LEESON SM Series Sub-Micro Inverters - Manual (Page 44)

40
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 6.0 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
the 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
This 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 the
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, and at 120 Hz, the display would
read 350.
NOTES:
1: If the displayed value will exceed 999, the value is shown in two parts. For example, if the
displayed value is 1800, the display will indicate this by toggling between “1- -” and “800’.
2. If SPEED SCALING is set such that the maximum displayable value (6553.6) is exceeded,
the display will flash “9999” to indicate that the value is out of range. For example, if SPEED
SCALING is set to 6000, the drive will display 6000 when it is running at 60 Hz. If the speed
is increased past 65.5 Hz (at 65.5 Hz, the scaled value would be 6550), the display will flash
“9999” because a scaled value above 6553.6 cannot be displayed.
P42 ACCEL / DECEL #2
This parameter sets the second acceleration and deceleration rate of the drive, which can be activated
using terminals TB-13A, 13B, or 13E (Parameter 10, 11, or 12).