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îš„Setting Precautions
• When both external search commands 1 and 2 are set for the multi-function digital inputs, an OPE03
(invalid multi-function digital input selection) alarm will occur. Set either external search command 1 or
external search command 2.
• If speed search during startup is selected when using V/f control with PG or Closed Loop Vector control
the unit will start from the frequency detected by PG.
• If performing speed search using external search commands, design the control circuit so that the run com-
mand and external search command are both ON. These two commands must be kept on, at least for the
time set in parameter L2-03.
• If the Inverter output is equipped with a contactor, set the contactor operation delay time in the Speed
Search Wait Time (b3-05). The factory setting is 0.2 s. When not using a contactor, you can reduce the
search time to 0.0 s. After waiting for the speed search wait time, the Inverter starts the speed search.
• Parameter b3-02 (current detection level for search completion) is effective only when current detection
speed search is selected. When the current falls below the detection level, the speed search is supposed to
be as completed, and the motor accelerates or decelerates to the set frequency.
• If an overcurrent (OC) is detected when using speed search after power recovery, lengthen the Minimum
Baseblock Time (L2-03).
îš„Application Precautions for Speed Searches Using Estimated Speed
• When using V/f control with or without a PG, always perform stationary autotuning for line-to-line resis-
tance before using speed searches based on calculated speeds.
• When using Open Loop or Closed Loop Vector control, always perform rotational autotuning before using
speed searches based on calculated speeds.
• If the cable length between the motor and Inverter is changed after autotuning has been performed, per-
form stationary autotuning for line-to-line resistance again.
îš„Speed Search Selection
The speed search method can be selected using b3-01. If b3-01 is set to 0 the search method is speed calcula-
tion. It has to be activated by a multi-function input (H1- set to 61 or 62).
If b3-01 is set to 1, the search method is speed calculation too, but speed search is performed at every RUN
command and has not to be activated by a multifunction input.
The same is valid for setting b3-01 to 2 or 3, only the search method is current detection instead of speed cal-
culation.
Refer to the table below to see the differences of both search methods.
Search Name Speed Calculation Current Detection
Search Method
Calculates the motor speed when the search starts, and accel-
erates or decelerates from the calculated speed to the set fre-
quency. The direction of motor rotation is also detected.
Starts speed search from the frequency when the temporary
power loss was detected, or from the highest frequency, and
performs speed detection by watching the current level dur-
ing the search.
External Speed Search Com-
mand
External search command 1 and external search command 2
become the same operation calculation of the motor speed
and starting the search from the calculated speed.
External speed search command 1:
Starts speed search from the maximum output frequency.
External speed search command 2:
Starts speed search from the frequency reference set before
the search command.
Application Precautions
Cannot be used with multi-motor drives, with motors two or
more sizes smaller than the Inverter capacity, and high-speed
motors (higher than 130 Hz)
In control method without PG, the motor may accelerate sud-
denly with light loads.
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