LEESON SM-Plus Series Sub-Micro Inverters - Manual (Page 46)

42
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 or user 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.
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.
NOTE: 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.
P40 FREQUENCY SCALING
This scales the analog output signal at TB-30 when it is configured for a frequency output. This setting
is the output frequency that is indicated when the output signal measures 10 VDC.
Example: A 0-5 VDC signal is required to indicate 0-60 Hz. Setting this parameter to 120 Hz would
yield 10 VDC at 120 Hz, and 5 VDC at 60 Hz. If the drive only operates up to 60 Hz, the output
signal at TB-30 is limited to the desired 0-5 VDC.
P41 LOAD SCALING
This scales the analog output signal at TB-30 and /or TB-31 when they are configured for a load output.
This setting is the load (in %) that is indicated when the output signal measures 10 VDC.