Fuji Electric FRENIC-HVAC User Manual page 380

F26, F27 Motor Sound (Carrier frequency and Tone)
Motor Sound (Carrier frequency) (F26)

F26 controls the carrier frequency so as to reduce an audible noise generated by the motor or
electromagnetic noise from the inverter itself, and to decrease a leakage current from the
main output (secondary) wirings.
Carrier frequency
Motor sound noise emission
Motor temperature
(due to harmonics components)
Ripples in output current waveform
Leakage current
Electromagnetic noise emission
Inverter loss
Basically, do not change the carrier frequency from the default value (2 kHz).
Increasing it requires derating of the output current. For details, refer to Chapter 2,
Section 2.6 "Derating of Rated Output Current."
When a high carrier frequency is specified, the temperature of the inverter may rise
due to an ambient temperature rise or an increase of the load. If it happens, the
inverter automatically decreases the carrier frequency to prevent the inverter
overload alarm OLV. With consideration for motor noise, the automatic reduction
of carrier frequency can be disabled. Refer to the description of H98.
Motor Sound (Tone) (F27)

F27 changes the motor running sound
tone. This setting is effective when the
carrier frequency specified by function
code F26 is 7 kHz or lower. Changing the
tone level may reduce the high and harsh
running noise from the motor.
If the tone level is set too high, the output current may become unstable, or
mechanical vibration and noise may increase. Also, this function code may not be
very effective for certain types of motor.
H98 (Protection/Maintenance Function, Mode selection)
Item
6-70
Characteristics
230 V class series:1 to 25 HP
0.75 to 16 kHz
460 V class series:1 to 50 HP
575 V class series:1 to 50 HP
230 V class series:30 to 100 HP
0.75 to 10 kHz
460 V class series:60 to 125 HP
575 V class series:60 to 125 HP
230 V class series: 125 HP
0.75 to 6 kHz
460 V class series:150 to 900 HP
575 V class series:150 to 300 HP
0.75 to 4 kHz 460 V class series: 1000 HP
High ↔ Low
High ↔ Low
Large ↔ Small
Low High
↔
Low ↔ High
Low ↔ High
Data for F27
0 Disable (Tone level 0)
1 Enable (Tone level 1)
2 Enable (Tone level 2)
3 Enable (Tone level 3)
Remarks
Function