SJ700-2 Instruction Manual NT204DX - Hitachi America, Ltd.

Chapter 4 Explanation of Functions
4.2.8 Acceleration/deceleration time setting
- Specify a longer time for slower acceleration or deceleration;
specify a shorter time for quicker acceleration or deceleration.
- The time set with this function is the time to accelerate (or
decelerate) the motor from 0 Hz to the maximum frequency (or
vice versa).
- If you assign the LAD cancellation (LAC) function to an
intelligent input terminal and turns on the terminal, the set
acceleration/deceleration time will be ignored, and the output frequency will immediately follow the
frequency-setting command.
- To switch the acceleration and deceleration time among the 1st, 2nd, and 3rd settings, assign function
"08" (SET) and "17" (SET3) to intelligent input terminals (see Section 4.2.38). Use the SET and SET3
signals for switching.
- As the Accel/decel time input selection by P031, select one of the (1) input from the digital operation, (2)
input from option board 1, (3) input from option board 2, and (4) input from the easy sequence program.
Item Function code Range of data Description
Acceleration (1) time F002/F202/
Set the length of time to accelerate the motor from 0
0.01 to 3600.(s)
setting
F302
Hz to the maximum frequency.
Deceleration (1) time F003/F203/
0.01 to 3600.(s)
setting
F303
Accel/decel time input
selection
P031
Related code
F002/F202/F302: Acceleration (1) time setting,
1st/2nd/3rd motors
F003/F203/F303: Deceleration (1) time setting,
1st/2nd/3rd motors
A004/A204/A304: Maximum frequency setting,
1st/2nd/3rd motors
P031: Accel/decel time input selection
C001 to C008: Terminal [1] to [8] functions
Set the length of time to decelerate the motor from
the maximum frequency to 0 Hz.
00 Input from the digital operator (OPE)
01 Input from option board 1 (OP1)
02 Input from option board 1 (OP2)
03 Input from the easy sequence program (PRG)
Terminal function C001 to C008 46 LAD cancellation
Output frequency
Maximum frequency
A004/A204/A304
Set output frequency
Actual
acceleration
time
F002/F202/F302
Actual
deceleration
time
F003/F203/F303
The actual time to accelerate/decelerate the motor will be no less than the minimum
acceleration/deceleration time that depends on the inertial effect (J) due to the mechanical system and
motor torque. If you set a time shorter than the minimum acceleration/deceleration time, the inverter may
trip because of overcurrent or overvoltage.
Acceleration time (ts)
(J
t s = L +J M )×N M
9.55×(T s -T L )
Deceleration time (t B )
(J
t B = L +J M )×N M
9.55×(T B +T L )
J L : Inertia effect (J) of the load converted to that of the motor shaft (kg-m 2 )
J M : Inertia effect (J) of the motor (kg-m 2 )
N M : Motor speed (rpm)
Ts: Maximum acceleration torque driven by the inverter (N-m)
T B : Maximum deceleration torque driven by the inverter (N-m)
T L : Required running torque (N-m)
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