Setting 2: Fast Stop
If an overheat alarm occurs, the drive decelerates to stop using the Fast Stop time (C1-09). If a digital output is programmed
for “fault” (H2-
oo
= E), this output will be triggered.
Setting 3: Alarm Only
If an overheat alarm occurs, an alarm is output and the drive continues operation.
Setting 4: Operation with Reduced Speed
If an overheat alarm occurs, the operation continues with the speed reduced to the level set to parameter L8-19. If the oH alarm
is still present after 10 s, the speed is reduced again. The amount of speed reduction depends on how often the alarm repeats.
If the oH alarm disappears while the drive is operating at a reduced speed, the drive will switch to the previous speed in 10 s
increments until reaching base frequency.
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.
10 s
etc.
time
10 s
10 s
10 s
10 s
10 s
10 s
f
ref
× (L8-19)
f
ref
× (L8-19)
2
f
ref
× (L8-19)
4
f
ref
× (L8-19)
3
f
ref
Output frequency
Reset oH
Alarm
Reset oH
Alarm
Digital output (4D)
oH
Alarm
oH
Alarm
oH
Alarm
oH
Alarm
oH alarm number
Figure 1.75 Output Frequency Reduction During Overheat Alarm
n
L8-06: Input Phase Loss Detection Level
Sets the Input Phase Loss Detection (PF) Level.
Triggers PF fault when there is an imbalance larger than the value set to L8-06 in the drive input power voltage.
Detection Level = 100% = Voltage Class ×
No.
Name
Setting Range
Default
L8-06
Input Phase Loss Detection Level
0.0 to 50.0%
Determined by
o2-04
n
L8-07: Output Phase Loss Protection Selection
Enables or disables the output phase loss detection.
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
L8-07
Output Phase Loss Protection Selection
0 to 2
1
Setting 0: Disabled
Setting 1: Fault when One Phase Is Lost
An output phase loss fault (LF) is triggered when the output current for any phase U, V, or W drops to 5% or less of the drive
rated current.
1.8 L: Protection Functions
124
YASKAWA ELECTRIC SIEP C710636 10C Z1000U HVAC MATRIX Drive Programming Manual
