Lenze TCF Series - Manual (Page 50)

P28 FIXED BOOST
FIXED BOOST is active only in V/Hz mode (refer to Parameter 80), and increases starting
torque by increasing the output voltage when operating below half of the base frequency,
which increases the V/Hz ratio . The factory default setting depends on HP rating, as shown
in the following table .
HP DEFAULT HP DEFAULT
0 .5 - 1 2 .0% 5 1 .2%
1 .5 - 2 1 .8% 7 .5 1 .0%
3 1 .5% 10 1 .0%
P29 ACCELERATION BOOST
ACCELERATION BOOST is active only in V/Hz mode (refer to Parameter 80), and helps
accelerate high-inertia loads . During acceleration the output voltage is increased to increase
motor torque . Once the motor reaches the new speed setpoint the boost is turned off .
P30
SLIP COMPENSATION
SLIP COMPENSATION is active only in V/Hz mode (refer to Parameter 80) and 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-4 and TB-13A (or 13D), 13B and
13C . The TB-13 terminals must be programmed as preset speed selects using Parameters
10, 11, 12 and 49 . Preset Speeds #2 and #4 are also used when the drive is in JOG mode .
Refer to Parameters 11 and 12 . Preset speeds are not available in Vector Torque mode .
NOTE
Preset speeds can operate below the frequency defined by MINIMUM
FREQUENCY (Parameter 23) . The range of adjustment for the preset speeds
is from 0 Hz to MAXIMUM FREQUENCY (Parameter 24) .
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