YASKAWA CIMR-ZU A Series Programming Manual page 33

The output frequency is reduced if the current is higher than the level in b3-02. When the current falls below b3-02, the motor
speed is assumed to be found and the drive starts to accelerate or decelerate to the frequency reference.
Run command
Output
frequency
Output
current
Min. Baseblock Time (L2-03)
<1> The wait time for Speed Search (b3-05) determines the lower limit.
Notes on Usin Speed Estimation Speed Searc
• Perform Rotational Auto-Tuning for V/f Control (T1-01 = 3) prior to using Speed Estimation in V/f Control and perform
Stationary Auto-Tuning for Line-to-Line Resistance (T1-01 = 2) again if the there is a change in the cable length between
the drive and motor.
• Use Current Detection to search for speeds beyond 200 Hz if the application is running multiple motors from the same drive
or if the motor is considerably smaller than the capacity of the drive.
• Speed Estimation may have trouble finding the actual speed if the motor cable is very long. Use Current Detection in these
instances.
• Use Current Detection instead of Speed Estimation when operating motors smaller than 1.5 kW because Speed Estimation
might not be able to detect the speed or rotation of these smaller motors, in which case Speed Estimation would stop the
motor.
• Use Short Circuit Braking instead of Speed Search when using OLV/PM with a long motor cable.
• Use Short Circuit Braking instead of Speed Search when attempting to find the speed of a motor coasting faster than 200
Hz in OLV/PM.
Speed Searc Acti ation
Speed Search can be activated using any of the methods 1 through 5 described below. The Speed Search type must be selected
in parameter b3-24 independent of the activation method.
Method 1. Automatically activate Speed Search with every Run command. External Speed Search commands are ignored.
Method 2. Activate Speed Search using the digital input terminals.
Use the input functions for H1-
Settin Description
External Search
61
Command 1
External Search
62
Command 2
To activate Speed Search by a digital input, the input must be set together with the Run command or the Run command must
be entered after giving the Speed Search command.
Method 3. After automatic fault restart.
When the number of maximum fault restarts in parameter L5-01 is set higher than 0, the drive will automatically perform
Speed Search as specified by b3-24 following a fault.
Method 4. After momentary power loss.
Decelerates at the Speed
Search decel time set to b3-03
ON
OFF
Starts at the speed
speed that was detected
1.0 s
<1>
Fi ure 1 1
in
Table 1.7.
able 1 7 Speed Searc Acti ation by Di ital Inputs
Closed: Activate Current Detection Speed Search from the
maximum output frequency.
Closed: Activate Current Detection Speed Search from the
frequency reference.
Waits twice as long as L2-04
Frequency reference
set to the drive
b3-02 (Speed search operation current)
Speed Searc at Start
b 2
1 2 b Application
b 2 1
Activate Speed Estimation
Speed Search
1