MITSUBISHI ELECTRIC FR-S520 - Manual (Page 101)

92
CAUTION
•
The cumulative number in Pr. 69 is incremented by "1" when retry operation is
regarded as successful, i.e. when normal operation is continued without the
protective function (major fault) activated during a period four times longer than
the time set in Pr. 68.
•
If the protective function (major fault) is activated consecutively within a period four
times longer than the above waiting time, the control panel may show data different
from the most recent data or the parameter unit (FR-PU04) may show data different
from the first retry data. The data stored as the error reset for retry is only that of the
protective function (major fault) which was activated the first time.
•
When an inverter alarm is reset by the retry function at the retry time, the stored
data of the electronic overcurrent protection, etc. are not cleared. (Different from
the power-on reset.)
CAUTION
When you have selected the retry function, stay away from the motor and
machine unless required. They will start suddenly (after the reset time has
elapsed) after occurrence of an alarm.
When you have selected the retry function, apply in easily visible places the
CAUTION seals supplied to the instruction manual (basic).
2
.10.2 PWM carrier frequency
You can change the motor sound.
Parameter Name
Factory
Setting
Setting
Range
Remarks
70 Soft-PWM setting 1 0, 1
72
PWM frequency
selection
1 0 to 15
Setting is enabled when
Pr. 30 = "1"
REMARKS
By parameter setting, you can select Soft-PWM control which changes the motor
tone.
Soft-PWM control changes motor noise from a metallic tone into an unoffending
complex tone.
<Setting>
Parameter
Number
Setting Description
0 Soft-PWM invalid
70
1 When any of "0 to 5" is set in Pr. 72, Soft-PWM is made valid.
72 0 to 15
PWM carrier frequency can be changed.
The setting displayed is in [kHz].
Note that 0 indicates 0.7kHz and 15 indicates 14.5kHz.
REMARKS
An increased PWM frequency will decrease motor noise but noise and leakage
current will increase. Take proper action (Refer to pages 18).
Metallic sound may be generated from the motor at sudden deceleration but it is not a
fault.