Mitsubishi Electric FR-D720S SC EC, Instruction Manual

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Parameter Operation setting at alarm occurrence
FR-D700 SC EC 6 - 141
6.12.2 Input/output phase failure protection selection (Pr. 251, Pr. 872)
You can choose whether to make Input/output phase loss protection valid or invalid.
You can disable the output phase failure function that stops the inverter output if one of the in-
verter output side (load side) three phases (U, V, W) opens.
The protection function for the input phases (R/L1, S/L2, T/L3) can be deactivated.
The above parameters can be set when Pr. 160 = 0.
Available only for the three-phase power input specification model.
Output phase failure protection selection (Pr. 251)
●
If phase loss occurs during inverter running (except for during DC brake operation, or output
frequency is 1Hz or less), output phase loss protection (E.LF) activates, and inverter trips.
●
When Pr. 251 is set to "0", output phase failure protection (E.LF) becomes invalid.
Input phase failure protection selection (Pr. 872)
When Pr. 872 is set to "1" (initial value), input phase failure protection (E.ILF) is provided if a
phase failure of one phase among the three phases is detected for 1s continuously.
Pr.
No.
Name
Initial
Value
Setting
Range
Description Parameters referred to
Refer to
Section
251
Output phase failure
protection selection
1
0 Without output phase failure protection
—
1 With output phase failure protection
872
Input phase failure
protection selection
0
0 Without input phase failure protection
1 With input phase failure protection
NOTES
If an input phase failure continues for a long time during inverter operation, the converter
section and capacitor lives of the inverter will be shorter.
If the load is light or during a stop, lost phase cannot be detected because detection is per-
formed based on the fluctuation of bus voltage. Also, if the power supply voltage is imbal-
anced, phase loss is less likely detected.
Phase loss can not be detected during regeneration load operation.
If parameter copy is performed from single-phase power input specification model to three-
phase power input specification model, Pr. 872 setting may be changed. Check Pr. 872 set-
ting after parameter copy.