Mitsubishi Electric 800 Series Instruction Manual page 228

 Displayed unit switchover (Pr.37, Pr.53, and Pr.505)
• The rotation speed or machine speed can be displayed for monitoring or used for parameter setting instead of the
frequency by using Pr.53.
• To display the machine speed, set Pr.37 to the value which corresponds to the speed of machine operated at the frequency
set in Pr.505.
For example, when Pr.505 is set to 60 Hz and Pr.37 is set to "1000", the operation panel indicates "1000" as the monitor
value of machine speed while the output frequency is 60 Hz. "500" is displayed while the output frequency is 30 Hz.
• The operation panel indicates the upper 4 digits when the rotation speed or machine speed is displayed. For example,
when the internal value "1770.950" is monitored, the operation panel indicates "1770".
Output frequency
Pr.53 setting
indication
0 (initial value) 0.01 Hz
*1
1
1 r/min
0.001 (machine
4
*1
speed )
*1 Motor speed r/min conversion formula: frequency × 120 / number of motor poles (Pr.81 or Pr.454)
Machine speed conversion formula: Pr.37 × frequency / Pr.505
The item set in Pr.505 is consistently a frequency (Hz).
When Pr.81 (Pr.454) = "9999", the number of motor poles is regarded as 4.
NOTE
• The inverter's output frequency is displayed as synchronous speed under V/F control. The displayed value is "actual motor
speed" + "motor slip". When Advanced magnetic flux vector control, Real sensorless vector control, or PM sensorless vector
control is selected, the actual motor speed (estimated value by motor slip calculation) is used.
• To change the main monitor of the operation panel (operation panel main display), refer to Pr.52.
• Since the panel display of the operation panel is in 4 digits, the monitor value of more than "9999" is displayed as "----". Display
the frequency on the operation panel when a value equal to or more than 10000 r/min needs to be monitored or set.
• The displayed machine speed is the value converted from the frequency. Therefore, the setting value and read value may
fluctuate due to rounding during the conversion.
CAUTION
• Make sure to set the running speed and the number of motor poles.
Otherwise, the motor might run at extremely high speed, damaging the machine.
Parameters referred to
Pr.1 Maximum frequencypage 211
Pr.52 Operation panel main monitor
Pr.81 Number of motor polespage 86
Pr.800 Control method selectionpage 86
Set frequency
indication
0.01 Hz
*1
1 r/min
0.001 (machine
*1
speed )
selectionpage 228
Running speed
Frequency setting
indication
*1
0.01 Hz
1 r/min
*1
1 r/min 1 r/min
0.001 (machine
*1
1 (machine speed )
*1
speed
11. (M) Item and Output Signal for Monitoring
11.1 Speed indication and its setting change to rotations per minute
Parameter setting
0.01 Hz
*1 *1
1 r/min
0.01 Hz
)
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