5.8 L: Protection Functions
270 YASKAWA ELECTRIC SIEP C710616 27C YASKAWA AC Drive A1000 Technical Manual
Setting 4: Operation with reduced speed
If an overheat alarm occurs, the operation is continued but the speed is reduced to the level set in parameter L8-19. If
after 10 s the oH alarm is still present, the speed is reduced once more. The amount of reduction depends on how often
the alarm repeats. If the oH alarm disappears while the drive is operating at a reduced speed, then the drive will switch
back to the previous speed it was reduced to before. Figure 5.104 explains the operation with reduced speed during an
oH alarm. A digital output programmed for 4D is switched when the oH alarm is still active after ten reduction cycles.
Figure 5.10 4
Figure 5.104 Output Frequency Reduction During Overheat Alarm
■ L8-19: Frequency Reduction Rate during Overheat Pre-Alarm
Specifies how much the output frequency is reduced when L8-03 is set to 4 and an oH alarm is present. Set as a factor of
the maximum output frequency.
■
L8-05: Input Phase Loss Protection Selection
Enables or disables the input phase loss detection.
Setting 0: Disabled
Setting 1: Enabled
Enables input phase loss detection. As detection is performed by measuring the DC bus ripple, a phase loss fault (PF) can
also be triggered by a power supply voltage imbalance or main circuit capacitor deterioration. Detection is disabled if:
• The drive is decelerating.
• No Run command is active.
• Output current is less than or equal to 30% of the drive rated current.
■
L8-07: Output Phase Loss Protection Selection
Enables or disables the output phase loss detection, which is triggered when the output current falls below 5% of the
drive rated current.
Note: 1. Output phase loss detection can mistakenly be triggered if the motor rated current is very small compared to the drive rating. Disable
this parameter in such cases.
2. Output phase loss detection is not possible when the drive is running a PM motor with light load.
No. Name Setting Range Default
L8-19 Frequency Reduction Rate During Overheat Pre-Alarm 0.1 to 0.9 0.8
No. Name Setting Range Default
L8-05 Input Phase Loss Protection Selection 0 or 1 1
To Next Page
Loading...
Need help?
General
