VLT
®
8000 AQUA
Installation
aluminium or iron. Shield armor intended for
mechanical protection, for example, is not suitable.
■
Extra protection with regard to indirect contact
ELCB relays, multiple protective grounding or
grounding can be used as extra protection, provided
that local safety regulations are complied with.
In the case of an ground fault, a DC content
may develop in the faulty current.
Never use ELCB relays, type A, since such relays
are not suitable for DC fault currents.
If ELCB relays are used, this must be:
•
Suitable for protecting equipment with a direct
current content (DC) in the faulty current
(3-phase bridge rectifier)
•
Suitable for power-up with short charging
current to ground
•
Suitable for a high leakage current
■
RFI switch
Line supply isolated from ground:
If the adjustable frequency drive is supplied from
an isolated line source ( IT line) or TT/TN-S line
with grounded leg, it is recommended to turn off
(OFF) the RFI switch. For reference, see IEC 364-3.
In case optimum EMC performance is needed,
parallel motors are connected or the motor cable
length is above 25 m (82 ft), it is recommended
to set the switch in ON position.
In OFF position, 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 ground capacity currents
(according to IEC 61800-3).
Please also refer to the application note
VLT on
IT mains
, MN.90.CX.02. It is important to use
isolation monitors that are capable for use together
with power electronics (IEC 61557-8).
NOTE
The RFI switch is not to be operated with
AC line connected to the unit. Check that
the line supply has been disconnected
before operating the RFI switch.
NOTE
Open RFI switch is only allowed at factory-set
switching frequencies.
NOTE
The RFI switch connects the capacitors
galvanically to ground.
The red switches are operated by means of e.g. a
screwdriver. They are set in the OFF position when
they are pulled out and in ON position when they
are pushed in. Factory setting is ON.
Line supply connected to ground:
The RFI switch must be in ON position in order
for the adjustable frequency drive to comply
with the EMC standard.
MG.80.A7.22 - VLT is a registered Danfoss trademark
53
Rosewood STP ST42 General (Operation and Maintenance Manual - Part 4:
Section 6.3 Manufacturers Manuals 6.3.33 Danfoss VLT Aquadrive 8000) Vendor Manual
QP Id: VM207
Active: 03/09/2013
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