YASKAWA GA700 Series Technical Manual page 902

12.9 L: Protection Functions
Note:
The drive applies a hysteresis of approximately 10% of the drive rated output current or the motor rated torque to the overtorque/
undertorque detection function.
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Mechanical Weakening Detection
The Mechanical Weakening Detection function detects the mechanical weakening of a machine that can cause
overtorque or undertorque because of motor speed and total drive operation time.
The drive activates the function if the drive total operation time is longer than the time set in L6-11 [Mech Fatigue
Hold Off Time]. You can use U4-01 [Cumulative Ope Time] to monitor the total operation time.
Parameter Settings
The drive detects Mechanical Weakening if overtorque or undertorque occur during the speed range set in L6-08
[Mechanical Fatigue Detect Select] and L6-09 [Mech Fatigue Detect Speed Level] for the length of time set in
L6-10 [Mech Fatigue Detect Delay Time]. The drive uses L6-01 to L6-03 [Torque Detection 1 Setting Parameter]
to detect oL5 [Mechanical Weakening Detection 1] or UL5 [Mechanical Weakening Detection 2]. Parameter L6-
08 sets the operation after detection.
Set the terminal that outputs the fault in H2-01 to H2-03 [MFDO Function Select].
MFDO Function Select
• Terminals M1-M2
• Terminals M3-M4
• Terminals M5-M6
Operation Selection after Detection
Detection Start Time
Speed Range
Overtorque
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L6-01: Torque Detection Selection 1
No.
Name
(Hex.)
L6-01 Torque Detection Selection
1
(04A1)
The drive detects overtorque if the motor current or output torque is more than the level set in L6-02 [Torque
Detection Level 1] for the length of time set in L6-03 [Torque Detection Time 1]. The drive detects undertorque if
the motor current or output torque is less than the level set in L6-02 for the length the time set in L6-03.
0 : Disabled
The drive will not detect overtorque or undertorque.
1 : oL @ Speed Agree - Alarm only
902
Figure 12.143 Undertorque Detection Time Chart
Table 12.76 Mechanical Weakening Detection Settings Parameters
Configuration Parameter
Detection Criteria
Detection Level
Detection Time
Detection Criteria
Detection Level
Detection Time
V/f CL-V/f OLV
Sets torque detection conditions that will trigger an overtorque or undertorque response from the
drive.
Description
CLV AOLV OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
YASKAWA SIEPC71061705H GA700 Series Technical Manual
Mechanical Deterioration Detection
H2-01, H2-02, and H2-03 = 22
L6-08
L6-11
L6-08
L6-09
L6-10
L6-01
L6-02
L6-03
Default
(Range)
0
(0 - 8)