63
When momentary power loss time is longer than the minimum
baseblock time, speed search operation is started immediately
after power recovery.
Momentary power
loss time
Min.
baseblock time
Inverter baseblock
time
Momentary power
loss time
Min.
baseblock time
Inverter baseblock
time
When min. baseblock
time is longer than
momentary power loss
time.
When min. baseblock
time is shorter than
momentary power loss
time.
To ensure that a fault such as OC does not occur during speed
search operation, V/f must be reduced during speed search opera-
tion, as compared with that during normal operation. Set V/f during
speed search as follows by the set value of No. 56:
V/f during speed search = V/f at normal operation x No. 56
2-8-26 Accel/Decel Prohibit Function
Item name
Constant to be set
Factory preset
Accel/Decel Prohibit Function
No. 32 and No. 33
No. 32 = 1, No. 33 = 3
When an accel/decel prohibit command is input during accelera-
tion or deceleration, the output frequency is maintained and accel-
eration or deceleration is stopped as long as the input is being
received.
If a stop command is received while the accel/decel prohibit com-
mand is being received, the accel/decel prohibit command will be
overridden and operation will be stopped.
The accel/decel prohibit command can be input from multifunction
contact input terminals 4 and 5. Set the value of constant No. 32 to
8 to specify an accel/decel prohibit command for terminal 4, and
set the value of constant No. 33 to 6 to specify an accel/decel pro-
hibit command for terminal 5.
The following time chart shows the operation of the accel/decel
prohibit command:
FWD RUN
ACCEL/DECEL
PROHIBIT Command
Frequency
Reference
Frequency Agreed
Signal
Output
Frequency
V/f During Speed
Search (No. 56)
Description of Functions and Constants
Section 2-8
