Speed Search Timing Chart; Speed Search Detection Level (Cn-35); Speed Search Time (Cn-36); Min. Baseblock Time (Cn-37) - TECO speecon 7200ma Instruction Manual

•The output frequency does not need to be adjusted, except in the following cases.
a. If the wiring distance between the inverter and motor is long, lower the carrier
frequency as shown below to allow less leakage current.
Wiring distance
Carrier frequency (Cn-34)
b. If there is great irregularity in speed or torque, lower the carrier frequency.
(29) Speed Search Detection Level
(30) Speed Search Time
(31) Min. Baseblock Time
(32) Speed Search V/F Curve
•The speed search function will search the speed of a frequency coasting motor
from the frequency command or max. frequency downward. And it will restart up
smoothly from that frequency or max. frequency. It is effective in situations such
as switching from a commercial power supply to an inverter without tripping
occurred.
•The timing of speed search function as shown below：
FWD(or REV) run command
Speed search command
Max output frequency
(or running frequency
while the speed search
is being performed)
Output frequency
voltage at speech search
<15kHz
<0.5 sec
Min baseblock time
ouput voltage
Fig. 27 Speed search timing chart
<30m 30m~50m 50m~100m
<10kHz
(Cn-35)
(Cn-36)
(Cn-37)
(Cn-38)
Synchronous speed dectection
speed search operation
56
>100m
<5KHz <2.5KHz
retuen to voltage at
normal operation