Mitsubishi Electric FR-A820-00046 Instruction Manual page 328

Speed control under Real sensorless vector control, vector control, PM sensorless vector control
NOTES The deceleration check is enabled in the speed control of the vector control.
If the protective function (E.OSD) operates due to deceleration check, check whether the Pr. 369
(Pr. 851) "Number of encoder pulses" setting is correct.
Parameters referred to
Pr. 285
Pr. 369
Pr. 851
5 - 126
Overspeed detection frequency
Number of encoder pulses
Control terminal option-Number of encoder pulses
Parameters
=> page 5-730
=> page 2-83
=> page 2-83