Function:
This is where the user selects the minimum motor cur-
rent 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 guaran-
teeing that the load is not lost during start of a lifting/
lowering operation.
142
Leakage reactance X
L
(LEAK. REACTANCE)
Value:
0.000 - XXX,XXX
Ω
Depends on choice of mo-
tor
X
L
is the sum of rotor and sta-
tor leakage reactance.
Function:
After setting of parameters 102-106
Nameplate data
, a
number of adjustments of various parameters is made
automatically, including the leakage reactance X
L
. The
shaft performance can be improved by fine-tuning the
leakage reactance X
L
.
NOTE
Parameter 142
The leakage reactance X
L
is normally not to be changed if the name-
plate data has been set, parameters
102-106.
Description of choice:
X
L
can be set as follows:
1.
The value is stated by the motor supplier.
2.
Use the factory settings of X
L
, which the ad-
justable frequency drive itself chooses on the
basis of the motor nameplate data.
143
Internal fan control
(fan control)
Value:
Automatic (automatic)
[0]
Always switched on (always on)
[1]
Always switched off (always off)
[2]
Function:
This parameter can be set so that the internal fan is
automatically switched on and off. You can also set the
internal fan to be permanently switched on or off.
Description of choice:
If
Automatic
[0] is selected, the internal fan is switched
on or off depending on the ambient temperature and
the loading of the adjustable frequency drive.
If
Always switched on
[1] or
Always switched off
[2] is
selected, the internal fan will be permanently switched
on or off, respectively.
NOTE
If
Always switched off
[2] is selected in
combination with high switch frequency,
long motor cables or high output power,
the adjustable frequency drive's life span
is reduced. This applies in particular to
1.5, 2, 4 and 5 HP units.
144
Gain AC brake
(Gain AC brake)
Value:
1.00 - 1.50
1.30
Function:
This parameter is used to set the AC brake. Using par.
144 it is possible to adjust the size of the generator
torque that can be applied to the motor without the in-
termediate circuit voltage exceeding the warning level.
Description of choice:
The value is increased if a greater possible brake tor-
que is required. If 1.0 is selected, this corresponds to
the AC brake being inactive.
NOTE
If the value in par. 144 is increased, the
motor current will simultaneously increase
significantly when generator loads are ap-
plied. The parameter should therefore on-
ly be changed if it is guaranteed during
measurement that the motor current in all
VLT
®
2800 Series
= factory setting, () = display text, [] = value for use in communication via serial communication port
50
MG.27.A2.22 - VLT
®
is a registered Danfoss trademark