Danfoss VLT AutomationDrive FC 300 Design Manual page 119

FC 300 Design Guide
If ELCB relays are used, local regulations must be observed. Relays must be suitable for protection of 3-phase equipment with a bridge rectifier and for
a brief discharge on power-up.
Special Conditions
See also the section
6.5.5. RFI Switch
Mains supply isolated from earth
If the frequency converter is supplied from an isolated mains source (IT mains, floating delta and grounded delta) or TT/TN-S mains with grounded leg,
the RFI switch is recommended to be turned off (OFF)
needed, parallel motors are connected or the motor cable length is above 25 m, it is recommended to set par. 14-50 to [ON].
1) Not available for 525-600/690 V drives.
In OFF, the internal RFI capacities (filter capacitors) between the chassis and the intermediate circuit are cut off to avoid damage to the intermediate
circuit and to reduce the earth capacity currents (according to IEC 61800-3).
Please also refer to the application note
power electronics (IEC 61557-8).
6.5.6. Torque
When tightening all electrical connections it is very important to tighten
with the correct torque. Too low or too high torque results in a bad elec-
trical connection. Use a torque wrench to ensure correct torque
Enclosure
D1, D2, D3 and D4
E1 and E2
Table 6.5: Torque for terminals
6.5.7. Shielded Cables
It is important that shielded and armoured cables are connected in a proper way to ensure high EMC immunity and low emissions.
in the Design Guide.
1) via par. 14-50. For further reference, see IEC 364-3. In case optimum EMC performance is
VLT on IT mains, MN.90.CX.02
. It is important to use isolation monitors that are capable for use together with
Terminal
Mains
Motor
Load sharing
Brake
Mains
Motor
Load sharing
Brake
MG.33.BA.02 - VLT ® is a registered Danfoss trademark
Illustration 6.46: Always use a torque wrench to tighten the
bolts.
Torque
19 Nm (168 in-lbs)
9.5 (84 in-lbs)
19 NM (168 in-lbs)
9.5 (84 in-lbs)
6. How to Install
Bolt size
M10
M8
M10
M8
6
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