Delta CT2000 Series User Manual page 62

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.
Method of set up
AC output reactor sets up between motor and U, V, W which are at output side of AC motor drive in
series-connected way. See the figure below:
Specifications of AC output reactors (standard item)
The following table shows the specifications of AC output reactors (standard items) and the
part numbers of reactors (optional). Since high frequency occurs from the output will make huge
iron loss, input and output reactors cannot use mutually.
380V~460V/ 50~60Hz
Model HP
VFD750CT43F00A6 100
VFD900CT43F00A8 120
VFD110CT43F00B 15
VFD150CT43F00B 20
VFD185CT43F00B 25
Power input
AC output reactor setup
Max. continuous
Rated Amps
Amps
(Arms)
(Apeak)
Light Heavy Light
Duty Duty Duty
144 105 318
180 143 382
24 17 41
32 23 54
38 30 64
Chapter 7 Optional AccessoriesCT2000 Series
AC r eactor
(output)
3% reactor
(mH)
Heavy Light Heavy
Duty Duty Duty
223 0.162 0.221
303 0.135 0.162
36 0.881 1.174
49 0.66 0.881
64 0.639 0.66
7-9
Motor
5% reactor
input reactor Delta
Built-in
(mH)
DC
Light Heavy reactor Light
Duty Duty Duty
0.270 0.34
O
0.225 0.25
O
1.468 2.07
X
1.100 1.53
X
1.065 1.17
X
3%
part#
Heavy
Duty
N/A N/A
N/A N/A
N/A N/A
N/A N/A
N/A N/A