Control Wiring And Terminals - Danfoss VLT AutomationDrive FC 302 Design Manual

Electrical Installation Con...

10.4 Control Wiring and Terminals

Control cables must be shielded and the shield must be
connected with a cable clamp at both ends to the metal
cabinet of the unit.
For correct grounding of control cables, see
Illustration 10.4.
PLC etc.
PLC etc.
Ground
10 10
PLC etc.
Ground
PLC etc.
Ground
100 nF
69
68
61
148
Ground Ground
Ground
Ground Ground
Ground
2
Minimum 16 mm
Equalizing cable
Ground
Drive
Ground
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VLT® AutomationDrive FC 302
1
2
3
4
Drive
5
1
Illustration 10.4 Grounding Examples
Drive
10.4.1 Control Cable Routing
2
Tie down and route all control wires as shown in
Illustration 10.5. Remember to connect the shields in a
proper way to ensure optimum electrical immunity.
•
Drive
•
3
Fieldbus connection
Connections are made to the relevant options on the
control card. See the relevant fieldbus instruction. The
cable must be tied down and routed along with other
control wires inside the unit. See Illustration 10.5.
Drive
4
Drive
68
69
5
Control cables and serial communication cables must be
fitted with cable clamps at both ends to ensure the best
possible electrical contact.
Do not use twisted cable ends (pigtails). They increase the
shield impedance at high frequencies.
If the ground potential between the drive and the PLC is
different, electric noise can occur that disturbs the entire
system. Fit an equalizing cable next to the control cable.
Minimum cable cross-section: 16 mm
If long control cables are used, 50/60 Hz ground loops are
possible. Connect 1 end of the shield to ground via a 100
nF capacitor (keeping leads short).
When using cables for serial communication, eliminate
low-frequency noise currents between 2 drives by
connecting 1 end of the shield to terminal 61. This
terminal is connected to ground via an internal RC link.
Use twisted-pair cables for reducing the differential mode
interference between the conductors.
Isolate control wiring from high-power cables.
When the drive is connected to a thermistor,
ensure that the thermistor control wiring is
shielded and reinforced/double insulated. A
24 V DC supply voltage is recommended.
2 (6 AWG).
MG38C202