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 shar-
ing 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]
2803-
2875
Power mains brake 0.5-0.6
Earth 2-3
2880-
2882, 2840
PD2
Power mains brake 1.2-1.5
Earth 2-3
Control of mechanical brake
In lifting/lowering applications you need to be able to
control an electromagnetic brake. The brake is con-
trolled 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 convert-
er 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 under-
neath the protective plate on the front of the frequency
converter. Remove the protective plate by pulling it
downwards (see drawing).
VLT
®
2800 Series
MG.27.A2.02 - VLT
®
is a registered Danfoss trademark 71
Installation
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