Chapter 7 Optional Accessories |CFP2000 Series
7-8
AC Output Reactor
If the length of cable between AC motor drive and motor is too long, it may make AC motor drive
trigger protection mechanism for GF (Ground Fault), OV (Over Current) and the AC motor drive stops
running. The cause is the over long motor cable will generate extremely large stray capacitance,
make common mode current of 3-phase output get too large and then trigger GF protection
mechanism; OC protection is triggered which is caused by stray capacitance of cable-cable and
cable-ground are getting larger, and its surge current makes AC motor drive output over large current.
To prevent from the common mode current that stray capacitance generates, set up AC output reactor
between AC motor drive and motor to increase the high frequency impedance.
Power transistor is switched via PWM to control the output voltage and frequency for AC motor drive.
During the switch process, impulse voltage (dv/dt) rises and falls rapidly will make inner voltage of
motor distribute unequally, and then the isolation of motor will be getting worse, and have interference
of bearing current and electromagnet. Especially when AC motor drive and motor are connected by
long leading wire, the influence of damping of high frequency resonance and reflected voltage that
caused by cable spreading parameters is getting large, and it will generate twice incoming voltage at
motor side to be over voltage, destroy the isolation.
Installation
An AC input reactor is installed in series with the mains power to the three input phases R S T as
shown below:
Connecting an AC output reactor
Specifications of AC output reactors (standard items)
The table below shows the specifications of AC output reactors (standard items).
380V~460V/ 50~60Hz
Type KW HP
Rated Amps of
AC Reactor(Arms)
Max. continuous
Amps (Arms)
3%
impedance(mH)
5%
impedance(mH)
Built-in
DC reactor
3% Input AC reactor
Delta part # (Note 2)
Normal
Duty
Light
Duty
Normal
Duty
Light
Duty
Normal
Duty
Light
Duty
Normal
Duty
Light
Duty
Normal Duty Light Duty
007 0.75 1
2.8 3 4.48 3.6 8.102 8.102 13.502 13.502 X N/A N/A
015 1.5 2
3 4.2 4.8 5.04 8.102 6.077 13.502 10.127 X N/A N/A
022 2.2 3
4 5.5 6.4 6.6 6.077 4.050 10.127 6.752 X N/A N/A
037 3.7 5
6 8.5 9.6 10.2 4.050 2.700 6.752 4.501 X N/A N/A
040 4 5
9 10.5 14.4 12.6 2.700 2.315 4.501 3.858 X N/A N/A
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