Backlash Measures (Pr.29 = "3", Pr.140 To Pr.143); Variable-Torque Acceleration/Deceleration (Pr.290 = "6") - Mitsubishi Electric FR-F800 Instruction Manual

(F) Setting of acceleration/deceleration time and acceleration/deceleration pattern
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.290 = "6")
• This function is suitable to accelerate/decelerate a variable torque load such as a fan and blower in a 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 frequency page 497
Pr.7 Acceleration time, Pr.8 Deceleration time, Pr.20 Acceleration/deceleration reference frequency
Pr.10 DC injection brake operation frequency
Pr.178 to Pr.182 (input terminal function selection)
Pr. 142
Time
Time
Pr.8
Deceleration time
page 502
page 329
page 187
PARAMETERS
5
GROUP
F
193