AC Tech SM004S, Инструкция по установке и эксплуатации

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41 SM01P
Preset Speed #6 and #7 can also be used as skip frequencies to restrict the drive from
operating at frequencies that cause vibration in the system . Refer to Parameter 38 .
P38 SKIP BANDWIDTH
The SCL/SCM drive has two skip frequencies that can be used to lock out critical
frequencies that cause mechanical resonance in the system . Once SKIP BANDWIDTH is
set to a value other than 0 Hz, the skip frequencies are enabled . When the skip frequency
function is enabled, PRESET SPEED #6 and #7 are used as the skip frequencies . SKIP
BANDWIDTH sets the range above the skip frequencies that the drive will not operate
within .
Example:
The critical frequency is 23 Hz, and it is desired to skip a frequency range of
3 Hz above and below the critical frequency (therefore the skip range is 20 to 26 Hz) .
PRESET SPEED #6 or #7 would be set to 20 Hz, and the SKIP BANDWIDTH would be
set to 6 Hz .
If the drive is running at a speed below the skip range, and it is given a speed command
that is within the skip range, the drive will accelerate to the start of the skip range (20 Hz
in the example) and run at that speed until the speed command is greater than or equal to
the "top" of the skip range . The drive will then accelerate through the skip range to the new
speed . Likewise, if the drive is running at a speed above the skip range, and it is given a
speed command that is within the skip range, the drive will decelerate to the "top" of the
skip range (26 Hz in the example) and run at that speed until the speed command is less
than or equal to the "bottom" of the skip range . The drive will then decelerate through the
skip range to the new speed .
NOTE
PRESET SPEEDS #6 and #7 can still be used as preset speeds even if they are
also being used as skip frequencies .
P39 SPEED SCALING
Parameter P39 scales the display to indicate speed in units other than frequency . This
parameter should be set to the desired display value when the drive output is 60 Hz . The
highest setting is 6500, and the highest value that can be displayed is 6553 .6 . If SPEED
SCALING is set to 0 .0, the speed scaling function is disabled and the display will indicate
frequency .
Example: A machine produces 175 parts per hour when the motor is running at 60 Hz .
Setting SPEED SCALING to 175 will calibrate the drive's display to read 175 when the
motor is running at 60 Hz . This is a linear function, so at 30 Hz the display would read
87 .5 Hz, and at 120 Hz the display would read 350 .
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