Danfoss VLT 2800 Series Operating Instructions Manual page 27

136 Slip compensation
(SLIP COMP.)
Value:
-500 - +500% of rated slip compensation
Function:
Slip compensation is calculated automatically, on the
basis of such data as the rated motor speed n
this parameter, the slip compensation can be fine-
tuned, thereby compensating for tolerances on the
value for n . Slip compensation is only active if a
M,N
selection has been made of Speedregulation, open
loop [0] in parameter 100 Configuration and Constant
torque [1] in parameter 101 Torque characteristic.
Description of choice:
Key in a % value.
137 DC hold voltage
(DC HOLD VOLTAGE)
Value:
0 - 100% of max. DC hold voltage
Function:
This parameter is used to keep the motor (holding tor-
que) at start/stop.
Description of choice:
This parameter can only be used if a selection has
been made of DC hold in parameter 121 Start func-
tion or 122 Function at stop . To be set as a percentage
value of the max. DC hold voltage, which depends on
the choice of motor.
138 Brake cut out value
(Brake cut out)
Value:
0.5 - 132.0/1000.0 Hz
Function:
Here you can select the frequency at which the exter-
nal brake is released, via the output defined in param-
eter 323 Relay output 1-3 or 341 Digital output, terminal
46.
Description of choice:
Set the required frequency.
= factory setting, () = display text, [] = value for use in communication via serial communication port
26
VLT
139 Brake cut in frequency
(Brake cut in)
Value:
0.5 - 132.0/1000.0 Hz
100%
Function:
Here you can select the frequency at which the exter-
. In nal brake is activated; this takes place via the output
M,N
defined in parameter 323 Relay output 1-3 or 341 Dig-
ital output terminal 46.
Description of choice:
Set the required frequency.
140 Current, minimum value
(CURRENT MIN VAL)
Value:
0 % - 100 % of inverter output current
Function:
This is where the user selects the minimum motor cur-
rent running for the mechanical brake to be released.
0%
Current monitoring is only active from stop until the
point when the brake is released.
Description of choice:
This is an extra safety precaution, aimed at guaran-
teeing that the load is not lost during start of a lifting/
lowering operation.
142 Leakage reactance X
(LEAK. REACTANCE)
Value:
0.000 - XXX,XXX Ω
3.0 Hz
Function:
After setting of parameters 102-106 Nameplate data, a
number of adjustments of various parameter is made
automatically, including the leakage reactance X
shaft performance can be improved by fine-tuning the
leakage reactance X
NB!
Parameter 142 The leakage reactance X
is normally not to be changed if the name-
plate data have been set, parameters
102-106.
MG.27.A2.02 - VLT
®
2800 Series
L
Depends on choice of mo-
X is sum of rotor and stator
L
leakage reactance.
.
L
®
is a registered Danfoss trademark
3.0 Hz
0 %
tor
. The
L
L