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Operation setting at fault occurrence
4.14.2 Input/output phase loss protection selection (Pr.251, Pr.872)
(1) Output phase loss protection selection (Pr.251)
If a phase loss occurs during drive unit operation (except for during zero speed control, or 12r/min or less rotation speed),
the output phase loss protection (E.LF) is activated, and drive unit trips.
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.
4.14.3 Earth (ground) fault detection at start (Pr.249)
You can choose whether to use Input/output phase loss protection or not.
Output phase loss protection is a function to stop the drive unit output if one of the three phases (U, V, W) on the drive
unit's output side (load side) is lost.
Input phase loss protection is a function to stop the drive unit output if one of the three phases (R/L1, S/L2, T/L3) on
the drive unit's input side is lost.
Parameter
number
Name Initial value Setting range Description
251
Output phase loss
protection selection
1
0 Without output phase loss protection
1 With output phase loss protection
872
Input phase loss protection
selection
0
0 Without input phase loss protection
1 With input phase loss protection
The above parameters can be set when Pr.160 Extended function display selection = "0". (Refer to page 182)
NOTE
If an input phase loss under high load continues for a long time, the converter section and capacitor lives of the drive
unit will be shorter.
If the load is light or during a stop, lost phase cannot be detected because input phase loss detection is performed
based on the fluctuation of bus voltage.
During the S-PM geared motor driving operation, lost phase cannot be detected because the drive unit has a one-rank
higher capacity compared to the motor, and the load is light for the drive unit capacity. When the load exceeds the
rated output, however, phase loss detection may be performed.
Phase loss can not be detected during regeneration load operation.
You can choose whether to use earth (ground) fault detection at start or not. Earth (Ground) fault detection is executed
only right after the start signal is input to the drive unit.
Protective function will not activate if an earth (ground) fault occurs during operation.
Parameter
number
Name Initial value Setting range Description
249
Earth (ground) fault
detection at start
0
0 Without earth (ground) fault detection
1 With earth (ground) fault detection
The above parameters can be set when Pr.160 Extended function display selection = "0". (Refer to page 182)
NOTE
As detection is executed at start, output is delayed for approx. 20ms every start. (The time required for magnetic pole detection
at start is also added to the output delay time.)
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 drive unit trips. (Refer to page 275) Even when a ground fault occurs, however, an overcurrent (E.OC3) may be detected first
to result in the output shutoff.