Ac Reactors (Acrs) - Fuji Electric FRENIC-HVAC User Manual

4.4.1.2

AC reactors (ACRs)

An ACR is effectively used when the power supply is unstabilized (excessive interphase voltage
unbalance) or in DC link bus operation (shared PN operation) requiring stable DC power. It is also
used for power supply matching and for correction of voltage waveform and input power factor. AC
reactors cannot be used with the 575V class series.
For power supply matching
• Use an ACR when there are thyristor-driven loads or phase-advancing capacitors are being turned
ON/OFF.
xx
Voltage
MCCB or MCCB or MCCB or
RCD/ RCD/ RCD/
ELCB ELCB ELCB
AC reactor
MC
(ACR)
Capacitor for
Inverter Thyristor
correction of input
converter
power factor
(a) Connection example
• Use an ACR when the interphase voltage unbalance ratio of the inverter power supply exceeds 2%.
Interphase
Figure 4.6 External View of AC Reactor (ACR) and Connection Example
Voltage depression
(b) Voltage depression example
caused by thyristor converter
voltage unbalance ( %) =
MCCB or
RCD/ELCB *
* With overcurrent protection
Voltage
Time
Phase-advancing
capacitor ON
(c) Voltage fluctuation example when a
phase-advancing capacitor is applied
Max. voltage ( V) - Min. voltage
Three - phase average voltage
AC reactor Magnetic contactor
(MC)
(ACR)
X U
Y V
Z W
4-36
Time
( V)
× 67
( V)
Inverter
T1 L1
L1/R
T2 L2
L2/S
T3 L3
L3/T