Input/Output Phase Loss Protection Selection (Pr. 251, Pr. 872); Earth (Ground) Fault Detection At Start (Pr. 249) - Mitsubishi Electric FR-D700 Instruction Manual

4.13.2 Input/output phase loss 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 loss protection function that trips the inverter if one phase of the inverter output side
(load side) three phases (U, V, W) is lost.
The input phase loss protection function of the inverter input side (R/L1, S/L2, T/L3) can be made invalid.
Parameter
Name
Number
Output phase loss
251
protection selection
Input phase loss protection
872 ∗
selection
The above parameters can be set when Pr. 160 Extended function display selection = "0". (Refer to page 157)
∗ Available only for the three-phase power input specification model.
(1) Output phase loss protection selection (Pr. 251)
When Pr. 251 is set to "0", output phase loss protection (E.LF) becomes invalid.
(2) Input phase loss protection selection (Pr. 872)
When Pr. 872 is set to "1", input phase loss protection (E.ILF) is provided if a phase loss of one phase among the three
phases is detected for 1s continuously.
NOTE
If an input phase loss continues for a long time, the converter section and capacitor lives of the inverter will be
shorter.
As phase loss is detected according to the bus voltage change, it can not be detected if the load is light. Unbalanced
phase-to-phase voltage of the three-phase power input may also be 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 setting after parameter copy.

4.13.3 Earth (ground) fault detection at start (Pr. 249)

You can choose whether to make earth (ground) fault detection at start valid or invalid. Earth (Ground) fault detection is
executed only right after the start signal is input to the inverter.
Protective function will not activate if an earth (ground) fault occurs during operation.
Parameter
Name
Number
Earth (ground) fault
249
detection at start
The above parameters can be set when Pr. 160 Extended function display selection = "0". (Refer to page 157)
NOTE
As detection is executed at starting, output is delayed for approx. 20ms every starting.
If an earth (ground) fault is detected with "1" set in Pr. 249, output side earth (ground) fault overcurrent (E.GF) is detected and
the inverter trips. (Refer to page 252)
If the motor capacity is smaller than the inverter capacity when using the FR-D740-120 or more, earth (ground) fault detection
may not be provided.
Operation setting at fault occurrence
Initial Value Setting Range
0
1
1
0
1
1
Initial Value Setting Range
0
1
1
Description
Without output phase loss protection
With output phase loss protection
Without input phase loss protection
With input phase loss protection
Description
Without earth (ground) fault detection
With earth (ground) fault detection
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