Avoiding Motor Overrunning - Mitsubishi Electric 800 Series Instruction Manual

5.5

Avoiding motor overrunning

PM PM PM
Motor overrunning due to excessive load torque can be avoided.
Pr. Name
285 Speed deviation excess detection
H416 frequency
853
Speed deviation time
H417
 Speed deviation excess detection (Pr.285, Pr.853)
• A shutoff can be set for when the deviation between the set frequency and the rotation speed (estimated value) is large,
such as when the load torque is excessive.
• When the difference (absolute value) between the speed command value and the rotation speed (estimated value) is equal
to or higher than the setting value in Pr.285 Speed deviation excess detection frequency for a continuous time equal
to or longer than the setting value in Pr.853 Speed deviation time, the speed deviation excess detection (E.OSD) is
activated to shut off the inverter output.
Fault output
(ALM)
excessive fault activated
NOTE
• This function is enable at a frequency equal to or higher than 10% of the rated motor frequency.
Initial value
9999
1.0 s
Set frequency
Pr.285
Rotation speed (estimated value)
Time
Pr.853
OFF ON
Speed deviation
(E. OSD)
Setting
range
Set the speed deviation excess detection frequency
(difference between the rotation speed (estimated value)
0 to 30 Hz
and the speed command value) at which the protective
function (E.OSD) activates.
9999 No speed deviation excess
Set the time from when the speed deviation excess state
0 to 100 s is entered to when the protective function (E.OSD)
activates.
Description
5. Speed control
5.5 Avoiding motor overrunning
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