Mitsubishi FR-A740-00023-EC, Instruction Manual

Page: 274 / 474

264
Operation setting at alarm occurrence
4.18.3 Input/output phase failure protection selection (Pr. 251, Pr. 872)
(1) Output phase failure protection selection
(Pr. 251)
⋅ When Pr. 251 is set to "0", output phase failure protection (E.LF) becomes invalid.
(2) Input phase failure protection selection (Pr. 872)
⋅
When Pr. 872 is set to "1", input phase failure protection (E.ILF) is provided if a phase failure of one phase among
the three phases is detected for 1s continuously.
4.18.4 Overspeed detection (Pr. 374)
4.18.5 Encoder signal loss detection (Pr. 376)
* Setting can be made only when the FR-A7AP is mounted.
You can disable the output phase failure protection function that stops the inverter output if one of the inverter
output side (load side) three phases (U, V, W) opens.
The input phase failure protection function of the inverter input side (R/L1, S/L2, T/L3) can be made valid.
Parameter
Number
Name Initial Value Setting Range Description
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
REMARKS
If an input phase failure has occurred when Pr. 872 = "1" (input phase failure protected) and a value other than "0" (power failure
stop function valid) is set in Pr. 261 , input phase failure protection (E.ILF) is not provided but power-failure deceleration is made.
CAUTION
⋅
When an input phase failure occurs in the R/L1 and S/L2 phases, input phase failure protection is not provided but the
inverter output is shut off.
⋅
If an input phase failure continues for a long time, the converter section and capacitor lives of the inverter will be shorter.
♦
Parameters referred to
♦
Pr. 261 Power failure stop selection Refer to page 258
Parameter
Number
Name Initial Value Setting Range Description
374 Overspeed detection level 140Hz
0 to 400Hz
When the motor speed reaches or exceeds
the speed set in
Pr. 374 during encoder
feedback control, real sensorless vector
control, or vector control, over speed (E.OS)
occurs and stops the inverter output.
When the encoder signal is lost during encoder feedback control, orientation control, or vector control, signal loss
detection (E.ECT) is activated to stop the inverter output.
Parameter
Number
Name Initial Value Setting Range Description
376
Encoder signal loss
detection enable/disable
selection
0
0
Signal loss detection is invalid
1 Signal loss detection is valid
ALM
Motor speed *
Time
E.OS
Coast to stop
ON
Pr. 374
* The output frequency and Pr. 374 are compared during
real sensorless vector control.
V/F V/F V/F Magnetic flux Magnetic flux Magnetic flux Vector Vector Vector