor details

If the connection application and EWR do not match, the job can be delayed.

Step 12: Coordinate with the electricity retailer

A three-phase upgrade can involve more than just the electrician and Energex.

The customer’s electricity retailer and metering provider may also be involved, especially where metering changes are required.

A typical supply upgrade may involve:

• the homeowner
• the licensed electrical contractor
• Energex
• the electricity retailer
• the metering provider

If any part of the process is missing, the upgrade may not proceed on the expected date.

Step 13: Complete the customer-side electrical work

Before Energex connects the upgraded supply, the licensed electrician needs to complete the required customer-side work.

This may include:

• installing new consumer mains
• installing a new meter enclosure
• relocating the switchboard
• upgrading the main switchboard
• installing three-phase main switchgear
• installing safety switches
• upgrading circuit protection
• upgrading earthing
• labelling circuits
• preparing space for metering
• balancing circuits across phases
• installing protective bollards or barriers where required
• making the site safe and ready for connection

Depending on the site, this may require a planned power outage and coordination with the network provider and retailer.

Step 14: Test the installation

Before the upgraded supply is connected or reconnected, the electrical contractor must test the installation and make sure it is electrically safe.

Testing may include:

• polarity testing
• insulation resistance testing
• earth continuity testing
• MEN verification
• fault-loop impedance testing
• RCD trip testing
• phase rotation where relevant
• main switch verification
• circuit protection checks
• labelling checks

The electrical contractor needs to be satisfied that the installation is safe and ready for connection.

Step 15: Energex completes the network-side connection

Once the site is ready and the paperwork is in place, Energex can attend to complete the network-side connection work.

Depending on the job, this may involve:

• disconnecting the old single-phase service
• altering the service line
• connecting the new three-phase supply
• changing service fusing
• coordinating with metering work
• energising the upgraded supply

The exact work depends on the property, supply type, service route and whether additional network work is required.