Filter
Top Products
102
Automatic restart (Pr. 57, Pr. 58)
<Setting>
Refer to the above figures and following table to set the corresponding parameters.
(1) To make automatic restart after instantaneous power failure valid
Restart function after instantaneous power failure is made valid by setting a value other than "9999" in Pr. 57
"restart coasting time".
Time set in this Pr. 57 is the control start waiting time from power restoration to automatic restart.
(2) Selection of whether speed search is used or not (Pr. 162 "automatic restart after instantaneous power failure
selection")
Smooth start at power restoration is available as required only during vector control without encoder and V/F control.
Parameter
Number
Setting Description
57
0 0.1s coasting time This setting may be used without problem during vector control.
0.1 to 5s
Waiting time for inverter-triggered restart after power is restored from an instantaneous power failure.
(Set this time between 0.1s and 5s according to the magnitude of the moment (J) of inertia of the
load and torque.)
9999 Without restart
162
0
With speed search
Speed search is made after detection of an instantaneous power failure.
1
Without speed search
Independently of the motor coasting speed, the output voltage is gradually increased with the speed
kept as preset, i.e. a reduced voltage starting system.
10
Speed search is made on startup. The motor starts running at the speed detected by the encoder
under vector control.
58 0 to 60s
Normally the motor may be run with the factory settings, but restart or voltage cushion time is adjustable
according to the load (moment of inertia, torque) magnitude using Pr. 58, Pr. 163, or Pr. 164.
Also the output frequency is reduced when the current flow exceeds the Pr. 165 setting.
Invalid for vector control.
163 0 to 20s
164 0 to 100%
165 0 to 200%
CAUTION
1. With speed search (Pr. 162 = "0") under V/F control
• When the inverter capacity is two rank or more larger than the motor capacity when Pr. 162 = "0"
(with speed search), the inverter may not start due to overcurrent (OCT) alarm.
• Searchable speed is 3000r/min or less.
• Speed is regarded as 0r/min when the search speed is 150r/min or less.
• DC injection brake is applied for a moment at speed detection. Therefore speed may decrease if the
inertia is small.
2. The restart coasting time in Pr. 57 does not include the speed search time (300ms maximum).
There is no delay time due to speed search when speed search is not made or vector control is
exercised. (excluding the inverter starting time)
3. If two or more motors are connected to one inverter, the inverter functions abnormally. (The inverter
does not start smoothly.)
4. When restart operation is selected, UVT and IPF among the alarm output signals are not output at
occurrence of an instantaneous power failure.
5. The SU and FU signals are not output during restart but are output after the restart cushion time has elapsed.
CAUTION
z When automatic restart after instantaneous power failure has been selected, the motor and machine
will start suddenly (after the restart coasting time has elapsed) after occurrence of an instantaneous
power failure. Stay away from the motor and machine.
When you have selected automatic restart after instantaneous power failure, apply the supplied
CAUTION seals, provided for the Instruction Manual (basic), in easily visible places.
z The motor coasts to a stop as soon as the start signal is turned off or is pressed during
automatic restart cushion time.
Related parameters
• Setting of alarm output signal for executing automatic restart after instantaneous power failure ⇒ Pr. 65 "retry selection" (Refer to page 109.)
REMARKS
• Recommended settings for Pr. 57 during V/F control is 0.5s for 1.5K, 1.0s for 2.2 to 7.5K, and
3.0s for 11K or more.
• The setting value does not include resetting time of the inverter.
STOP
RESET