Mitsubishi Electric FR-A760 Series Instruction Manual page 249

Monitor display and monitor output signal
⋅ To display the machine speed, set in Pr. 37 the machine speed for operation with frequency set in Pr. 505.
For example, when Pr. 505 = "60Hz" and Pr. 37 = "1000", "1000" is displayed on the running speed monitor when the
running frequency is 60Hz. When running frequency is 30Hz, "500" is displayed.
⋅ When displaying the motor speed, set the number of motor poles (2, 4, 6, 8, 10) or number of motor poles + 100
(102, 104, 106, 108, 110) in Pr. 144.
⋅ The Pr. 144 setting is automatically changed if the number of motor poles is set in Pr.81 Number of motor poles. The Pr.
81 setting is not automatically changed even if the setting of Pr. 144 is changed.
Example 1) When the initial setting of Pr. 81 is changed to "2" or "12", the Pr. 144 setting changes from "4" to "2".
Example 2) When Pr. 144 = "104", setting "2" in Pr. 81 changes the Pr. 144 setting from "104" to "102".
⋅ When "1, or 11" is set in Pr. 811, the setting increments of speed setting from the PU, speed setting from RS-485
communication or communication options (other than FR-A7ND, FR-A7NL) and running speed monitor is 0.1r/min.
⋅ When both Pr. 37 and Pr. 144 have been set, their priorities are as given below.
Pr. 144, 102 to 110 > Pr. 37, 1 to 9998 > Pr. 144, 2 to 10
⋅ When the running speed monitor is selected, each monitor and setting are determined by the combination of Pr. 37
and Pr. 144 as listed below. (The units within the thick frame are the initial values.)
Pr. 37 Pr. 144
Setting Setting
0
0
(initial 2 to 10
value)
102 to 110
0
1 to 9998 2 to 10
102 to 110
Motor speed r/min conversion formula............ frequency × 120/number of motor poles (Pr. 144)
*1
Machine speed conversion formula ...................Pr. 37 × frequency/Pr. 505
For Pr. 144 in the above formula, the value is "Pr. 144 - 100" when "102 to 110" is set in Pr. 144 and the value is "4" when Pr. 37 = 0 and Pr. 144 = 0.
*2 Hz is in 0.01Hz increments, machine speed is in 1 increments, and r/min is in 1r/min increments (depending on Pr. 811).
*3 Pr. 505 is always set as frequency (Hz).
CAUTION
⋅ In the V/F control mode, the output frequency of the inverter is displayed in terms of synchronous speed, and therefore, it is
unequal to the actual speed by motor slip. This display changes to the actual speed (estimated value calculated based on the
motor slip) when the advanced magnetic flux vector control or real sensorless vector control is selected, and actual speed from
the encoder when encoder feed back control or vector control is performed.
⋅ When the running speed display is selected at the setting of Pr. 37 = "0" and Pr. 144 = "0", the monitor display is provided on the
assumption that the number of motor poles is 4. (1800r/min is displayed at 60Hz)
⋅ Refer to Pr. 52 when you want to change the PU main monitor (PU main display).
⋅ Since the panel display of the operation panel (FR-DU07) is 4 digits in length, the monitor value of more than "9999" is
displayed "----".
⋅ After setting the running speed in 0.1r/min increments (Pr. 811 = "1, 11"), changing the setting increments to 1r/min increments
(Pr. 811 = "0, 10") changes the speed resolution from 0.1r/min to 0.3r/min (four poles), which may round down 0.1r/min
increments.
⋅ When the machine speed is displayed on the FR-PU04/FR-PU07, do not change the speed by using an up/down key in the
state where the set speed exceeding 65535 is displayed. The set speed may become arbitrary value.
⋅ When an optional FR-A7ND or FR-A7NL card is mounted, frequency is displayed regardless of Pr. 37 and Pr. 144 setting.
Make sure that the settings of the running speed and number of motor poles are correct. Otherwise, the motor
might run at extremely high speed, damaging the machine.
♦ Parameters referred to ♦
Pr. 1 Maximum frequency
Pr. 52 DU/PU main display data selection
Pr. 80 Motor capacity, Pr. 81 Number of motor poles
Pr. 800 Control system selection
Pr. 811 Set resolution switchover
238
Output Frequency
Monitor
Hz
Hz
r/min
*1
Hz
Machine speed
*1
Hz
Refer to page 145
Refer to page 239
Refer to page 134
Refer to page 78
Refer to page 86
Set Frequency Running Speed
Monitor
Hz
Hz
r/min
*1
Hz Machine speed
Machine speed Machine speed
*1
Hz
CAUTION
Frequency Setting
Monitor Parameter Setting
r/min
*1
r/min
*1
r/min r/min
*1
*1
Machine speed
*1
r/min
*1
Hz
Hz
*1
Hz
*1
Hz