Chapter 2 Installation And Wiring; Inverter Wiring - Hitachi P1-00080-L Basic Manual

Chapter 2

2.4 Inverter Wiring

Applicable peripheral equipment
Power
supply
<1>
<2>
<3>
<4>
<5>
<6>
<7>
R S T
PD
<8>
INV
P
<9>
R0
RB
N
T0
<10>
U V W
<11>
<12>
<13>
<14>
M
Motor
Notes:
• The description of peripheral equipment is for Hitachi 3-phase, 4-pole squirrel-cage motor.
• Select breakers with proper interrupting capacity. (Use inverter-ready breakers)
• Use earth-leakage circuit breakers (ELB or MCB) to ensure safety.
• Use copper electric wire (HIV cable) with allowable temperature rating 75°C or more.
• If the power line exceeds 20 m, use cable with mayor wire size for the power line.
• Tighten each terminal screw with the specified tightening torque.
Loose terminal screws may cause short circuits and fire.
Excessive tightening torque may cause damage to the terminal block or inverter body.
• When selecting a rated sensitivity current for earth-leakage circuit breaker, use a
separated breaker considering a total cable length of between Inverter-Power supply and
Inverter–Motor distance. Do not use a high-speed type of earth-leakage circuit breaker.
Use a delayed-type circuit breaker, because the high-speed type may malfunction.
• When using a CV cable for wiring through a metal conduit, the average current leakage
would be 30mA/km.
• When using a high relative dielectric constant cable such as IV cable, the leakage current is
about eight times as high as the standard cable. Therefore, when using an IV cable, use
ELCB with rated sensitivity current by eight times given in the table below. If the total cable
length exceeds 100 m, use a CV cable.
•Do not pull the power line cable after wiring. Doing so may cause screw loosening.
No. Name
<1> Electric wire
<2> Earth-leakage circuit breaker ELCB or
MCCB
<3> Magnetic contactor MC
<4> Input AC reactor
(For harmonic control, power supply
coordination, and power
correction)
<5> Noise filter for inverter
<6> Radio noise filter
(Zero-phase reactor)
<7> Radio noise filter on the input side
(Capacitor filter)
<8> DC Choke
<9> Braking resistor
<10> Regenerative braking unit
<11> Noise filter on the output side
<12> Radio noise filter
(Zero-phase reactor)
<13> Output AC reactor
For reducing vibrations and
preventing thermal relay
malfunction
<14> LCR filter
Total cable length
See "Recommended cable gauges, wiring accessories, and crimp
terminals" on Page 2-9.
Use input reactor for harmonic wave control, or when power supply
voltage imbalance exceeds 3% or more, or when the power supply
factor capacity is over 500 kVA or more, or when the power voltage may
change rapidly. This reactor also improves the power factor.
This noise filter reduces the conductive noise that is generated by
the inverter and transmitted in cables. Connect this noise filter to
the primary side (input side) of the inverter.
The inverter may generate radio noise through power supply wiring
during operation.
Use this noise filter to reduce the radio noise (radiant noise).
Use this noise filter to reduce the radiant noise radiated from input
cables.
Use DC chokes to reduce the harmonic generated by the inverter.
Use these devices to increase the braking torque of the inverter for
operation in which the inverter turns the connected load on and off
very frequently or decelerates the load running with a high moment
of inertia.
Connect this noise filter between the inverter and motor to reduce
the radiant noise radiated from cables for the purpose of reducing
the electromagnetic interference with radio and television reception
and preventing malfunctions of measuring equipment and sensors.
Use this noise filter to reduce the noise generated on the output
side of the inverter. (This noise filter can be used on both the input
and output sides.)
Inverter driven motor may cause large vibrations compared to
commercial power supply direct start motor.
Connect Output AC reactor between inverter and motor to lessen
the pulsation of motor. Also, connect output AC reactor, when the
cable length between inverter and motor is longer (10 m or more),
to prevent thermal relay malfunction due to the harmonic waves
generated by switching operation of inverter. Note that the thermal
relay can be replaced with a current sensor to avoid the
malfunction.
Connect this noise filter between the inverter and motor to convert
the inverter output into a sinusoidal waveform and to reduce the
motor vibration, motor noise and the radiant noise radiated from
cables. Surge voltage can be also controlled.
2-6
Installation and Wiring
Sensitivity current (mA)
100 m or less 50
300 m or less 100
Function