3-26
same time with the speed search command. A typical operation sequence is
shown below.
Ry1
Ry2
Ry1
Speed search command
RWD/REV run command
3. When the speed search and DC injection braking are set, set the Min.
baseblock time (Cn-37). For the Min. baseblock time, set the time long
enough to allow the motor’s residual voltage to dissipate. If an overcurrent is
detected when starting a speed search or DC injection braking, raise the
setting Cn-37 to prevent a fault from occurring. As a result, the Cn-37 setting
cannot be set too small.
(35)
Low Voltage Alarm Detection Level (Cn-39)
•
In most cases, the default setting Cn-39 need not be changed. If an external AC
reactor is used, decrease the low voltage alarm detection level by adjusting Cn-39
setting smaller. Be sure to set a main-circuit DC voltage so that a main circuit
undervoltage is detected.
(36)
Slip Compensation Primary Delay Time
(Cn-40)
•
In most cases, the setting Cn-40 need not be changed. If the motor speed is not
stable, increase the Cn-40 setting. If the speed response is slow, decrease the setting
of Cn-40.
(37)
S-curve Characteristic Time at Acceleration Start (Cn-41)
(38)
S-curve Characteristic Time at Acceleration End (Cn-42)
(39)
S-curve Characteristic Time at Deceleration Start (Cn-43)
(40)
S-curve Characteristic Time at Deceleration End (Cn-44)
•
Using the S-curve characteristic function for acceleration and deceleration can
reduce shock to the machinery when stopping and starting. With the inverter, S-
curve characteristic time can be set respectively for beginning acceleration, ending
acceleration, beginning deceleration and ending deceleration. The relation between
these parameters is shown in
Fig. 27
.