Choosing the right Generator for your needs

Generators fall into 2 basic groups

Leisure and Home use

Industrial/Site use

There are certain key features that you will need your Generator to have when selecting a product for either of these groups.

Leisure and Home use.
This is a generator that will typically be used either in camping, caravan, small exhibition situations and around the home and office. Key features required will include silent or quiet running, weight and size, ease of transportation, run time, 230volt and 12volt output and maybe Inverter technology*

Industrial/Site use.
This is a product that will typically be used in the work place or on site where the output is restricted to 110volt. Key features again can also be silent or quiet running, ease of transportation, low oil warning systems, three phase supply, petrol or diesel powered, run time and very importantly robustness.

Inverter Technology*
If you are powering a TV, computer or other appliances requiring stable voltage and frequency output then it is advised that you choose a generator featuring Inverter technology* We suggest you check with the generator manufacturer.

Calculate Total Power Output Required.
Once you have decided the type of generator that best meets your needs you then need to calculate the power output that you require depending on the appliances that you intend to use. This task may seem a little daunting but is actually quite simple. The following 4 steps will help you achieve this.

A. Identify the tools and appliances that you will power from the Generator

B. Determine the required wattage for each item.

C. Total the wattage required to power your identified items simultaneously. (Allowing extra for motor starting). However, if you have an appliance with a high wattage but will not be used continuously this can be considered in your calculation. (Example) When in your caravan, turn your lights and TV off when you need to use the microwave!!

D. Choose a Generator that has continuous rated watts that meets or exceeds this total.

Wattage Table.
To help you identify the wattage of the tools and appliances that you need to power from the Generator please use this table. However, please note that the watt’s shown are only an average recommendation, therefore please check your items before use.



Fluorescent Lamp 35w
Light Bulb 40/60/100w
Control Heating Pump 100w
Palm Sander 175w
Radio / Hi-Fi 200w
Slow Cooker  
Colour TV* 250w
VCR* 300w
Printer 350w
String Trimmer  
Bench Grinder 400w
13mm Drill  
Orbital Sander 450w
Floor Lamp 500w
Hedge Trimmer  
4" Angle Grinder 550w
1/3 HP Airless Sprayer 600w
13mm Hammer Drill  
Deep Freezer** 700w
Hammer Drill  



5" Circular Saw 750w
5" Angle Grinder 1000w
Lawn mower 10" Hover  
Belt Sander 1050w
Vacuum Cleaner 1100w
Coffee Maker 1200w
Steam Iron 1250w
Cement Mixer 1320w
10-16" Chain Saw 1500w
600w Microwave  
Hot Air Gun  
Portable Heater  
Photocopier 1600w
8" Floor Sander 2000w
Air Compressor** 2200w
12" Grinder 2500w
Fan Heater 3000w
Arc Welder -130A** 3500w
1HP Pressure Washer  
Washing Machine 4000w


Motor Starting is an important consideration when buying a Generator. Keep in mind that induction-type motors, like those that run sump pumps, refrigerators and compressors typically require 2-3 times their listed running watts to start. Below is a chart you can use to determine how many watts you will need to start up motors of various sizes and types.

Note: Power tools using universal commutator motors do not require additional startup power.

Starter Chart

Motor Size


Watts Required To Start Motor

1/8 HP 275w 850w
1/6 HP 275w 850w
1/4 HP 400w 1050w
1/3 HP 450w 1350w
1/2 HP 600w 1800w
3/4 HP 850w 2600w
1 HP 1110w 3300w
2 HP 2200w 6600w

Convert kVA to watts

For DC application: 2.0 kVA = 2.0 kW or 2000 watts.

For AC equipment, it depends on the power factor (PF)

kVA x PF = kW.

kW x 1000 = watts.

Resistance type loads have a power factor near 1.00, so 2.0 kVA = 2.0 kW or 2000 watts.

Motors may have a power factor closer to 0.85.

In that case 2.0 kVA x 0.85 = 1.7 kW or 1700 watts.