Here’s something most homeowners never think about: the most dangerous moment in a power outage isn’t the blackout itself. It’s the instant the lights come back on.
When the grid is re-energised after an unplanned interruption, an inrush of current surges through the network. Heating appliances and devices left switched on draw this load, but with this come fluctuations in the voltage and strain on the grid. These can result in a secondary failure and loss of power in the grid or switching transients that can damage sensitive electronic equipment. Both create problems for the homeowner as they may result in additional downtime or administration headaches and costs.
The South African Weather Service’s seasonal forecast for June to October 2026 points to above-normal rainfall along the eastern coastal areas, while cold temperatures across the interior are set to drive a sharp spike in demand for geysers, panel heaters and underfloor heating systems. As households crank up the heat, increased energy usage will cost more, while also placing greater strain on the electrical grid, which can create stress points and cause failures in the system, leading to temporary service interruptions and increasing the chances of damage to the electrical devices in the home.
The season also brings its own hazards. Strong cold fronts bring damaging winds, lightning strikes and heavy rain that regularly knock out power infrastructure. Cable theft typically intensifies during the season too, as criminals target copper infrastructure during longer, darker nights, leading to more frequent and unpredictable outages.
“Winter is the toughest season for any home electrical installation,” says Dr Andrew Dickson, engineering executive at CBi-electric: low voltage. “Higher heating loads, severe weather and a less stable grid all stack up at once. The good news is that a few straightforward precautions can dramatically reduce the risk of damage.”
Here are four ways to keep your installation safe through the cold months:
- Start with surge protection
The first line of defence against switching transients is a surge protection device (SPD) installed at the distribution board. An SPD clamps voltage spikes before they travel through the household circuit, protecting the electrical installation as well as appliances and sensitive electronic devices throughout the home.
“Many homeowners have SPDs fitted to individual appliances or extension cords, but that only addresses part of the risk,” Dr Dickson notes. “Protection installed at the DB board provides a co-ordinated protection plan and intercepts a surge at the entry point before it can propagate.”
Verify with a qualified electrician that your DB board SPD is correctly rated for the installation and that it is in good working order, generally indicated by an LED or flag. If it has protected the installation from a previous surge event and is no longer able to provide the installation with protection, then the unit should be replaced to ensure that the best possible protection is available.
- Test your earth leakage protection; don’t assume it works
Earth leakage protection units (ELPUs) are required under South African regulations and are designed to trip within milliseconds of detecting a fault, protecting occupants from electrocution. But the test button on the unit exists for a reason.
“An earth leakage is an electronic device and therefore susceptible to switching transients in the network. Checking the effective operation of your earth leakage regularly is critically important to ensure the safety of all members of the household,” Dr Dickson warns. “The test is straightforward: press the button, confirm the circuit trips, reset. If it doesn’t trip, the unit needs to be replaced. Any ELPU that fails to respond correctly should be treated as faulty until assessed by a registered electrician. It is important to replace these units immediately as it leaves the installation unprotected and therefore a risk for electrocution.”
- Don’t overload your circuits
A single high-draw appliance such as a geyser, an underfloor heating system, or a panel heater places significant load on a circuit. Running multiple devices simultaneously on the same circuit or using extension cords to power appliances beyond the circuit’s design capacity creates a risk of overheating at connection points, nuisance tripping, or, in worst cases, electrical fires.
“The convenience of extension cords makes it easy to underestimate the cumulative draw on a circuit,” Dr Dickson explains. “Homeowners often don’t think about the total load; they think appliance by appliance. The majority of plug circuits are designed to operate at a maximum of 16 A and, therefore, by using multiplugs and extension cords coupled to large loads, can result in failure of components in the electrical system leading to significant losses.”
Use dedicated circuits for high-draw appliances where possible, avoid daisy-chaining extension cords and always ensure that the extension cord is fully unwound, and never use an extension cord as a permanent wiring solution.
- Let smart energy management share the load
Beyond protective hardware, smart energy management systems can reduce unnecessary strain on an installation by automating when and how heating appliances draw power. Timer-controlled geysers, for instance, can be programmed to heat water during off-peak periods rather than cycling continuously, while smart plugs and home energy monitors can surface real-time consumption data that helps homeowners identify overloaded circuits before they become a problem.
When homeowners can see exactly what their installation is carrying at any given moment, they’re better placed to make decisions that protect both their appliances and the people in the home. In addition, this visibility can be used to control what is spent on energy during a month.
“Winter is predictable,” concludes Dr Dickson. “The conditions that strain electrical systems, such as cold snaps, storms, outages, and heavy heating loads, are with us right now and will only intensify. A bit of attention now saves you the emergency call-out later.”
