7. SPECIAL ADJUSTMENT FUNCTIONS
7 - 25
7.3.2 Instantaneous power failure tough drive function
The instantaneous power failure tough drive function avoids [AL. 10 Undervoltage] even when an
instantaneous power failure occurs during operation. When the instantaneous power failure tough drive
activates, the function will increase the tolerance against instantaneous power failure using the electrical
energy charged in the capacitor in the servo amplifier and will change an alarm level of [AL. 10
Undervoltage] simultaneously. The [AL. 10.1 Voltage drop in the control circuit power] detection time for the
control circuit power supply can be changed by [Pr. PF25 SEMI-F47 function - Instantaneous power failure
detection time]. In addition, [AL. 10.2 Voltage drop in the main circuit power] detection level for the bus
voltage is changed automatically.
POINT
MBR (Electromagnetic brake interlock) will not turn off during the instantaneous
power failure tough drive.
When the load of instantaneous power failure is large, the undervoltage alarm
([AL. 10.2]) caused by the bus voltage drop may occur regardless of the set
value of [Pr. PF25 SEMI-F47 function - Instantaneous power failure detection
time].
(1) Instantaneous power failure time of the control circuit power supply > [Pr. PF25 SEMI-F47 function -
Instantaneous power failure detection time]
The alarm occurs when the instantaneous power failure time of the control circuit power supply exceeds
[Pr. PF25 SEMI-F47 function - Instantaneous power failure detection time].
MTTR (During tough drive) turns on after detecting the instantaneous power failure.
MBR (Electromagnetic brake interlock) turns off when the alarm occurs.
Control circuit
power supply
Bus voltage
Undervoltage level
(Note)
LM
(Malfunction)
[Pr. PF25]
Instantaneous power failure time of the control circuit power supply
MTTR
(During tough drive)
MBR
(Electromagnetic
brake interlock)
Base circuit
ON
OFF
ON
OFF
ON
OFF
WNG
(Warning)
ON
OFF
ON
OFF
ON
OFF
Note. Refer to table 7.1 for the undervoltage level.