Mitsubishi FR-A800

(H) Protective function parameter
PARAMETERS
355
5
GROUP
H
5.10.12 Motor overspeeding detection
 The motor maximum frequency is set in Pr.702 Maximum motor frequency. When Pr.702 = "9999 (initial value)", the Pr.84 Rated motor
frequency setting is applied as the motor maximum frequency.
NOTE
• During encoder feedback control and vector control, the motor speed is compared against Pr.374. During Real sensorless
vector control and PM sensorless vector control, the output frequency is compared against Pr.374.
The Overspeed occurrence (E.OS) is activated when the motor speed exceeds the overspeed detection level. This
function prevents the motor from accidentally speeding over the specified value, due to an error in parameter setting,
etc.
Pr. Name
Initial
value
Setting
range
Description
374
H800
Overspeed detection
level
9999
0 to 590 Hz
If the motor rotation speed exceeds the speed set in Pr.374
during encoder feedback control, Real sensorless vector
control, vector control or PM sensorless vector control,
Overspeed occurrence (E.OS) occurs, the inverter output is
shut off.
9999
If the speed exceeds "the maximum speed (Pr.1, Pr.18) + 20
Hz" during encoder feedback control, Real sensorless vector
control, or vector control, E.OS occurs.
During PM sensorless vector control, E.OS occurs when the
speed exceeds "the motor maximum frequency + 10 Hz"

ALM
Motor speed
Time
E.OS
Coast to stop
ON
Pr.374