Load shedding and your fridge: how to protect your food and your compressor

Anyone living in South Africa knows the routine. The lights go out, the kettle goes cold and your first thought is the fridge. Power cuts, whether scheduled or sudden, are hard on food and can also shorten the life of your fridge and freezer if you are not careful. The good news is that a few simple habits make a big difference.

How long does food stay safe?

The general food safety guidance is that an unopened fridge keeps food cold enough for about four hours. A full, unopened freezer holds its temperature for roughly 48 hours, and a half-full one for around 24. These are rough numbers. They depend on how full the unit is, how warm your kitchen is and how well the doors seal.

• Keep the doors closed. Every opening lets cold air out and warm air in.
• A full freezer stays cold much longer than a half-empty one, because frozen items act like ice blocks.
• Chest freezers hold cold better than uprights, because cold air is heavy and stays inside when you lift the lid.
• Discard perishable food such as meat, dairy, eggs and cooked leftovers that have been above 5 degrees Celsius for more than about four hours.
• Food in the freezer that still has ice crystals on it, or feels as cold as if it were in a fridge, can generally be refrozen, though the quality may suffer.

Prepare before the outage

• Fill empty space in the freezer with bottles of frozen water. They stabilise the temperature and give you ice for a cooler.
• Keep a spare cooler box and ice packs ready for essential items.
• Put a cheap fridge thermometer on the middle shelf so you know what temperature the food has reached.
• Group food together in the freezer. A tightly packed freezer holds its cold better.

Why power coming back can hurt your compressor

The moment the power returns is where fridges are most at risk. When a compressor stops, the refrigerant pressures inside the sealed system are still high on one side. If power returns and the compressor tries to start straight away against that pressure, it draws a huge starting current and may stall, trip the overload or burn out the start relay. Many modern fridges have a built-in delay of a few minutes. Older ones do not.

Power returns can also come with surges and spikes, which damage control boards, especially on newer inverter fridges that have sensitive electronics.

Protecting the fridge

• Use a surge protector with a built-in time delay made for fridges and freezers. It holds the power back for a few minutes after the supply returns and blocks spikes.
• If there is no protector, unplug the fridge at the wall during outages and plug it back in a few minutes after the power has stabilised.
• If you use an inverter or a UPS, check that it is rated for the starting surge of the compressor, which can be several times the running current. A pure sine wave inverter is kinder to compressors and electronic boards than a modified sine wave unit.
• Do not keep switching the fridge on and off repeatedly. Wait a few minutes between restart attempts.

Signs the outage damaged your fridge

After a power event, watch for a fridge that runs constantly, does not reach its normal temperature, clicks and stops, or does not start at all. Display panels that stay blank, error codes on the display or a fridge that keeps resetting often mean a board or sensor has been damaged by a surge. These faults are easier and cheaper to fix when addressed quickly.

For businesses

If you run a restaurant, shop or bakery, a power cut has legal and food safety consequences. Keep a temperature record, know your backup plan, and discard food that has been out of temperature for too long. A properly sized generator or inverter, wired in by a qualified electrician, protects both your stock and your equipment. Ask us if you need to know how much power your compressors need to restart.

If your fridge or freezer is not behaving after a power cut, give us a call. We repair household and commercial refrigeration across Durban and surrounding suburbs, and we will tell you plainly whether it is a quick fix or a bigger problem.