Speed Search - YASKAWA Varispeed E7 Instruction Manual And Parameter Description

Speed Search

The speed search function finds the actual speed of a motor that is coasting without control, and then starts
smoothly from that speed. It is also activated after momentary power loss detection when L2-01 is set to
enabled.
Related Constants
Con-
stant Name
Number
Speed search selection (current
b3-01
detection or speed calculation)
Speed search operating current
b3-02
(current detection)
Speed search deceleration time
b3-03
(current detection)
Speed search wait time (current
b3-05
detection or speed calculation)
Bi-directional speed search selec-
b3-14
tion
L2-03 Min. baseblock time
L2-04 Voltage recovery time
* Factory settings depend on Inverter capacity. (The values shown are for a 200 V Class Inverter for 0.4 kW.)
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Description
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 or the maximum frequency,
and the speed is detected when the set search current
level is reached.
Sets the speed search operation current as a percentage,
taking the Inverter rated current as 100%.
Usually not necessary to set. When restarting is not possi-
ble with the factory settings, reduce the value.
Sets the output frequency deceleration time during speed
search.
Sets the time for deceleration from the maximum output
frequency to the minimum output frequency.
When a speed search is performed after recovering from a
momentary power loss, the search operation is delayed for
the time set here.
If e.g. a contactor is used at the output side of the inverter
set this constant to the contactor delay time or more.
Can be used to turn off the bidirectional capabilities of the
speed calculation form of speed search. Then speed search
will only be performed in the last known direction.
Sets the Inverter's minimum baseblock time, when the
inverter is restarted after power loss ridethrough.
Set the time to approximately 0.7 times the motor time
constant.
If an overcurrent or undercurrent occurs when starting a
speed search or DC injection braking, increase the set val-
ues.
Sets the time required to return the Inverter output voltage
to normal voltage at the completion of a speed search.
Sets the time required to recover from 0 V to the maximum
voltage.
Automatically Restart
Change
Setting Factory during Access
Range Setting Opera- Level
tion
0 to 3 No
2
0 to
120% No
200
0.1 to
2.0 s No
10.0
0.0 to
0.2 s No
20.0
0 or 1 1 No
0.1 to 5.0 No
0.1 s
0.0 to
*
No
0.3 s
5.0
A
A
A
A
A
A
A
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