12
Wiring
2.3.6 Connecting the 24V external power supply
CC-Link communication between the master module and the inverter can be continued while the main power circuit is OFF if
the 24V external power supply is connected across terminals +24 and SD. When the main circuit power supply is turned ON,
the power supply changes from the 24V external power supply to the main circuit power supply.
(1) Specification of the applied 24V external power supply
y Input voltage 23.5 to 26.5VDC
y Input current 0.7A or less
(2) Confirming the 24V external power supply
y "EV" flickers in the monitor display on the operation panel while the 24V external power is being supplied. The 24V
external power supply operation signal (EV) is also output. For the EV signal, assign the function to the terminal Y0 or
a virtual terminal of CC-Link communication by setting "68 (positive logic) or 168 (negative logic)" in Pr. 190 to Pr. 192 or
Pr. 313 to Pr. 315 (Output terminal function selection).
(3) Function of the 24V external power supply operation
y When the main power supply is turned ON during the 24V external power supply operation, a reset is performed in the
inverter, then the power supply changes to the main circuit power supply. During the reset operation in the inverter, the
inverter cannot be controlled through the CC-Link communication.
y The operation stops when the power supply changes to the 24V external power supply from the main circuit power
supply regardless of the operating status (in a stop, in running, in automatic restart after instantaneous power failure,
in offline tuning, in main circuit capacitor life measurement).
y All start signals (STF signal, STR signal, and on the operation panel) are invalid during the 24V external power
supply operation.
y Faults history and parameters can be read and parameters can be written (when the parameter write from the
operation panel is enabled) using the operation panel keys.
y The safety stop function is also valid during the 24V external power supply operation. When the safety stop function is
active, however, "SA" is not displayed because "EV" is displayed. The "EV" display has priority over the "SA" display.
y The following items can be monitored during the 24V external power supply operation:
Frequency setting, output current peak value
∗, converter output voltage peak value∗, cumulative energization time,
actual operation time
∗, cumulative power∗, PID set point, PID measured value, PID deviation, and cumulative power 2∗
(dedicated to CC-Link communication)
∗ The monitored data is not updated after the power supply is changed from the main circuit power supply.
(Refer to Chapter 5 of the Instruction Manual (Applied) for the details of each monitor.)
y The valid signals when the 24V external power supply is ON are EV, SAFE, SAFE2, Y90, Y91, Y95, REM, LF, and
ALM. (Other signals are OFF.)
(Refer to Chapter 5 of the Instruction Manual (Applied) for the detail of each signal.)
y The alarms, which have occurred when the main circuit power supply is ON, continue to be output after the power
supply is changed to the 24V external power supply. Perform the inverter reset to reset the alarms.
y The retry function is invalid for all alarms when the 24V external power supply is ON.
y If the power supply changes from the main circuit power supply to the 24V external power supply while measuring the
main circuit capacitor's life, the measurement completes after the power supply changes back to the main circuit
power supply (Pr.259 = "3").
NOTE
y When the 24V external power supply is input while the main circuit power supply is OFF, the CC-Link communication
is enabled, but the inverter operation is disabled.
y Inrush current higher than the value described in (1) may flow at a power-ON. Confirm that the power supply and
other devices are not affected by the inrush current and the voltage drop caused by it.
y When the wiring length between the external power supply and the inverter is long, the voltage often drops. Select the
appropriate wiring size and length to keep the voltage in the rated input voltage range.
y
In a serial connection of several inverters, the current increases when it flows through the inverter wiring near the power
supply. The increase of the current causes voltage to drop further. When connecting different inverters to different power
supplies, use the inverters after confirming that the input voltage of each inverter is within the rated input voltage range.
y
"E.SAF" may appear when the start-up time of the 24V power supply is too long in the 24V external power supply operation.
Flickering