Heat pumps
Heat pump switchboard capacity checks in New Zealand
A switchboard should be checked before a fixed heat pump is connected in a New Zealand home, but the check does not mean every installation needs a full board replacement. The electrician considers the selected unit's electrical input, the proposed circuit, spare capacity, existing installation condition and required protection.
Check the heat pump model before the switchboard
Start with the supplier's quote, full model number and manufacturer instructions. The electrical information should show rated voltage, input current or power, recommended fuse or circuit protection, cable requirements and the wiring arrangement between indoor and outdoor units.
Heating capacity and electrical input are different figures. A breaker or cable cannot be selected from advertised heating output alone. Changing the unit after the electrical quote may change the circuit and cable requirements, so send the final model before work starts.
Confirm spare capacity on the proposed circuit
An existing circuit is suitable only when it has enough spare capacity and the proposed connection meets the unit instructions and New Zealand electrical requirements. The electrician identifies what else the circuit supplies and considers how those loads are used at other times.
Known tripping, warm fittings, damaged wiring or unclear alterations need investigation before extra load is added. A capacity problem cannot be solved by fitting a larger breaker or fuse without verifying the cable and connected equipment.
Choose an existing or dedicated circuit
EECA's Good Practice Guide says a heat pump may use a suitable existing circuit with sufficient spare capacity or a separate dedicated circuit, depending on the unit input and the existing installation. New buildings should use a dedicated circuit, and a manufacturer may require one for a specific model.
A separate circuit is often appropriate when the existing circuit is heavily loaded, difficult to verify, poorly routed or unable to take the required protection. The final choice follows the model and site rather than a universal rule.
Assess switchboard condition and protection
The switchboard check covers more than an empty physical slot. The electrician considers board type and condition, available ways, existing protection, main supply arrangement, circuit identification, earthing and any warning signs around the installation.
Old rewireable fuses, heat damage, loose parts, unexplained tripping and lack of usable space can change the work. If the board has scorching, unusual heat or a burning smell, keep clear and arrange a licensed inspection before treating the job as ordinary heat pump planning.
Set the switchboard work from the inspection
An older board is not automatically replaced for a heat pump. If the board and proposed circuit can safely support compliant work, the scope may be limited to the required connection, protection and labelling. Where capacity, condition or safe connection space is inadequate, remedial work or a larger switchboard upgrade may be needed.
UBL Electrical carries out heat pump electrical work and switchboard assessments across metropolitan Auckland. Send the final model details, proposed unit locations and a closed-cover switchboard photograph for a free quote, or call 021 0284 3210.
- Heat pump brand, full model and supplier quote
- Manufacturer's electrical installation instructions
- Proposed indoor and outdoor unit positions
- Closed-cover photograph of the complete switchboard
- Known circuit labels and tripping history
- Other planned loads and cable-route constraints