Tightening Torque, Power Terminals; Calculation Of Brake Resistance; Access To Control Terminals; Electrical Installation, Control Circuitry - Danfoss VLT 2800 Series General Information Manual

Note that voltage levels of up to 850 V DC
may occur between terminals 88 and 89.

Tightening Torque, Power Terminals

Power and ground terminals must be tightened with
the following torques:
VLT Terminals
2803- Power AC line brake
2875 Ground
2880- Power AC line brake
2882, 2840 Ground
PD2

Calculation of brake resistance

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 variable frequency
drive 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.
When stopping the brake is engaged when the output
frequency is less than the brake engaging frequency,
which is set in par. 139.
If the variable frequency drive is placed at alarm status
or in an overvoltage situation the mechanical brake is
cut in immediately.
®
MG.27.A2.22 - VLT is a registered Danfoss trademark
Torque [Nm]
0.5-0.6
2-3

Access to control terminals

1.2-1.5
All control terminals are located underneath the pro-
2-3
tective plate on the front of the adjustable frequency
drive. Remove the protective plate by sliding it down-
wards (see drawing).

Electrical installation, control circuitry

®
VLT 2800 Series
NOTE
This application is only for lifting/lowering
without a counterbalance.
NOTE
Using unshielded/unarmored cable may
not comply with some EMI/RFI require-
ments.
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