Before choosing a generator, you need to know 
 
Maximum power and rated power 
 
The power of a generated indicated in advertising is generally the maximum power that the manufacturer can produce. However, you can also see the indicated rated power. 
 
Maximum power= the maximum power output that the generator can produce, which normally can only lasts for 30 minutes. 
 
Rated power= the power under which the generator can work continuously, and it is normally 90% of the maximum power. 
 
Normally, please decide whether the generator is suitable for you according to the rated power. 
 
Starting instantaneous power and normal operating power 
 
Some appliances need extra power when starting. But others do not need extra power when starting and their starting power is just the same as their normally operating power. 
 
To correctly calculate the power you need, you need to know the following two different loads: 
 
Resistance-type load: 
The resistance-type load is very simple and its starting power is the same as the normally operating power. Resistance-type load includes: 
• Bulb
• Coffee machine 
• Toaster 
 
Reactance-type load: 
 
Reactance-type load has one starting engine that needs more power to start. But after it is in normal operation, it needs far less power. In special circumstances, the starting power is 3 times of the normally operating power.  Reactance-type load includes: 
• Fridge/compressor
• Stove/ fan 
• Water pump
• Air conditioner
• Power tools 
 
Part of the reactance-type engines do not only needs extra power when starting, but also needs extra power when at the beginning of their operation. For example, when the electric saw starts to cut trees, the power needed increases. 
 
Generator selection for household uses 
 
• For the water well and water pump, they normally need a 240V generator with high power (3800W or above). 
• The natural gas heater needs lower power and it is about 2500 W; the electric heater at least needs more than 4500 W. 
 
The power for household uses usually ranges from 3000 W to 6500 W.
 
Selection of generators for outdoors activities 
• It mainly depends on what power you need for you equipment.
• In normal conditions, the power of 1000W-2000W can meet most needs. 
 
Selection of generators for industrial purposes :
The power for industrial purposes is more extensive and the power needed depends on the tool type you use. Please refer to Common Electric Appliances Power Reference to help you for a rapid assessment. The simple method is to choose the tools you use and add the power needed. 
 
Please do remember that the tools at the beginning of operation, or the electric appliance with an engine need higher starting power than in normal operating.
 
Meanwhile, please read Optimal Selection Guide of Generator Power to help you to use a smaller generator that can meet your requirement.