If you require assistance with this Power Calculator or what generator will best suit your requirements, do not hesitate to contact us.
Guide to units:
|Kilo Volt Amps|
|Ampere or Current|
Generator Size to Start Motors
Instructions: Fill in the HP of the motor(s) in their starting sequence, select the start method (DOL - Direct On Line or Star Delta) and press Calculate. The required generator size will then be displayed at the bottom.
* Please NOTE the above calculations are an estimate only because other factors such as site conditions, motor efficiencies and iron losses are not taken into consideration.
For a more detailed answer and qualified advice, please give us a call on 1800 833 800
|Appliance||Rated Watts||Rated kVA||Rated kVA|
|(Appliances)||(To operate appliance)||( To start appliance)|
|Air Conditioner (Evaporative model)||275-1000||0.34-1.25||1.36-5|
|Air Conditioner (Reverse cycle)||200-2500||0.25-3.13||1-12.5|
|Domestic Water Pumps||275-1000||0.34-1.25||1.36-5|
|Kettle or jug||1600-3000||2-3.75||2-3.75|
|Welder 140A||5000||6.25||8 min|
Inductive loads (typically electric motors, electric pumps, electric compressors and air conditioners) require 6-8 times more current to start than to run. Most generators can provide 100% overload for start up purposes. A 1 Hp electric motor therefore will require 3-4kVA for start up. Once the 1 Hp electric motor has started, it will only consume 1 kVA leaving a extra 2-3kVA available for other appliances.
However, the newer 'Inverter' style generators may be more efficient and capable of starting higher loads.
The generator size must be equal or greater than the total consumption of all applications. The higher starting requirement must be taken into account accordingly. To maximise the generator potential, the largest electrical motor should be started on its own and further appliances should only be switched on thereafter.