Starting Frequency And Start-Time Hold Function - Mitsubishi Electric 800 Series Instruction Manual

8.4

Starting frequency and start-time hold function

V/F V/F V/F Magnetic flux Sensorless Sensorless Sensorless
Magnetic flux Magnetic flux
It is possible to set the starting frequency and hold the set starting frequency for a certain period of time.
Set these functions when a starting torque is needed or the motor drive at start needs smoothing.
Pr. Name
13
Starting frequency
F102
571
Holding time at a start
F103
 Starting frequency setting (Pr.13)
• The frequency at start can be set in the range of 0 to 60 Hz.
• Set the starting frequency at which the start signal is turned ON.
Output
frequency
(Hz)
60
Pr.13
0
STF ON
NOTE
• The inverter does not start if the frequency setting signal has a value lower than that of Pr.13.
For example, while Pr.13 = 5 Hz, the inverter output starts when the frequency setting signal reaches 5 Hz.
 Start-time hold function (Pr.571)
• This function holds during the period set in Pr.571 and the output frequency set in Pr.13 Starting frequency.
• This function performs initial excitation to smooth the motor drive at a start.
Output
frequency
(Hz)
60
Pr.13
0
Pr. 571 setting time
STF ON
NOTE
• When Pr.13 = 0 Hz, the starting frequency is held at 0.01 Hz.
• When the start signal was turned OFF during start-time hold, deceleration is started at that point.
• At switching between forward rotation and reverse rotation, the starting frequency is valid but the start-time hold function is
disabled.
CAUTION
• Note that when Pr.13 is set to a value equal to or lower than the setting of Pr.2 Minimum frequency, simply turning ON
the start signal runs the motor at the frequency set in Pr.2 even if the command frequency is not given.
Parameters referred to
Pr.2 Minimum frequencypage 211
Initial value Setting range
0.5 Hz 0 to 60 Hz
0 to 10 s
9999
9999
Time
Time
Description
Set the starting frequency at which the start signal is turned
ON.
Set the holding time of the frequency set in Pr.13.
The holding function at start is disabled.
8. (F) Settings for Acceleration/Deceleration
8.4 Starting frequency and start-time hold function
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