How to select the right generator in South Africa

Published: 20-Jun-2018

Residential generators are available in a variety of sizes. Eskom warns that generator under-sizing is one of the most common mistakes made by buyers.

What should you power with the generator?

The first thing you need to do is to decide what you need to power when the power is out. This will determine how large a generator you need to power these devices. The following chart provides a summary of generator power output and the types of electronics that could be powered with a generator of that size.


Generator Size in Watts Capable Electrical Devices
3,500 watts Heater, small air conditioner, fan, television, small refrigerator, light bulbs, microwave, coffee maker, toaster
7,000 watts Small to medium central air conditioner, washing machine, stove, freezer, air compressor, saws, grinders
10,000 watts Large central air conditioner, clothes dryer, electric water heater

How big a generator should you get?

Not all devices can be run simultaneously, and some devices create an extra load when first started which will pull additional wattage from the generator.

All heating appliances – such as stoves, heaters, dishwashers, geysers, kettles, tumble dryers, toasters and hairdryers – draw the most power, and should be switched off.

PCs and electronic equipment don’t use much power but are voltage sensitive. If the generator does not deliver a constant voltage and there are dips and spikes, equipment may suffer damage.

The following chart provides some examples of common household items and their individual wattage consumption.

Device Watts Device Watts
Light bulb 60 Microwave 750
Fan 75 Coffee maker 850
Radio 100 Furnace 1,000
Small TV 300 Vacuum cleaner 1,000
Computer 500 Toaster 1,500
Garage door opener 600 Air compressor 2,000
Refrigerator 700 Freezer 2,500
Dishwashed 700 Central air 5,000

By selecting which devices are to be run at the same time, a 7KW generator can power most household devices on an alternating basis. A 3,5KW generator can handle a small apartment and most recreational activities, and a 10KW generator can provide alternative power for a house or small business in the event of an extended power outage.

Eskom has published a document titled “Selecting the right type of generator”, providing guidelines on which generators to buy, and how to connect them to your home.

Of course, the easiest thing to do would be to contact Extra Mile Electrical for advice and assistance with choosing the right generator for your home or business.

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Other useful links: Electrical Contractors in Gauteng; Residential Electrical Services in Gauteng ; Commercial Electrical Services in Gauteng; Industrial Electrical Services in Gauteng; Leading Electrical Company in Gauteng

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