Partial power loss: common causes

Partial power loss is confusing. The kitchen lights work but the bedrooms are dark. The fridge is running but the lounge power points are dead. Or everything seems a bit dim and odd. There are a handful of common causes, and some are simple while others need an electrician quickly.

Start at the switchboard

Most homes split their wiring into separate circuits for lights, power points and big appliances. If one circuit trips, only part of the house goes off. Open the switchboard cover and look for:

• A safety switch in the off position.
• A circuit breaker that has dropped down or sits halfway.
• A blown fuse on an older ceramic fuse board.

If you find one, unplug appliances on that part of the house and try resetting it once. If it holds, plug things back in one by one to see if a single appliance trips it.

Common causes inside the home

A faulty appliance

Kettles, toasters, heaters, fridges and washing machines can develop faults that trip a safety switch. The circuit goes off, taking every outlet on it with it. Unplugging and testing appliances is often all it takes to find the culprit.

Water in an outdoor fitting

An outdoor power point, garden light or sensor light with water inside can trip the circuit it shares with indoor rooms. This is a common cause after rain in coastal suburbs.

A loose connection

A loose connection at a power point, junction or light fitting can cut power to everything downstream on that circuit without tripping anything. Often the first outlet in the chain is the problem.

An overloaded circuit

Running a heater, air conditioner and a few other loads on one circuit can trip the breaker repeatedly, especially in winter.

When it is not inside the house

Loss of one phase

Some homes are supplied with three-phase power, with the house circuits spread across the phases. If one phase is lost on the network or at the service connection, part of the house goes dark while the rest keeps working. Neighbours may report similar issues.

A neutral fault

A failing neutral connection on the supply side can cause strange symptoms: lights dimming or brightening as appliances switch on, some appliances working weakly, or tingles from taps. This is dangerous. If you notice tingles from taps or metal fittings, or lights behaving erratically across the house, stop using appliances and call Endeavour Energy and an electrician straight away.

What you can safely do

• Check the switchboard for tripped devices, as long as there is no smell, heat or damage.
• Unplug appliances on the affected area and try one reset.
• Note which rooms and appliances are affected.
• Ask neighbours if they have any issues.

What you should not do is open up power points, remove light fittings or try to trace wiring yourself. That is licensed electrical work.

How an electrician tracks it down

Kalani uses test equipment to check each circuit, measure insulation resistance and narrow down where the fault sits. Our guide to electrical fault finding explains the process in more detail. Customers have told us he fixed problems that other electricians could not resolve, often by working through the system methodically rather than guessing.

Older homes and repeat problems

If partial outages keep happening, the underlying issue may be an old, overloaded switchboard or ageing wiring. Homes from the 1950s to 70s around Corrimal, Kanahooka and Barrack Point often have boards with few circuits and limited protection. A switchboard upgrade spreads loads more sensibly and adds safety switches to every circuit.

Get help

If part of your home has lost power and you cannot restore it safely, Flowstate offers 24 hour emergency call outs. Call or text Kalani on 0424 400 346, and send a photo of your switchboard if you can.