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Power consumption of an electric circular saw, planer, disk grinder or the like may be higher depending on the
load. In order to deliver the full performance, it is necessary to estimate 1.5 to 2 times greater power
consumption.
(2) When the motor output of the electrical equipment is known
Some electrical equipment is not indicated with the current and the power consumption but the motor output.
In such cases, the generator can be used when the sum of the "necessary output of the generator (VA)"
obtained from the following formula is less than the rated AC output of the generator (VA).
Because a general electrical equipment is not indicated with the power factor, "0.8" is used in the case of an
electric power tool and "0.5" in the case of a general-purpose motor for the above rough calculation.
3800 VA
5000 VA
6000 VA
Generator
Rated AC output
E 43
E 60
E 71
Generally, the following values are used though efficiency varies depending on the types of motors.
Motor output of the electrical equipment (W)
Efficiency x Power factor
Necessary output of the generator (VA) =
6-2. Starting Current
The current required from starting the above electrical equipment to operating in steady state is larger than the
current or the power required during "operation" of the electrical equipment. This is called "starting current".
There is no problem if no load is applied to an electric power tool equipped with a commutator motor from the
start. However, there may be a case that an electric power tool equipped with an induction motor (especially the
starting current of a split-phase induction motor is about three times larger than the current during operation)
cannot be started.
0.6
Electrical equipment
Power factor
General-purpose motors
(Induction motors)
Electric power tools
(Commutator motors)
0.9
Summary of Contents for E 71
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