# Mitsubishi Electric FR-F820-00046 Instruction Manual Page 288

Fr-f800 series.

*1
The maximum value of the setting range differs according to the Pr.1 Maximum frequency, Pr.505 Speed setting reference, and it can be
calculated from the following formula.
The maximum value of Pr.37 < 65535 × Pr.505 / Pr.1 setting value (Hz).
The maximum setting value of Pr.37 is 9998 if the result of the above formula exceeds 9998.
 Indication of motor speed (Pr.37, Pr.144)
• To change the indication to the motor speed, set the number of motor poles (2, 4, 6, 8, 10, or 12) or the number of motor
poles with the addition of 100 (102, 104, 106, 108, 110, or 112) in Pr.144.
• Whenever the number of motor poles set in Pr.81 Number of motor poles is changed, the Pr.144 setting changes
automatically in conjunction with Pr.81. However, the Pr.81 setting does not automatically change when the Pr.144 setting
is changed.
Example 1) Changing the initial value of Pr.81 to "2" will change the Pr.144 setting from "4" to "2".
Example 2) Changing the Pr.81 setting to "2" while Pr.144 = "104" will change the Pr.144 setting from "104" to "102".
 Indication of machine speed (Pr.37, Pr.505)
• To change the indication to the machine speed, set a number in Pr.37 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 machine is operated at the frequency of 60 Hz. "500" is displayed while the running
frequency is 30 Hz.
 Monitoring/setting items and its increments
• When both settings of Pr.37 and Pr.144 are changed from the initial values, a precedence order for these settings is as
follows:
Pr.144 = 102 to 112 > Pr.37 = 1 to 9998 > Pr.144 = 2 to 12.
• The monitoring/setting items and its increments are listed with the following matrix to show the combination of the Pr.37
and Pr.144 settings.
Pr.37 setting Pr.144 setting
0
0 (initial
2 to 12
value)
102 to 112
0
1 to 9998
2 to 12
102 to 112
*1
Motor speed r/min conversion formula: frequency × 120 / number of motor poles (Pr.144)
Machine speed conversion formula: Pr.37 × frequency / Pr.505
The Pr.144 value in the above formula is "Pr.144 - 100" when any of "102 to 112" is set in Pr.144. The value is "4" when Pr.37 = 0 and Pr.144 = 0.
The item set in Pr.505 is consistently a frequency (Hz).
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 or PM motor control is selected, the actual motor speed
(estimated value by motor slip calculation) is used.
• When Pr.37 = "0" and Pr.144 = "0", the running speed monitor is displayed with the number of motor poles 4. (Displays 1800
r/min at 60 Hz)
• To change the PU main monitor (PU main display), refer to Pr.52.
• When using the machine speed display for the parameter unit (FR-PU07), do not change the speed with the up/down key if a
set speed above 65535 is displayed. The set speed may become an undetermined value.
• When the FR-A8ND is connected, the frequency display (setting) is used regardless of the Pr.37, Pr.144 settings.
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.
Output frequency
Set frequency indication
indication
0.01 Hz
0.01 Hz
0.01 Hz (initial setting) 0.01 Hz (initial setting)
*1
*1
1 r/min
1 r/min
0.01 Hz
0.01 Hz
*1
1 (machine speed
)
1 (machine speed
0.01 Hz
0.01 Hz
Running speed
indication
*1
1 r/min
*1
(initial setting) 0.01 Hz (initial setting)
1 r/min
*1
1 r/min
*1
1 (machine speed
)
*1
*1
)
1 (machine speed
)
*1
1 r/min
5.8 (M) Item and output signal for monitoring
Indication of frequency
setting parameter
0.01 Hz
*1
1 r/min
0.01 Hz
*1
1 (machine speed
)
0.01 Hz
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5. PARAMETERS
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