Generators - wattage power calculator
How to calculate which generator you would need:
Generators are measured by their KVA (kilo volt amps).
To calculate the amps that it can produce divide KVA by 230 volts.
To calculate the wattage it can produce, multiply KVA by 80% if being used for a 3-phase alternator or by 100% for a single phase generator.
e.g. a 6KVA generator single phase:
Amps = 6000/230 = 26amps
Wattage = 6000*100% = 6000
It is important to note that this is the maximum that it can produce but not the rated amount which is normally around 90% of this. In addition to this, all engines are specified at sea level so for a generator working in Johannesburg you would need to multiply by approximately another 82% to compensate for altitude. Therefore your 6 KVA generator in Jhb would be producing about 4,428 Watts.
Below please find a list showing the wattage required by various appliances. It is also shown on the back of most appliances. It is worth noting however that on start-up, electric motors may require up to double their wattage.
The main thing you need to consider is whether your generator is an emergency back-up in which case you don’t need to run all of your appliances e.g. geysers and heaters or whether you want a “seamless” transition from Eskom to generator without turning anything off.
The above calculation sheet is an indication of the common business and household rating of common appliances. This sheet should be used as an indication for the size of the generator that you require and should not be used in isolation. A load test or consultation with an Electrical professional is recommended.
Previous page: Generator questions & answers
Next page: Water, trash, hymech, firefighting pumps
Tel: 2711 230 2600 | Fax: 2711 976 4807 | E.Mail: | Power products site map
Search engine optimised web sites