Yaskawa AC Drive Z1000 AC Drive HVAC Fan - Manual (Page 120)

n L8-15: oL2 Characteristics Selection at Low Speeds
Selects whether the drive overload capability (oL fault detection level) is reduced at low speeds to prevent premature output
transistor failures.
Note: Contact Yaskawa for consultation before disabling this function. Disabling this function may shorten the operating life of the power
transistors.
No. Name Setting Range Default
L8-15 oL2 Characteristics Selection at Low Speed 0, 1 1
Setting 0: Protection Disabled at Low Speed
The overload protection level is not reduced. Frequently operating the drive with high output current at low speed can lead to
premature drive faults.
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 L8-27: 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.
1.8 L: Protection Functions
120 YASKAWA ELECTRIC SIEP YAIZ1U 03A YASKAWA AC Drive – Z1000 Programming Manual