Lenze 13466147 EDBSM01 v19 EN
43
Commissioning 4
P30
SLIP COMPENSATION
SLIP COMPENSATION is used to counteract changes in motor speed (slip) caused by changes in
load. In a standard AC induction motor, the shaft speed decreases as load increases, and increases
as load decreases. By increasing or decreasing the output frequency in response to an increasing or
decreasing load, the slip is counteracted and speed is maintained. Most standard NEMA B motors
have a 3% slip rating.
P31 - P37 PRESET SPEED #1 - #7
Preset speeds are activated by contact closures between TB-11 and TB-13A, 13B, and 13E. The TB-13
terminals must be programmed as preset speed selects using Parameters 10-12.
NOTE
Preset speeds can operate below the frequency defined by the Minimum Frequency
parameter (Parameter 23).
Refer to the table below for activation of the preset speeds using the TB-13 terminals:
SPEED #
TB - 13A
TB - 13B
TB - 13E
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
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. 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.
