Defined below are some common terms to get familiar with and an appliance chart to better understand what size generator you will need for your power requirements.
Rated / Continuous Output – is the power that a generator can produce for long periods of time. This corresponds to an appliances Running Load Requirement as defined below.
Maximum Output – is the maximum output that a generator can produce. Maximum power is usually available for a very brief period to cater for start-up wattage of appliances. This corresponds to an appliances Starting
Load Requirement as defined below.
What is a Running Load Requirement?
Running load requirements are simply a total of all the eletrical loads to be operated simultaneously. This is stated on the appliance specifications or can be based on actual measurements if a clamp-on probe type AC Current Meter
is available. Any electrician should be able to assist you with this exercise. Some appliances may not list the wattage on the nameplate, but may show the rated current in amps and voltage. The wattage can estimated by multiplying
these together to get the watts. So the formula is Watts = volts x amps
What is a Starting Load Requirement?
This is the power your appliance will take on start-up and needs to be calculated and researched. Determining the starting load requirements can be a bit more complicated. Certain electrical devices require additional power and
current when initially turned on. An example of this is an electric motor because the rotor of the motor and the shaft driven load (fan, pump, compressor, saw, etc.) is initially at a standstill. It requires more energy to
accelerate these rotating parts to operating speed than it does to keep them rotating. Therefore, during the period of acceleration, the demand on the power supply is greater. To precisely evaluate the motor starting capability the
detailed motor characteristics need to be known.
In the following appliance chart, we have aimed at simplifying this for easier understanding. The values on this list are given as an average, and can change from case to case.