Danfoss VLT AQUA High Power Operating Instructions Manual page 52

3. How to Install
In the case of an earth fault, a DC content may develop in the faulty current.
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.
See also the section
3
3.6.5. 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)
ance is 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 required with 525-600/690 V drives; therefore not possible.
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
isolation monitors that are capable for use together with power electronics (IEC 61557-8).
3.6.6. Torque
When tightening all electrical connections it is
very important to tighten with the correct tor-
que. Too low or too high torque results in a
bad electrical connection. Use a torque
wrench to ensure correct torque
Enclosure
D1, D2, D3 and D4
E1 and E2
Table 3.4: Torque for terminals
52
Special Conditions
1) via par. 14-50. For further reference, see IEC 364-3. In case optimum EMC perform-
Terminal
Mains
Motor
Load sharing
Brake
Mains
Motor
Load sharing
Brake
MG.20.P1.02 - VLT
VLT AQUA High Power Operation Instructions
in the relevant Design Guide.
VLT on IT mains, MN.90.CX.02
Illustration 3.79: 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)
®
is a registered Danfoss trademark
. It is important to use
Bolt size
M10
M8
M10
M8