VLT
®
2800 Series
Installation
■
Load sharing
Load sharing provides the facility to connect several
frequency converters
’
DC intermediate circuits.
This requires that the installation is extended using
extra fuses and AC coils (see drawing below).
For load sharing parameter 400
Brake function
must be set to
Load sharing
[5].
Use 6.3 mm Faston Plugs for DC (Load Sharing).
Contact Danfoss or see instructions no. MI.50.NX.02
for further information.
No. 88
89
Loadsharing
-
+
Note that voltage levels of up to 850 V DC
may occur between terminals 88 and 89.
■
Tightening Torque, Power Terminals
Power and earth terminals must be tightened
with the following torques:
VLT
Terminals
Torque [Nm]
Power mains brake
0.5-0.6
2803-
2875
Earth
2-3
Power mains brake
1.2-1.5
2880-
2882
Earth
2-3
■
Control of mechanical brake
In lifting/lowering applications you need to be able
to control an electromagnetic brake. The brake
is controlled using a relay output or digital output
(terminal 46). The output must be kept closed
(voltage-free) for the period of time during which the
frequency converter is not able to
’
support
’
the motor,
for example due to the load being too great. Select
Mechanical brake control
in parameter 323 or 341
for applications with an electromagnetic brake.
When the output frequency exceeds the brake cut
out value set in par. 138, the brake is released
if the motor current exceeds the preset value in
parameter 140. The brake is engaged when the
output frequency is less than the brake engaging
frequency, which is set in par. 139.
If the frequency converter is placed at alarm status
or in an overvoltage situation the mechanical
brake is cut in immediately.
NB!:
This application is only for lifting/lowering
without a counterbalance.
■
Access to control terminals
All terminals to the control cables are located
underneath the protective plate on the front of the
frequency converter. Remove the protective plate
by pulling it downwards (see drawing).
MG.28.E9.02 - VLT is a registered Danfoss trademark
53
