12 | Westinghouse Portable Power
OPERATION
POWER OUTPUT AND DEMAND
The generator should not be run completely unloaded for extended periods otherwise the engine may be damaged. It
is recommended that the generator should always be operated with at least one-third of its rated 120-Volt AC power
output. 120-Volt AC devices have two different electric power demands that must be taken into consideration, namely
the running power and the starting/peak power. Both are measured in Watts (typically abbreviated as “W”).
The steady state continuous load is the running power demand and this is often marked on the device near its model number
or serial number. Sometimes the device might only be marked with its voltage (i.e. 120 V) and current draw (e.g. 6 Amp or 6 A),
in which case the running power demand in Watts can be obtained by multiplying the voltage times the current, e.g. 120 V ×
20 A = 2,400 W.
Simple resistive 120-Volt AC devices such as incandescent bulbs, toasters, heaters, etc. have no extra power demand when
starting, and so their starting power demands are the same as their running power demands.
More complex120-Volt AC devices containing inductive or capacitive elements such as electric motors have a momentary
extra power demand when starting, which can be up to seven times the running power demand or more. Manufacturers of
such devices rarely publish this starting power demand and so it’s often necessary to estimate it. A rule of thumb for devices
fitted with an electric motor is to apply a starting power multiplier of 1.2 for small hand-held or portable devices and a value
of 3.5 for larger stationary devices. For example, a 900 W angle grinder can be assumed to have a starting power demand
of at least 1.2 × 900 W, which equals 1,080 W. Similarly, a 1,650 W air compressor can be assumed to have a starting power
demand of at least 3.5 × 1,650 W, which equals 5,775 W.
To prevent overloading of the generator’s 120-Volt AC system:
1. Add up the running power demand of all the 120-Volt AC devices that will be connected to the generator at one time. This
total must not be greater than the generator’s specified running power output.
2. Add up the running power demand again, but for the largest motor-driven device use the value of its starting power
demand instead of its running power demand. This total must not be greater than the generator’s specified starting power
output.
3. The total running power demand of all the devices that will be connected to any one of the generator’s outlets must not
exceed the generator’s specified running power output or 3,700 W, whichever is the lesser.
TRANSPORTING THE GENERATOR
The generator should be stopped and both the fuel control switch and fuel cap vent should be turned to the OFF
position before transporting the generator. Keep the unit level during transport to minimize the possibility of fuel leakage
or, if possible, drain out the fuel prior to transport.
If the generator has been operating, allow the unit to cool down before loading it onto the transport vehicle.