
Q7 ASD Installation and Operation Manual
115
Scan Rate
Program
⇒
Protection
⇒
Scan Rate
In the event of a momentary power outage, the output signal of the ASD will
cease. Upon restoration of power, the ASD will output a low-level signal that
will be used to determine the rotation speed of the rotor.
The low-level signal will start scanning the motor at FH and decrease until it
reaches 0.0 Hz or it matches the signal produced by the turning rotor. Once the
rate of rotation is determined, the ASD will provide the normal output to
engage the motor from its present speed.
This parameter determines the rate at which the scanning signal goes from FH
to 0.0 Hz.
Parameter Type — Numerical
Factory Default — (ASD-dependent)
Changeable During Run — No
Minimum — 0.50
Maximum — 2.50
Units — Seconds
Search (Changed From Default Parameters)
Program
⇒
Search
This function reads all of the parameters and halts at the parameters that have
been changed from the factory default setting.
Search Inertia
Program
⇒
Protection
⇒
Search Inertia
After a momentary power loss or the momentary loss of the ST-to-CC
connection, this parameter sets the time for the commanded torque to reach its
programmed setting during the automatic restart.
The Speed Search parameter must be enabled to use this feature.
Settings:
0.5 Sec.(fast)
1.0 Sec. (standard)
1.5 Sec.
2.0 Sec.
2.5 Sec.
3.0 Sec.
3.5 Sec.
4.0 Sec.
4.5 Sec.
5.0 Sec. (slow)
Parameter Type — Selection List
Factory Default — 1.0
Changeable During Run — No
Units — Seconds
Search Method
Program
⇒
Protection
⇒
Search Method
In the event of a momentary power outage, this parameter may be used to set
the starting point (frequency) of the scanning signal that is used to determine
the rotor speed or, depending on the selection, this parameter may be used to
select the method used to search for the speed of the rotor.
See Scan Rate for additional information on this parameter.
Settings:
Normal
Start from 0.0 Hz
Start from Running Frequency
Option Board (ASD-SS)
PG
Parameter Type — Selection List
Factory Default — Normal
Changeable During Run — No