NOTE
• When the RT signal turns ON during acceleration or deceleration with the S-pattern acceleration/deceleration B enabled, a
pattern of acceleration or deceleration changes to linear at the moment.
Backlash measures (Pr.29 = "3", Pr.140 to Pr.143)
• Reduction gears have an engagement gap and have a dead zone between forward rotation and reverse rotation. This dead
zone is called backlash, and this gap disables a mechanical system from following motor rotation. More specifically, a
motor shaft develops excessive torque when the direction of rotation changes or when constant-speed operation shifts to
deceleration, resulting in a sudden motor current increase or regenerative status.
• To avoid backlash, acceleration/deceleration is temporarily stopped. Set the acceleration/deceleration stopping frequency
and time in Pr.140 to Pr.143.
[Anti-backlash measure
function]
Pr. 140
Pr. 13
Pr. 141
Pr. 143
NOTE
• Setting the backlash measures increases the acceleration/deceleration time by the stopping time.
Variable-torque acceleration/deceleration (Pr.29 = "6")
• This function is useful for variable-torque load such as a fan and blower to accelerate/decelerate in short time.
Linear acceleration/deceleration is performed in the area where the output frequency > base frequency.
[Variable-torque acceleration/deceleration]
Output frequency
Set frequency
Pr.3 Base frequency
Pr.7
Acceleration time
NOTE
• When the base frequency is out of the range 45 to 65 Hz, the linear acceleration/deceleration is performed even if Pr.29 = "6".
• Even if Pr.14 Load pattern selection = "1 (variable torque load)", variable torque acceleration/deceleration setting is
prioritized and the inverter operates as Pr.14 = "0 (constant torque load)".
• For the variable torque acceleration/deceleration time setting, set the time period to reach Pr.3 Base frequency. (Not the time
period to reach Pr.20 Acceleration/deceleration reference frequency.)
• The variable torque acceleration/deceleration is disabled during PM motor control. (Linear acceleration/deceleration is
performed.)
Parameters referred to
Pr.3 Base
frequencypage 528
Pr.7 Acceleration time, Pr.8 Deceleration time, Pr.20 Acceleration/deceleration reference
Pr.10 DC injection brake operation
Pr.14 Load pattern
selectionpage 530
Pr.178 to Pr.189 (Input terminal function
Pr. 142
Time
Time
Pr.8
Deceleration time
frequencypage 535
selection)page 355
5.5 (F) Setting of acceleration/deceleration time and acceleration/deceleration pattern
frequencypage 216
1
2
3
4
5
6
7
8
9
10
221
5. PARAMETERS