Switchboards

Switchboard upgrades for Milford homes

Plenty of Milford houses still run on the switchboard they were built with. An upgrade replaces old fuses with circuit breakers and RCD protection, and gives the house room for the heat pumps, cooktops and lighting it runs today.

Rows of circuit breakers, digital meters and wiring inside an open distribution board, lit in orange and blue

The boards behind Milford's houses

Milford was built in waves, and the switchboard often tells you which wave a house belongs to. There are bungalows from the 1920s, baches that holidaymakers put up before the Harbour Bridge and later turned into permanent homes, and the houses that group builders such as Reidbuilt and Sunline Homes built in the Milford area through the 1960s and 1970s, once the bridge had opened in 1959. Each generation of house was wired to the standards and the appetite for electricity of its day.

A board that has served one of those houses for fifty years or more may still have rewireable ceramic fuses, no RCD protection at all, and no spare space for another circuit. It may also have been added to by several owners, with a sub-board here and a spare fuse pressed into service there. None of that means it will fail tomorrow, but it does mean it was never designed for a house with two heat pumps, an induction cooktop and a home office on the wish list.

Signs your switchboard is due for an upgrade

Fuses instead of circuit breakers

Ceramic fuse carriers with fuse wire inside them. They worked, but a fuse rewired with heavier wire than it should have no longer protects the cable behind it.

No RCD protection

New lighting and power circuits must now be protected by RCDs at the board. Many older boards have none, so the circuits people use every day lack the RCD protection that cuts the power when current leaks through a person.

No room for another circuit

A new heat pump installation, a kitchen renovation or a workshop often needs a circuit of its own, and a full board has nowhere to put it.

Heat, buzzing or scorch marks

Any of these at the switchboard is a reason to call the same day, not to plan an upgrade for later.

A tired meter box near the sea

BRANZ guidance says PVC-U, fibreglass or stainless steel are the best meter box options in coastal areas. A rusting steel box on a beachfront house is worth replacing while the board is being done; the meter inside is the responsibility of your electricity retailer.

Inspection, certification and paperwork

A switchboard upgrade is not just a swap of parts in a box. The Electrical Workers Registration Board explains that installing a higher capacity board to cope with increased use is an alteration classed as high-risk work, and high-risk work has to be inspected. Moving a board can fall into the same category when it means extending, jointing or rerouting the mains.

Our registered electricians do the work and test it, provide the certification that applies, and arrange the licensed electrical inspector the job needs, so you do not have to find one yourself. Keep the certificates and the inspection record together: they describe the work done on the most important part of your installation, and an insurer or a buyer may ask to see them.

How a switchboard upgrade runs

Look at the whole installation
The existing board, the mains coming in, the earth, and every circuit on the property, plus what you plan to add over the next few years.
Plan the new board
Circuit breakers sized to each circuit, RCDs covering the lighting and power circuits, dedicated circuits where an appliance needs one, and spare space for later.
Changeover
The power is off while the old board comes out and the new one goes in, so plan around the fridge, freezers and anyone who depends on powered medical equipment.
Test, certify and inspect
Every circuit is tested before it is handed back, the certification is completed, and the licensed inspector checks the work that requires inspection.

Switchboard questions

Do I need a new switchboard to add a heat pump?

Not always. A heat pump can sometimes run from an existing circuit with enough spare capacity, but many need a dedicated circuit back to the board, and an old board may have no room for one. We check before you buy the unit, so the electrical side is not a surprise.

What does an RCD actually do?

It watches the current going out on a circuit and coming back, and if some is missing, because it is flowing through a faulty appliance or a person, it switches off almost instantly. Circuit breakers protect the cable from overload; RCDs protect people.

My board has old fuses but nothing has ever gone wrong. Is it unsafe?

Not automatically. The questions are whether the fuses are the right ratings, whether there is any RCD protection, and what condition the wiring behind the board is in. We will tell you honestly whether an upgrade is needed now or can be planned.

Will the switchboard need to move?

Usually it stays where it is. It may be worth moving if it is hidden in a cupboard or awkward to reach, because BRANZ guidance favours a board that is easy to find and reach in an emergency. Moving it can make the job high-risk work that needs inspection.

Can you upgrade the board in an apartment?

Yes, the board inside your own apartment. If the main switch, meters or supply cables are in a shared meter room, that part of the work needs the building manager's or body corporate's agreement, and our commercial electrical page covers how we work in shared buildings.