YASKAWA Varispeed G7 Series Instruction Manual page 302

Speed Search Selection
Set whether to enable or disable speed search at startup, and set the type of speed search (estimated speed or
current detection) using setting b3-01. To perform speed search when inputting the Run Command, set b3-01
to 1 or 3.
Search Name
Estimates the motor speed when the search
starts, and accelerates and decelerates from the
Search Method estimated speed to the set frequency. You can
also search including direction of motor rota-
tion.
External search command 1 and external
External Speed Search search command 2 become the same operation,
Command estimating the motor speed and starting the
search from the estimated speed.
Cannot be used multi-motor drives, motors two
Application Precau-
or more frames smaller than the Inverter capac-
tions
ity, and high-speed motors (130 Hz min.)
Estimated Speed Search (b3-01 = 0 or 1)
The time chart for estimated speed searches is shown below.
Search at Startup (b3-01 = 1)
The time chart when speed search at startup or external speed search command of multi-function inputs has
been selected is shown below.
OFF
Run Command
Output frequency
Output current
Minimum baseblock time (L2-03) × 0.7*
Note If the stopping method is set to coast to stop, and the Run Command turns ON in a short time,
the operation may be the same as the search in case 2.
Estimated Speed (b3-01 = 0 or 1)
ON
Start using
speed detected
1.0 s
* Lower limit set using Speed Search Wait Time (b3-05).
Fig 6.45 Speed Search at Startup (Estimated Speed)
Continuing Operation
Current Detection (b3-01 = 2 or 3)
Starts speed search from the frequency when
the temporary power loss was detected, or from
the highest frequency, and performs speed
detection at the current level during the search.
External speed search command 1:
Starts speed search from the maximum output
frequency.
External speed search command 2:
Starts speed search from the frequency refer-
ence set before the search command.
In control method without PG, the motor may
accelerate suddenly with light loads.
Set frequency
reference
b3-02
69
6-