Yaskawa F7 Drive Programming Manual - Manual (Page 142)

Programming 134
L8-15 OL2 Characteristic Selection at Low Speeds
At very low speeds (6 Hz and below) and very high current levels it can be possible to damage output transistors. Therefore the
factory default setting of L8-15 is to shorten the time before an OL2 fault will occur during low speed/high load situations (L8-
15= “1: Enabled”).
L8-18 Soft CLA Selection
The Soft CLA (software current limit level) is a Drive protection function that will limit the Drive’s output current. The Drive
limits the output current by reducing the output frequency whenever the current exceeds 110% of the inverter rated current. If
the current level drops below the Soft CLA level, then normal operation will continue.
If the software current limit is disabled (L8-18= “0: Disabled”), the Drive may trip on an OC fault if the load is prohibitively
large or the acceleration is too short. For proper Drive protection and operation leave the Soft CLA function enabled.
n1 Hunting Prevention
n1-01 Hunting Prevention Selection
n1-02 Hunting Prevention Gain Setting
Setting Range: 0.00 to 2.50
Factory Default: 1.00
Sometimes when the Drive is lightly loaded and the carrier frequency is high, the Drive’s output current may vary, or hunt.
This varying current can cause the motor to vibrate. The Drive’s Hunting Prevention function can stabilize the motor’s
magnetizing current by adjusting the output voltage (n1-01= “1: Enabled”). The Hunting Prevention function can eliminate the
vibration but at the cost of Drive response.
Parameter n1-02 can adjust the gain of the Hunting Prevention function if it is enabled by n1-01. Normally there is no need to
adjust n1-02 from the factory default setting. Make adjustments in the following cases:
• If vibration occurs with a light load, increase the setting of n1-02.
• If the motor stalls, reduce the setting of n1-02.
An overly large Hunting Prevention Gain (n1-02) may cause the motor to stall.
Setting Description
0 Disabled
1 Enabled (L8-18 is active) (factory default)
Setting Description
0 Disabled
1 Enabled (factory default)
Setting Description
0 Disabled
1 Enabled (factory default)