EQ7 Series Instruction Manual - TECO-Westinghouse Motor Company

F26, F27 Motor Sound (Carrier frequency and Tone) H98 (Protection/Maintenance Function (Mode selection))
• 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.
Item Characteristics Remarks
0.75 to 16 kHz
0.5 to 30 HP (VT mode)
0.5 to 75 HP (CT, CT-V mode)
Carrier frequency
0.75 to 10 kHz
40 to 100 HP (VT mode)
125 to 800 HP (CT-V mode)
0.75 to 6 kHz
125 to 900 HP (VT mode)
800 and 900 HP (CT-V mode)
0.75 to 4 kHz 1000 HP (VT mode)
0.75 to 2 kHz 150 to 700HP (CT Mode)
Motor sound noise emission High Low
Motor temperature
(due to harmonics components)
High Low
Ripples in output current
waveform
Large Small
Leakage current Low High
Electromagnetic noise emission Low High
Inverter loss Low High
VT = Variable Torque, CT = Constant Torque, CT-V = Constant Torque Vector
Specifying a too low carrier frequency will cause the output current waveform to have a large amount of
ripples. As a result, the motor loss increases, causing the motor temperature to rise. Furthermore, the
large amount of ripples tends to cause a current limiting alarm. When the carrier frequency is set to 1 kHz
or below, therefore, reduce the load so that the inverter output current comes to be 80% or less of the
rated current.
When a high carrier frequency is specified, the temperature of the inverter may rise due to a surrounding
temperature rise or an increase of the load. If it happens, the inverter automatically decreases the carrier
frequency to prevent the inverter overload alarm 0lu . With consideration for motor noise, the automatic
reduction of carrier frequency can be disabled. Refer to the description of H98.
It is recommended to set the carrier frequency at 5 kHz or above under vector control without/with speed
sensor. DO NOT set it at 1 kHz or below.
• Motor Sound (Tone) (F27)
F27 changes the motor running sound tone (only for motors under V/f control). 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.
Data for F27
Function
0 Disable (Tone level 0)
1 Enable (Tone level 1)
2 Enable (Tone level 2)
3 Enable (Tone level 3)
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