Power Output And Demand - Westinghouse iGen4500s Instruction Manual

Figure 24 - Type "A" USB Male Plug

Power Output and Demand

There are two limits to the amount of electric power
that the generator can usefully provide: (a) its total
240-Volt AC, 12-Volt DC or 5-Volt DC electric power
generating capacity or power output and (b) the
electric current or power output capacity of each
individual 240-Volt AC, 12-Volt DC or 5-Volt DC
outlet.
The generator's total power output measured in
Watts is listed in the Specifications. Two 240-Volt
AC power outputs are specified for the generator,
namely the running power and the starting power.
The 12-Volt DC and 5-Volt DC power outputs are
also specified.
NOTICE
DO NOT overload the generator's 240-Volt AC,
12-Volt DC or 5-Volt DC circuits beyond their
rated capacities. This can result in damage to the
generator or to the connected devices.
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 240-Volt AC power output.
240-Volt AC devices have two different electric
power demands that must be taken into
consideration, namely the running power and the
starting 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. 240 Volt or 240 V) and current draw
(e.g. 6 Ampere or 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. 240 V
× 6 A = 1,440 W.
Simple resistive 240-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.
OPERA TION
More complex 240-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 240-Volt
AC system:
1. Add up the running power demand of all the
240-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
3,600 W, whichever is the lesser.
The above guidelines serve as approximations
only of determining the running and starting power
demands of 240-Volt AC devices. If in doubt, always
err on the conservative side to avoid overloading
the generator. In the absence of any power demand
information whatsoever, one can assume that any
device fitted with a standard domestic 10 A plug has
a maximum running power demand of 2,400 W (i.e.
240 V x 10 A = 2,400 W). Similarly, a device fitted
with a heavy duty 15 A plug can be assumed to
have a maximum running power demand of 3,600 W
(i.e. 240 V x 15 A = 3,600 W). And then apply the
appropriate multiplying factor for starting power
demand if the device has an electric motor.
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