Shortest Acceleraiton/Deceleration And Optimum Acceleration/Deceleration (Automatic Acceleration/Deceleration) (Pr. 61 To Pr. 63, Pr. 292, Pr. 293) - Mitsubishi Electric FR-B-750 to 75K Instruction Manual

Setting of acceleration/deceleration time
and acceleration/deceleration pattern
4.8.4 Shortest acceleraiton/deceleration and optimum acceleration/deceleration
(automatic acceleration/deceleration) (Pr. 61 to Pr. 63, Pr. 292, Pr. 293)
Setting can be made only for FR-B3 series.
The inverter operates in the same conditions as when appropriate values are set in each parameter even if
acceleration/deceleration time and V/F pattern are not set. This function is useful when you just want to operate,
etc. without fine parameter setting.
Parameter
Name
Number
61 Reference current
Reference value
62
at acceleration
Reference value
63
at deceleration
Automatic
292 acceleration/
deceleration
Acceleration/
deceleration
293 individual
operation
selection
(1) Shortest acceleration/deceleration mode (Pr. 292 = "1, 11", Pr. 293)
⋅ Set when you want to accelerate/decelerate the motor for the shortest time. It is desired to make acceleration/
deceleration in a shorter time for a machine tool etc. but the design values of machine constants are unknown.
⋅ Acceleration/deceleration speed is automatically adjusted at a start of acceleration/deceleration so that
acceleration/deceleration is made with the maximum torque the inverter can output according to the setting value
of Pr. 7 Acceleration time and Pr. 8 Deceleration time. (The setting values of Pr. 7 and Pr. 8 are not changed)
⋅ Either acceleration or deceleration can be made in the shortest time using Pr. 293 Acceleration/deceleration individual
operation selection.
When the setting value is "0" (initial value), both acceleration and deceleration can be made in the shortest time.
⋅ Since the 7.5K or less inverter has a built-in brake resistor, set Pr. 292 to "11". Set "11" also when a high-duty brake
resistor or brake unit is connected. Deceleration time can be further shortened.
⋅ When the shortest acceleration/deceleration mode is selected, the stall prevention operation level during
acceleration/deceleration becomes 150% (adjustable using Pr. 61 to Pr. 63 ). The setting of Pr. 22 Stall prevention
operation level and stall level by analog input are used only during a constant speed operation.
⋅ It is inappropriate to use for the following applications.
a)Machine with a large inertia such as a fan (more than 10 times). Since stall prevention operation will be
activated for a long time, this type of machine may be brought to an alarm stop due to motor overloading, etc. .
b)It is desired to always perform operation with a constant acceleration/deceleration time.
c)It is desired to perform operation making sure the inverter and motor have enough capability.
REMARKS
⋅ If outmatic acceleration/deceleration mode has been selected, inputting the jog signal (jog operation), RT signal (second
function selection) or X9 signal (third function selection) during an inverter stop will switch to the normal operation and give
priority to jog operation, second function selection or third function selection. Note that JOG and RT signal input is invalid even
if JOG signal and RT signal are input during operation in automatic acceleration/deceleration mode.
⋅ Since acceleration/deceleration is made with the stall prevention operation being activated, the acceleration/deceleration speed
always varies according to the load conditions.
⋅ Note that when proper values are set in Pr. 7 and Pr. 8 , acceleration/deceleration time may be shorter than selecting shortest
acceleration/deceleration mode.
94
Initial
Setting Range
Value
0 to 500A
9999
9999
0 to 220%
9999
9999
0 to 220%
9999
9999
0
1
0 11
3
7, 8
0
0 1
2
Description
Set the reference current during shortest/ optimum
acceleration/deceleration.
Rated inverter output current value is reference
Set the limit value/optimum value during shortest/
optimum acceleration.
Shortest acceleration/deceleration: 150% is a limit value
Optimum acceleration/deceleration: 100% is an
optimum value
Set the limit value/optimum value during shortest/
optimum deceleration.
Shortest acceleration/deceleration: 150% is a limit value
Optimum acceleration/deceleration: 100% is an
optimum value
Normal mode
Shortest acceleration/deceleration (without brake)
Shortest acceleration/deceleration (with brake)
Optimum acceleration/deceleration
Brake sequence mode 1, 2 (Refer to page 108.)
Both acceleration and deceleration are made in the
shortest/optimum acceleration/deceleration mode
Only acceleration is made in the shortest/optimum
acceleration/deceleration mode
Only deceleration is made in the shortest/optimum
acceleration/deceleration mode
B3 B3 B3