Basic System Description - Hitachi WJ200 Series Instruction Manual

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Basic System Description

A motor control system will obviously include a motor and inverter, as well as a circuit
breaker or fuses for safety. If you are connecting a motor to the inverter on a test bench
just to get started, that's all you may need for now. But a system can also have a
variety of additional components. Some can be for noise suppression, while others may
enhance the inverter's braking performance. The figure and table below show a system
with all the optional components you might need in your finished application.
From power supply
Breaker,
MCCB or
GFI
L1 L2 L3
+1
Inverter
+
GND
T1 T2 T3
Motor
Thermal
switch
NOTE: Note that some components are required for regulatory agency compliance (see
chapter 5 and Appendix D).
Name
Breaker / A molded-case circuit breaker (MCCB), ground fault
disconnect
interrupter (GFI), or a fused disconnect device. NOTE:
The installer must refer to the NEC and local codes to
ensure safety and compliance.
Input-side This is useful in suppressing harmonics induced on the
AC Reactor
power supply lines and for improving the power factor.
WARNING: Some applications must use an input-side
AC Reactor to prevent inverter damage. See Warning
on next page.
Radio noise Electrical noise interference may occur on nearby
filter
equipment such as a radio receiver. This magnetic
choke filter helps reduce radiated noise (can also be
used on output).
EMC filter (for Reduces the conducted noise on the power supply
CE applications,
wiring between the inverter and the power distribution
see Appendix D)
system. Connect to the inverter primary (input) side.
Radio noise
This capacitive filter reduces radiated noise from the
filter (use in
main power wires in the inverter input side.
non-CE
applications)
DC link choke Suppress harmonics generated by the inverter.
However, it will not protect the input diode bridge
rectifier.
Radio noise Electrical noise interference may occur on nearby
filter
equipment such as a radio receiver. This magnetic
choke filter helps reduce radiated noise (can also be
used on input).
Output-side
This reactor reduces the vibration in the motor caused
AC Reactor
by the inverter's switching waveforms, by smoothing
the waveform to approximate commercial power quality.
It is also useful to reduce harmonics when wiring from
the inverter to the motor is more than 10m in length.
LCR filter Sine wave shaping filter for output side.
Function