RFI switch
Mains supply isolated from earth:
If the frequency converter is supplied from an isolated
mains source (IT mains) or TT/TN-S mains with groun-
ded leg, the RFI switch is recommended to be turned
off (OFF)
1)
. For further 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, it is recommended to set the switch in ON
position.
In OFF position, the internal RFI capacities (filter ca-
pacitors) between the chassis and the intermediate
circuit are cut off to avoid damage to the intermediate
circuit and to reduce the earth capacity currents (ac-
cording 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).
1)
Not possible with 5042-5602, 525-690 V units.
NB!
The RFI switch is not to be operated with
mains connected to the unit. Check that
the mains supply has been disconnected
before operating the RFI switch.
NB!
Open RFI switch is only allowed at factory
set switching frequencies.
NB!
The RFI switch connects the capacitors
galvanically to earth.
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.
Mains supply connected to earth:
The RFI switch must be in ON position in order for the
frequency converter to comply with the EMC standard.
Position of RFI switches
Bookstyle IP 20
VLT 5001 - 5006 200 - 240 V
VLT 5001 - 5011 380 - 500 V
Compact IP 20/NEMA 1
VLT 5001 - 5006 200 - 240 V
VLT 5001 - 5011 380 - 500 V
VLT 5001 - 5011 525 - 600 V
Compact IP 20/NEMA 1
VLT 5008 200 - 240 V
VLT 5016 - 5022 380 - 500 V
VLT 5016 - 5022 525 - 600 V
VLT
®
5000 Design Guide
MG.52.B2.02 - VLT
®
is a registered Danfoss trademark
81
Electrical installation
