Danfoss VLT AAF00x, Инструкция по эксплуатации

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4.5.2 Grounding
The following basic issues need to be considered when
installing an active filter so as to obtain electromagnetic
compatibility (EMC).
•
Safety grounding: Please note that the active
filter has leakage current and must be grounded
appropriately for safety reasons. Always follow
local safety regulations.
•
High-frequency grounding: Keep the ground wire
connections as short as possible.
Connect the different ground systems at the lowest
possible conductor impedance. The lowest possible
conductor impedance is obtained by keeping the
conductor as short as possible and by using the greatest
possible surface area. The metal cabinets of the different
devices are mounted on the cabinet rear plate using the
lowest possible HF impedance. This prevents having
different HF voltages for the individual devices and
prevents the risk of radio interference currents running in
connection cables that may be used between the devices,
as radio interference is reduced. In order to obtain a low
HF impedance, use the fastening bolts of the devices as HF
connections to the rear plate. It is necessary to remove
insulating paint and the like from the fastening points.
EARTH
TERMINALS
13
0B
B7
39
.1
0
Figure 4.27 Example of Ground Terminal Position
4.5.3 Extra Protection (RCD)
ELCB, RCD, GFCI relays or multiple protective grounding
are often used as extra protection, or needed to provide
compliance with local safety regulations. In case of a
ground fault, a DC component may develop in the fault
current. If ELCB relays are used, local regulations must be
observed. To ensure effective protection and unintended
tripping of protective relays, all relays must be suitable for
protection of 3-phase equipment with active current inlet
and for a brief discharge during power-up. It is
recommended to use a type with adjustable trip amplitude
and time characteristics. Select a current sensor with
sensitivity of more than 200mA and not less than 0.1
second operation time.
4.5.4 RFI Switch
Line power supply isolated from ground
If the active filter is supplied from an isolated line power
source (IT line power, floating delta and grounded delta) or
TT/TN-S line power with grounded leg, the RFI switch is
recommended to be turned off (OFF) 1) via
14-50 RFI Filter
on the unit. For further reference, see IEC 364-3. In OFF,
the internal RFI capacities between the chassis and the
intermediate circuit are cut off to avoid damage to the
intermediate circuit and to reduce the ground capacity
currents (according to IEC 61800-3). Please also refer to the
application note VLT on IT line power, MN.90.CX.02. It is
important to use isolation monitors that are capable for
use together with power electronics (IEC 61557-8).
4.5.5 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 electrical connection. Use
a torque wrench to ensure correct torque. Below is the
tightening torque required for the line power terminal:
Frame size Torque Bolt size
D 19Nm M10
E 19Nm M10
How to Install VLT Active Filter AAF 00x
MG.90.V2.22 - VLT
®
is a registered Danfoss trademark 4-21
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