YASKAWA Varispeed L7, Инструкция по эксплуатации, Страница: 170 / 243

Inverter Protection
5-
41
5
‹
Output Open Phase Protection
This function detects an open output phase by comparing the output current value of each phase with an inter-
nal set output open phase detection level (5% of inverter rated current). The detection will not work when the
output frequency is below 2% of the base frequency.
Three settings are available:
•
L8-07=0, no output open phase detection
•
L8-07=1, the loss of one phase is detected only
•
L8-07=2, the loss of 2 or 3 phases is detected as well
„ Related Parameters
‹
Ground Fault Protection
This function detects the earth leakage current by calculating the sum of the three output currents. Normally it
should be 0. If the earth leakage current gets too high, the inverter output will be switched off and a GF fault
is shown on the display. The fault contact is activated.
„
Related Parameters
„ Precautions
•
It is not recommended to disable this function.
•
A Ground Fault can also be detected if contactors at the inverter output are opened when the output is still
active. Therefore, to prevent false Ground Fault detection checks the sequence and make sure that the
ouput is switched off or base blocked before opening output contactors.
Parameter
No.
Name
Factory
Setting
Change
during
Operation
Control Methods
V/f
Open
Loop
Vector
Closed
Loop
Vector
L8-07 Output open-phase protection selection 2 No A A A
Parameter
No.
Name
Factory
Setting
Change
during
Operation
Control Methods
V/f
Open
Loop
Vector
Closed
Loop
Vector
L8-09 Ground protection selection 1 No A A A
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