Mitsubishi Electronics FR-A740-0.4k to 500k ユーザーズマニュアル
19/24
BCN-C22005-634
3
Speed detection hysteresis (Pr.870)
4
Limit regeneration avoidance operation frequency (Pr. 885)
Operation Panel
Indication
E.OV3
FR-PU04
FR-PU07
FR-PU07
OV During Dec
Name
Regenerative overvoltage trip during deceleration or stop
Description
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the
specified value, the protective circuit is activated to stop the inverter output. The circuit may also be
activated by a surge voltage produced in the power supply system.
specified value, the protective circuit is activated to stop the inverter output. The circuit may also be
activated by a surge voltage produced in the power supply system.
Check point
· Check for sudden speed reduction.
Check if the stall prevention operation is frequently activated in an application with a large
load inertia.
load inertia.
Corrective action
· Increase the deceleration time. (Set the deceleration time which matches the moment of inertia of the
load)
· Set the brake cycle longer.
· Use the regeneration avoidance function (Pr. 882 to Pr. 886). (
· Use the regeneration avoidance function (Pr. 882 to Pr. 886). (
Refer to Chapter 4 of the Instruction
Manual (Applied).)
· Use the brake unit or power regeneration common converter (FR-CV) as required.
Set Pr.154 Voltage reduction selection during stall prevention operation = "10 or 11". (
Refer to
Chapter 4 of the Instruction Manual (Applied).)
This function prevents chattering of the speed detection signals.
Parameter
Number
Name
Initial
Value
Value
Setting
Range
Description
870
Speed detection
hysteresis
0Hz*
0 to 5Hz
Set the hysteresis width for the detected frequency.
* Performing IPM parameter initialization changes the settings. (Refer to page 6)
When an output frequency fluctuates, the following
signals may repeat ON/OFF (chatters).
signals may repeat ON/OFF (chatters).
Up to frequency (SU)
Speed detection (FB, FB2, FB3)
Low speed output (LS)
Setting hysteresis to the detected frequency prevents
chattering of these signals.
chattering of these signals.
REMARKS
Setting a higher value to this parameter slows the response of frequency detection signals (SU, FB, FB2, FB3, and LS).
The ON/OFF logic for the LS signal is opposite for the FB signal.
The setting range of Pr.885 Regeneration avoidance compensation frequency limit value has been changed.
Parameter
Number
Name
Initial
Value
Value
Setting
Range
Description
885
Regeneration
avoidance
compensation
frequency limit value
avoidance
compensation
frequency limit value
6Hz
0 to 30Hz
Set the limit value of frequency which rises at
activation of regeneration avoidance function.
activation of regeneration avoidance function.
9999
Frequency limit invalid
Pr.870
Pr.42
Output
frequency
(Hz)
frequency
(Hz)
ON
ON
ON
FB
Example of the speed detection (FB) signal
OFF
OFF
bcnc22005634.fm 19 ページ ２０１２年７月３日 火曜日 午前９時４３分