Mitsubishi Electric FR-A700 Series, Техническое руководство, Страница: 260 / 550

294
PARAMETER
(5) Torque bias operation [ Pr. 844, Pr. 845 ]
When [ Pr. 844 Torque bias filter
≠
9999], you can slow
the rise of torque. At this time, the torque rises
according to the time constant of the primary delay
filter.
Set the time for output torque be maintained with the
torque bias command value alone in [
Pr. 845 Torque
bias operation time ] .
2.9.6 Speed limit [Pr. 285, 853, 873]
(A700)
This function prevents the motor from overrunning when the load torque is too large and incorrect number of encoder is set.
(1) Speed deviation excessive [ Pr. 285, 853 ]
When the deviation between the set frequency and
actual speed is large, e.g. too large load torque, this
function can cause the inverter to provide a speed
deviation excessive fault (E.OSD) and come to trip.
(2) Speed limit [ Pr. 873 ]
This function prevents the motor from overrunning
when the setting of number of encoder pulses and
the actual number differ.
When the setting of number of encoder pulses is
smaller than the actual number, the motor may
increase its speed. To prevent this, restrict the output
speed by the frequency(set frequency and [
Pr. 873 ]).
Speed
Torque bias
Torque bias filter
primary delay time
constant
Time when torque is
generated by
torque bias setting
Pre-excitation LX
*
Start signal
[ Pr. 844 ]
[ Pr. 845 ]
Output torque
* When not performing pre-excitation, the torque bias functions simultaneously with the start signal.
[
Pr.
] Name Initial Value Setting Range Description
285
Speed deviation excess
detection frequency
*1
9999
9999 Without speed deviation excessive
0 to 30Hz
If the difference (absolute value) between the speed
command value and actual speed exceeds the [
Pr. 285
Speed deviation excess detection frequency
] setting for
longer than the time set in [
Pr. 853 Speed deviation time
],
speed deviation excessive occurs and error "E. OSD"
appears, resulting in a stop.
853
Speed deviation time
1.0s 0 to 100s
873
Speed limit
20Hz 0 to 120Hz Frequency is limited at the set fre [ Pr. 873 ].
*1 Acts as over speed detection frequency under encoder feedback operation. (Refer to page 392)
A700
Set frequency
Actual speed
Time
Speed deviation
excessive fault activated
(E. OSD)
ON OFF
Fault output
(across A-C)
[ Pr. 853 ]
[ Pr. 285 ]
Frequency
(Hz)
Actual speed
at error occurrence
Set speed + [ Pr. 873 ] value
Value of [ Pr. 873 ]
Set speed
Speed during
normal operation.