# Mitsubishi Electric FR-F700PJ Instruction Manual Page 119

Air-conditioning inverter.

Setting of acceleration/deceleration time and acceleration/ deceleration pattern
(2)
Deceleration time setting (Pr. 8, Pr. 20)
 Use Pr. 8 Deceleration time to set the deceleration time required to reach 0Hz from Pr. 20 Acceleration/deceleration reference
frequency.
 Set the deceleration time according to the following formula.
Deceleration
=
Maximum operating frequency - Pr. 10 
time setting
 DC injection brake is not applied until the frequency drops to 0Hz regardless of the Pr.10 setting under IPM motor control. Under IPM motor control, calculate
as Pr.10 ="0."
Example) How to find the setting value for Pr.8 when decreasing the output
frequency from the maximum frequency of 50Hz in 10s with
Pr.20=120Hz and Pr.10=3Hz.
(3)
Set two kinds of acceleration/deceleration times (RT signal, Pr. 44, Pr. 45 )
Pr. 44 and Pr. 45 are valid when the RT signal is ON.
When "9999" is set to Pr. 45, the deceleration time becomes equal to the acceleration time (Pr. 44).
For the RT signal, set "3" in any of Pr. 178 to Pr. 182 (input terminal function selection) to assign the function.
NOTE
 When the acceleration/deceleration pattern is S-pattern acceleration/deceleration A (refer to page 118), the acceleration/
deceleration time is the time required to reach Pr. 3 Base frequency. When the S-pattern acceleration/deceleration A is
set under IPM motor control, acceleration/deceleration time is the time to reach the rated motor frequency (Refer to
page 86).
 Acceleration/deceleration time formula when the set frequency is the base frequency or higher
4
t=
9
 Guideline for acceleration/deceleration time at the Pr. 3 Base frequency of 60Hz (0Hz to set frequency)
 Changing terminal assignment may affect the other functions. Set parameters after confirming the function of each
terminal.
114
Pr. 20
T
5
2
 f
T
+
2
9
(Pr. 3)
Frequency setting (Hz)
Acceleration/
deceleration time (s)
5
15
Deceleration time from maximum operating frequency to stop
T: Acceleration/deceleration time setting (s)
f: Set frequency (Hz)
60
5
15
120Hz
 10s
Pr. 8 =
50Hz-3Hz
120
200
400
12
27
102
35
82
305
25.5s  