Danfoss VLT 2800 Design Manual page 77

Programming
138 Brake cut out value
Value:
0.5 - 132.0/590.0 Hz
Function:
Select the frequency at which the external brake is
released, via the output defined in parameter 323 Relay
output 1-3 or 341 Digital output, terminal 46.
Description of choice:
Set the required frequency.
139 Brake cut in frequency
Value:
0.5 - 132.0/590.0 Hz
Function:
Select the frequency at which the external brake is
activated; this takes place via the output defined in
parameter 323 Relay output 1-3 or parameter 341 Digital
output terminal 46.
Description of choice:
Set the required frequency.
140 Current, minimum value
Value:
0 % - 100 % of inverter output current
Function:
Select the minimum motor current running for the
mechanical brake to be released. 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 guaranteeing
that the load is not lost during start of a lifting/lowering
operation.
142 Leakage reactance X
Value:
0.000 -
XXX,XXX Ω
X is sum of rotor and stator leakage
L
Function:
After setting of parameters 102-106 Nameplate data, a
number of adjustments of various parameter is made
automatically, including the leakage reactance X
performance can be improved by fine-tuning the leakage
reactance X .
L
Description of choice:
X can be set as follows:
L
•
The value is stated by the motor supplier.
•
Use the factory settings of X
frequency converter itself chooses on the basis of
the motor nameplate data.
MG27E402
Design Guide
3.0 Hz
3.0 Hz
0 %
L
Depends on choice of motor
reactance.
. The shaft
L
which the
L
Danfoss A/S © Rev. May/2014 All rights reserved.
NOTICE
Do not change parameter 142 The leakage reactance X
the nameplate data is set in parameters 102-106.
143 Internal fan control
Value:
Automatic (automatic)
Always switched on (always on)
Always switched off (always off)
Function:
This parameter can be set so that the internal fan is
automatically switched on and off. It is also possible to set
the internal fan to be permanently switched on or off.
Description of choice:
If [0] Automatic is selected, the internal fan is switched on
or off depending on the ambient temperature and the
loading of the frequency converter.
If [1] Always switched on or [2] Always switched off is
selected, the internal fan is permanently switched on or
off.
CAUTION
If [2] Always switched off is selected with high switch
frequency, long motor cables or high output power, the
life span of the frequency converter is reduced.
144 Gain AC brake
Value:
1.00 - 1.50
Function:
This parameter is used to set the AC brake. Using
parameter 144 it is possible to adjust the size of the
generator torque that can be applied to the motor without
the intermediate circuit voltage exceeding the warning
level.
Description of choice:
The value is increased if a higher possible brake torque is
required. If 1.0 is selected, this corresponds to the AC
brake being inactive.
WARNING
If the value in parameter 144 is increased, the motor
current simultaneously increases significantly when
generator loads are applied. The parameter should
therefore only be changed if it is guaranteed during
measurement that the motor current in all operating
situations does not exceed the maximum permitted
current in the motor. The current cannot be read out
from the display.
if
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[0]
4 4
[1]
[2]
1.30
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