Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE - Manual (Page 130)

5-6 SMC Dialog Plus Controller Special Application Considerations
Power Factor Capacitors The controller may be installed on a system with power facto
correction capacitors. These capacitors must be installed on the lin
side to prevent damage to the SCRs in the SMC Dialog Plus
controller (Se Figure 5.3).
Figure 5.3 Power Factor Capacitors
High values of inrush current and oscillating voltages are common
when capacitors are switched. Therefore, additional impedance
should be connected in series with the capacitor bank to limit th
inrush current and dampen oscillations. The preferred practice is to
insert air-core inductors as shown in Figure 5.4.
The inductors can be simply constructed:
• for volts greater than or equal to 460V: use a six inch diameter
coil with eight loops
• for volts less than 460V: use a six inch diameter coil with six
loops
The wire should be sized to carry the steady-state current that will
flow through the capacitor bank during normal operations.
The coils should be mounted on insulated supports away from metal
parts. This will minimize the possibility of producing heating effects.
Do not mount the coils to be stacked directly on top of each other.
This will increase the chances of canceling the effectiveness of the
inductors.
Power Input
3-Phase
Branch Protection ➀
Power Factor
Correction Capacitors ➀
SMC Dialog Plus Controller ➁
L1/1
L2/3
L3/5
T1/2
T2/4
T3/6
Motor
➀
➀
➁ Customer supplied
Overload protection is included as
standard feature of the SMC Dialog Plus controller.