
Commissioning
8200SHB0199
5-11
3.Set V
min
boost (C016). Load-dependent boost of the motor voltage in the field frequency range below the V/f-rated
frequency. C016 acts as gain factor of the auto-boost function.
Adjustment
Ingeneral, anadjustmentis not necessary. An optimisation canbe advantageous:
For drives with very high starting torques:
A Operate the motor under load.
B Select the frequency setpoint.
C Increase V
min
until the required motor current (torque) occurs.
If the setting of V
min
is too high, a positive-feedback effect can occur and activate the TRIP
”overcurrent” (OCx).
For drives with square load torques (fans,pumps):
A Operate the motor under load.
B Select the frequency setpoint.
C Adapt V
min
until the motor is running steadily and smoothly over the whole frequency range.
If the setting of V
min
istoohigh, the TRIP”overcurrent” (OCx)canbe activatedandleadtoan
excessive motor temperature.
For drives with special motors:
A Operate the motor under load.
B Select the frequency setpoint.
C Increase V
min
until the required motor current (torque) occurs.
If the setting of V
min
is too high, a positive-feedback effect can occur and activate the TRIP
”overcurrent” (OCx).
D Check the current consumption during idle running when no load is applied.
4.Set the slip compensation
Rough setting according to motor data:
(C021).
s
n
Nsyn
n
r
n
Nsyn
100 %
n
Nsyn
f
dr
60
p
s Slipconstant (C021)
n
Nsyn
Synchronous motor speed [min
-1
]
n
r
Rated speed to motor nameplate [min
-1
]
f
dr
Rated frequency to motor nameplate [Hz]
p No. of pole pairs(1, 2, 3, ...)
Precise setting:
Correct C021 until no load-dependent speed drop occurs in the required speed range between
idle running and max. motor load.
If the values under C021 are too high, the drive may become instable (overcompensation).
Inthe fieldfrequencyrange between5 Hz ... 50 Hz (87 Hz)the deviationof the ratedspeedis
$ 1 % (guide value). In field-weakening operation, the fault increases.
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