Mitsubishi Electric FR-F700PJ Series Manual page 34

7, 8, 20, 44, 45, 791, 792
Acceleration/deceleration time setting
Pr.7 Acceleration time
Pr.20 Acceleration/deceleration reference frequency
Pr.44 Second acceleration/deceleration time
Pr.791 Acceleration time in low-speed range
Pr.792 Deceleration time in low-speed range
Used to set motor acceleration/deceleration time.
Set a larger value for a slower speed increase/decrease or a
smaller value for a faster speed increase/decrease.
 Use Pr. 7 Acceleration time to set the acceleration time required to
reach Pr. 20 Acceleration/deceleration reference frequency from 0Hz.
 Use Pr. 8 Deceleration time to set the deceleration time required to
stop from the Pr. 20 Acceleration/deceleration reference frequency.
Pr. 20
(60Hz)
Acceleration time
Pr. 7, Pr. 44

If torque is required in the low-speed range (rated motor frequency/
10) under IPM motor control, set the Pr.791 Acceleration time in low-
speed range and Pr.792 Deceleration time in low-speed range settings
higher than the Pr.7 Acceleration time and Pr.8 Deceleration time
settings so that the slow acceleration/deceleration is performed in
the low-speed range. (Refer to page 81 for the rated motor
frequency.)
Acceleration time
in low-speed range
Slope set by Pr. 791
Acceleration time
Slope set by Pr.7
9, 51, 561
Motor protection from overheat
(electronic thermal relay function,
PTC thermistor protection)
Pr.9 Electronic thermal O/L relay
Pr.51 Second electronic thermal O/L relay
Pr.561 PTC thermistor protection level
Set the current of the electronic overcurrent protection to protect
the motor from overheat. This feature provides the optimum
protective characteristics, including reduced motor cooling
capability, at low speed.

This function detects the overload (overheat) of the motor, stops the
operation of the inverter's output transistor, and stops the output.

Set the rated current [A] of the motor in Pr.9.
(If the General-purpose motor has both 50Hz and 60Hz ratings and
the Pr.3 Base frequency is set to 60Hz, set the 1.1 times of the 60Hz
rated motor current.)

When using a motor with an external thermal relay, etc., set "0" in
Pr.9 to make the electronic thermal relay function invalid. (Note that
the output transistor protection of the inverter (E.THT) functions.)
 When using a Mitsubishi constant-torque motor
1) Set "1" or "13", "50", "53" in any of Pr. 71. (This provides a 100%
continuous torque characteristic in the low-speed range.
2) Set the rated current of the motor in Pr. 9.

When the RT signal is ON in a General-purpose motor operation, thermal
protection is provided based on the
Use this function when rotating two motors of different rated currents
individually by a single inverter. (When rotating two motors together, use
external thermal relays.)
34
When setting parameters, refer to the instruction manual (applied) and understand instructions.
Pr.8 Deceleration time
Pr.45 Second deceleration time
IPM IPM IPM
IPM IPM IPM
Running
frequency
Time
Deceleration time
Pr. 8, Pr. 45
Low-speed range
(rated motor frequency/10)
Time
Deceleration time
in low-speed range
Deceleration time Slope set by Pr.792
Slope set by Pr.8
GP GP GP
V/F V/F V/F MFVC MFVC MFVC
Pr. 51
setting.

When the motor has a built-in PTC thermistor, the output can be
input to the terminal 2 and terminal 10. When the input from the PTC
thermistor reaches the resistance setting in Pr.561 PTC thermistor
protection level, the PTC thermal error signal (E.PTC) is output and
the inverter trips.
10 to 12
DC injection brake of General-purpose
motor control
V/F V/F V/F
Pr.10 DC injection brake operation frequency
Pr.12 DC injection brake operation voltage
The DC injection brake can be operated at a motor stop to adjust the
stop timing and braking torque.
Pr. 10
Operation frequency
Time
Pr. 12
DC injection
Operation
brake voltage
voltage
Time
Pr. 11
Operation time
10, 11
DC injection brake of IPM motor control
Pr.10 DC injection brake operation frequency
At a motor stop, DC injection brake operates to apply braking
torque to the motor.
Operation example when DC injection
brake is exercised (Pr. 11
0)
DC injection brake
(Hz)
is exercised at 0Hz.
Time
DC injection Time DC injection
brake
Pr. 11 Operation time
13, 571
Starting frequency
Pr.13 Starting frequency
You can set the starting frequency and hold the set starting
frequency for a certain period of time.
Set these functions when you need the starting torque or want
smooth motor drive at a start.
Output
frequency (Hz)
60
Setting
range
Pr. 13
0
Pr. 571 setting time
STF
GP GP GP
MFVC MFVC MFVC
Pr.11 DC injection brake operation time
When
Using the
Pr.12 Initial
Mitsubishi
Constant
Value
Torque
Motor
3.7K or
4% 
lower
5.5K, 7.5K 4% 2%
11K, 15K 2% 
 If the Pr. 71 initial value is
changed to the setting for use
with a constant-torque motor, the
Pr. 12 setting changes to the
corresponding value in the above
table.
IPM IPM IPM
Pr.11 DC injection brake operation time
Operation example when DC injection
brake is not exercised (Pr. 11 = 0)
Pr. 10
(Hz)
Coasting frequency time
Time
Motor coasting
Time
brake
GP GP GP
V/F V/F V/F
MFVC MFVC MFVC
Pr.571 Holding time at a start
Time
ON