Hitachi SJ700-2 instruction manual Acceleration/deceleration time setting, Deceleration time tB

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

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/	0.01 to 3600.(s)	Set the length of time to accelerate the motor from 0
setting	F302		Hz to the maximum frequency.
Deceleration (1) time	F003/F203/	0.01 to 3600.(s)	Set the length of time to decelerate the motor from
setting	F303		the maximum frequency to 0 Hz.
Accel/decel time input		00	Input from the digital operator (OPE)
	P031	01	Input from option board 1 (OP1)
selection		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	Actual
acceleration	deceleration
time	time
F002/F202/F302	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)

ts＝ (JL＋JM)×NM 9.55×(Ts－TL)

Deceleration time (tB)

tB＝ (JL＋JM)×NM 9.55×(TB+TL)

JL: Inertia effect (J) of the load converted to that of the motor shaft (kg-m2)

JM: Inertia effect (J) of the motor (kg-m2)

NM: Motor speed (rpm)

Ts: Maximum acceleration torque driven by the inverter (N-m)

TB: Maximum deceleration torque driven by the inverter (N-m)

TL: Required running torque (N-m)

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