Lenze SCD Series - Manual (Page 46)

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SPEED # TB - 13A TB - 13B TB - 13C
1 CLOSED OPEN OPEN
2 OPEN CLOSED OPEN
3 OPEN OPEN CLOSED
4 CLOSED CLOSED OPEN
5 CLOSED OPEN CLOSED
6 OPEN CLOSED CLOSED
7 CLOSED CLOSED CLOSED
NOTE 2: When a TB-13 terminal is programmed for a function other than a preset speed select, it is
considered OPEN for the table above.
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. See Parameter 38 below.
P38 SKIP BANDWIDTH
The SCD 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 0.0 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 6.0 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 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
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.