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IEC61000-3? IEC61000-3
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ANUAL
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VPN 98-025/7
Voltech Instruments
The problem that this may cause can be seen in the situation where several
appliances are connected to the ‘same’ ac source (say within a building)
and one of the appliances is presenting a fluctuating load to the supply.
The ac supply must have a certain amount of source impedance between
the generator and distribution point (i.e. the building), and therefore the
fluctuating current taken by one appliance will produce a fluctuating
voltage drop across this source impedance, resulting in a fluctuating source
voltage being presented to the other appliances connected to the same
distribution point.
Of crucial importance is the effect caused by the changing supply voltage
in the light output of a filament lamp. This output is proportional to the
square of the source voltage, and therefore even small changes of voltage
can cause significant changes in light intensity. The effect on a human
observer of this variation of light output is known as flicker.
IEC61000-3-2 specifies separately the limits for the harmonic amplitudes
of the current taken by a fluctuating load. It also specifies two tests for the
voltage disturbance produced by load currents flowing in a given source
impedance: a maximum voltage deviation test and a flicker test; these
should be applied to all equipment.
Summary of Contents for PM3000ACE
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