Yaskawa Z1000 AC Drive HVAC User Manual
Page 178
Setting 1: Protection Enabled at Low Speed
The overload protection level (oL2 fault detection level) is automatically reduced at speeds below 6 Hz. At zero speed, the
overload is derated by 50%.
n
L8-18: Software Current Limit Selection
Enables and disables the Software Current Limit (CLA) protection function to prevent main circuit transistor failures caused
by high current.
Note:
Do not change this setting unless absolutely necessary.
No.
Name
Setting Range
Default
L8-18
Software Current Limit Selection
0, 1
0
Setting 0: Software CLA Disabled
The drive may trip on an oC fault if the load is too heavy or the acceleration is too short.
Setting 1: Software CLA Enabled
When the Software CLA current level is reached, the drive reduces the output voltage to reduce the current. Normal operation
continues when the current level drops below the Software CLA level.
n
L8-19: Frequency Reduction Rate during Overheat Pre-Alarm
Specifies the output frequency reduction when L8-03 is set to 4 and an oH alarm is present. Set as a factor of the maximum
output frequency.
No.
Name
Setting Range
Default
L8-19
Frequency Reduction Rate During Overheat Pre-Alarm
0.0 to 100.0%
20.0%
n
L8-27: Overcurrent Detection Gain
Adjusts the overcurrent detection level in OLV/PM control mode. A setting of 100% is equal to the motor rated current. When
the drive rated current is considerably higher than the motor rated current, use this parameter to decrease the overcurrent level
and prevent motor demagnetization from high current.
Overcurrent detection uses the lower value between the overcurrent level for the drive and the motor rated current multiplied
by L8-27.
No.
Name
Setting Range
Default
L8-27
Overcurrent Detection Gain
0.0 to 400.0%
300.0%
n
L8-29: Current Unbalance Detection (LF2)
Enables or disables output current unbalance detection in OLV/PM control mode. Current unbalance can heat a PM motor
and demagnetize the magnets. The current unbalance detection function monitors output current and triggers the LF2 fault to
prevent such motor damage.
No.
Name
Setting Range
Default
L8-29
Current Unbalance Detection (LF2)
0, 1
1
Setting 0: Disabled
No current unbalance protection is provided to the motor.
Setting 1: Enabled
The LF2 fault is triggered if an output current unbalance is detected. Drive output shuts off and the motor coasts to stop.
n
L8-32: Main Contactor and Cooling Fan Power Supply Failure Selection
Determines drive operation when a FAn fault occurs.
No.
Name
Setting Range
Default
L8-32
Main Contactor and Cooling Fan Power Supply Failure Selection
0 to 4
1
Setting 0: Ramp to Stop
The drive stops the motor using the deceleration time set in parameter C1-02.
4.13 Advanced Drive Setup Adjustments
178
YASKAWA ELECTRIC TOEP YAIZ1U 03A YASKAWA AC Drive – Z1000 User Manual