Mitsubishi FR-A846-00023, Инструкция по эксплуатации

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Power supply harmonics
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PRECAUTIONS FOR USE OF THE INVERTER
3.2
Power supply harmonics
3.2.1
Power supply harmonics
The inverter may generate power supply harmonics from its converter circuit to affect the power generator, power factor
correction capacitor etc. Power supply harmonics are different from noise and leakage currents in source, frequency band and
transmission path. Take the following countermeasure suppression techniques.
• The differences between harmonics and noises
• Countermeasures
The harmonic current generated from the inverter to the input side differs according to various conditions such as the wiring
impedance, whether a reactor is used or not, and output frequency and output current on the load side. (A DC reactor is built
in to the FR-A806.)
For the output frequency and output current, we understand that this should be calculated in the conditions under the rated
load at the maximum operating frequency.
NOTE
• The power factor improving capacitor and surge suppressor on the inverter output side may be overheated or damaged by
the harmonic components of the inverter output. Also, since an excessive current flows in the inverter to activate overcurrent
protection, do not provide a capacitor and surge suppressor on the inverter output side when the motor is driven by the
inverter. For power factor improvement, install a reactor on the inverter input side.
Item Harmonics Noise
Frequency
Normally 40th to 50th degrees or less (3
kHz or less).
High frequency (several 10 kHz to 1 GHz order).
Location To-electric channel, power impedance. To-space, distance, wiring path
Quantitative understanding Theoretical calculation possible. Random occurrence, quantitative grasping difficult.
Generated amount Nearly proportional to the load capacity.
Changes with the current variation ratio. (Gets larger as
switching speed increases.)
Affected equipment immunity Specified by standards per equipment. Different depending on maker's equipment specifications.
Countermeasure Provide an AC reactor. Increase distance.
AC reactor
(FR-HAL)
Do not insert power
factor improving capacitor.
MCCB MC
Inverter
Power supply
R
S
T Z
Y
X
U
V
W
R/L1
S/L2
T/L3
M