Switching To Commercial Power Supply (Commercial Power Supply Change) - Hitachi WJ Series User Manual

Chapter 9
9.7.9

Switching to Commercial Power Supply (Commercial Power Supply Change)

 How to use the inverter to start a motor and then use a commercial power supply for continuous
Q
operation?
 How to switch between a commercial power supply and the inverter for driving the motor?
 A commercial power supply change function is available for systems with a large moment of
A
inertia of the motor load. This feature allows the use of the inverter to drive acceleration and
deceleration, and a commercial power supply to drive the motor at constant speeds.
 When "Commercial power supply change [CS] (14)" is turned on with the RUN command on, the
inverter output is shut off and the motor starts free run. When [CS] terminal is turned off while
on, the inverter matches the command frequency to the motor rotation speed (Active frequency
matching restart at the frequency of the previous output interruption.) after the "Retry wait time
after instantaneous power failure/undervoltage error [b003]" has elapsed.
 The [CS] terminal behaves in the same way as when the [FRS] terminal is turned on/off with
!
"Restart mode after FRS release [b088]" as the "Active frequency matching restart (02)" and
"Active frequency matching restart speed selection [b030]" as the "Output frequency at shut
down (02)". For details, refer to "9.7.4 Starting with Active Frequency Matching".
Code
[C001]
Input terminal
to
function
[C007]
◼ Example of connection diagram and timing chart for commercial power supply switching
 For FWY, RVY, and CSY, use a low voltage relay.
 Apply a mechanical interlock between MC3 and MC2. Otherwise, the inverter may be damaged.
 The electrical leakage breaker ELCB tripping due to a ground fault, or some other reason, will
also render the commercial power circuit inoperable. If a backup is required, connect a separate
commercial power circuit to MC2.
3-phase
AC power
supply
MC1
MC2
MC3
ON
FW
ON
CS
Inverter output
Operation
frequency
Item
Commercial power supply change [CS]:
This function is used when switching to a commercial
power supply. When [CS] is turned on, inverter output is
shut-off.
NFB ELCB
FWY
RVY
CSY
ON
ON
Interlock time between
MC2 and MC3 (0.5 to 1 s)
ON
Description
MC2
MC3
MC1
R U
S V
T
W
Inverter
FW
RV
CS
L
Interlock time between MC2 and
MC3 (0.5 to 1 s)
MC1
MC2
MC3
FW
CS
Inverter output
frequency
Active frequency matching restart
9-7-15
Inverter Functions
THR
M
ON
Interlock time between
MC1 and CS (0.5 to 1 s)
ON
ON
ON
Retry wait time
Operation
Data
14