PWM carrier frequency automatic reduction function (Pr.260)
• Setting Pr.260 = "1 (initial value)" will enable the PWM carrier frequency auto-reduction function. If a heavy load is
continuously applied while the inverter carrier frequency is set to 3 kHz or higher (Pr.72 ≥ "3"), the carrier frequency is
automatically reduced to prevent occurrence of the Inverter overload trip (electronic thermal relay function) (E.THT). The
carrier frequency is reduced to as low as 2 kHz. Motor noise increases, but not to the point of failure.
• When the carrier frequency automatic reduction function is used, operation with the carrier frequency set to 3 kHz or higher
(Pr.72 ≥ 3) automatically reduces the carrier frequency for heavy-load operation as shown below.
Pr.260
Pr.570 setting
setting
1
0 (SLD), 1 (LD)
0 (SLD)
0
1 (LD)
NOTE
• Reducing the PWM carrier frequency is effective as a countermeasure against EMI from the inverter or for reducing leakage
current, but doing so increases the motor noise.
• When the PWM carrier frequency is set to 1 kHz or lower (Pr.72 ≤ 1), the increase in the harmonic current causes the fast-
response current limit to activate before the stall prevention operation, which may result in torque shortage. In this case,
disable the fast-response current limit in Pr.156 Stall prevention operation selection.
Parameters referred to
Pr.156 Stall prevention operation
Pr.570 Multiple rating
settingpage 194
Pr.800 Control method
selectionpage 169
5.4.19 Inverter parts life display
The degree of deterioration of the control circuit capacitor, main circuit capacitor, cooling fan, and inrush current limit circuit can
be diagnosed on the monitor.
When a part approaches the end of its life, an alarm can be output by self diagnosis to prevent a fault.
(Note that the life diagnosis of this function should be used as a guideline only, because with the exception of the main circuit
capacitor, the life values are theoretical calculations.)
Pr.
255
Life alarm status display
E700
256
Inrush current limit circuit life
*2
display
E701
257
Control circuit capacitor life
E702
display
258
Main circuit capacitor life display 100%
*2
E703
259
Main circuit capacitor life
*2
measuring
E704
*1
Valid values (read only) for separated converter type inverters are "0, 1, 4, and 5". The setting range (reading only) for IP55 compatible modes
is "0 to 31".
*2
The setting is available only for standard models and IP55 compatible models.
208
5. PARAMETERS
5.4 (E) Environment setting parameters
The carrier frequency will reduce automatically with continuous operation of 85% of the inverter rated
current or higher.
The carrier frequency will reduce automatically with continuous operation of 85% of the inverter rated
current or higher.
Without carrier frequency automatic reduction (Perform continuous operation with the carrier frequency
set to 2 kHz or lower or with less than 85% of the inverter rated current for the ND rating.)
selectionpage 273
Name
Initial value
0
100%
100%
0
Carrier frequency automatic reduction operation
Setting range
Displays whether or not the parts of the control circuit
capacitor, main circuit capacitor, cooling fan, and
*1
(0 to 15)
inrush current limit circuit have reached the life alarm
output level. Read-only.
Displays the deterioration degree of the inrush current
(0 to 100%)
limit circuit. Read-only.
Displays the deterioration degree of the control circuit
(0 to 100%)
capacitor. Read-only.
Displays the deterioration degree of the main circuit
capacitor. Read-only.
(0 to 100%)
The value measured by Pr.259 is displayed.
Setting "1" and turning the power supply OFF starts the
measurement of the main circuit capacitor life.
If the setting value of Pr.259 becomes "3" after turning
0, 1 (2, 3, 8, 9)
the power supply ON again, it means that the
measurement is completed. The deterioration degree is
read to Pr.258.
Description