6-25
IM CW500-01EN
6.7
Power Quality
Press QUALITY.
Factors That Degrade Power Quality and Symptoms
Event
Waveform
Symptoms
Adverse Effects
Harmonics
The device control circuit
uses an inverter (capacitor
input full-wave rectifier) and
thyristor (phase-control)
circuits.
These circuits cause
current distortion, which
generates harmonics.
Harmonic currents can
cause phase advance
capacitor and reactor
burnouts, transformer
buzz, circuit breaker
malfunction, flicker in TV
images, and noises in
audio devices.
Voltage
swell
RMS
Inrush current occur when the
power line switch is turned on
causing the voltage to increase
temporarily.
Equipment, robots,
and other machines
may shut down,
or PCs and office
appliances may be
reset.
Voltage
dip
RMS
Inrush current occurs when
motors and other loads are
applied causing the current to
dip.
Voltage
interruption
RMS
Lightning and other electric
surges interrupt the power
supply.