Yaskawa G7 Drive - Manual (Page 276)

Continuing Operation
6-
59
‹ Speed Search
The speed search function finds the actual speed of the motor that is rotating using inertia, and then starts
smoothly from that speed. When restoring power after a temporary power loss, the speed search function
switches connection from the commercial power supply, and then restarts the fan that is rotating using inertia.
„ Related Parameters
Parameter
Number
Name
Description Setting
Range Factory
Setting
Change
during
Operation
Control Methods
Display V/f
V/f
with
PG
Open
Loop
Vector
1
Flux
Vector
Open
Loop
Vector
2
b3-01
Speed search
selection (cur-
rent detection
or speed cal-
culation) Enables/disables the speed search
function for the run command and
sets the speed search method.
0:Disabled, speed calculation
1: Enabled, speed calculation
2: Disabled, current detection
3: Enabled, current detection
Speed Calculation:
When the search is started, the
motor speed is calculated and
acceleration/deceleration is
performed from the calculated
speed to the specified frequency
(motor direction is also searched).
Current Detection:
The speed search is started from
the frequency when power was
momentarily lost and the
maximum frequency, and the
speed is detected at the search
current level.
0 to 3 2 *1 No A A A No A
SpdSrch at
Start
b3-02
Speed search
operating cur-
rent (current
detection)
Sets the speed search operation
current as a percentage, taking the
Drive rated current as 100%.
Not usually necessary to set. When
restarting is not possible with the
factory settings, reduce the value.
0 to
200
100% *2 No A No A No A
SpdSrch Cur-
rent
b3-03
Speed search
deceleration
time (current
detection)
Sets the output frequency decelera-
tion time during speed search in
1-second units.
Set the time for deceleration from
the maximum output frequency to
the minimum output frequency.
0.1 to
10.0
2.0sec No A No A No No
SpdSrch Dec
Time
b3-05
Speed search
wait time
(current detec-
tion or speed
calculation) Sets the contactor operating delay
time when there is a contactor on
the output side of the Drive. When
a speed search is performed after
recovering from a momentary
power loss, the search operation is
delayed by the time set here.
0.0 to
20.0
0.2sec No A A A A A
Search Delay