VLT
®
8000 AQUA
Installation
■
Use of emc-correct cables
Braided screened/armoured cables are recommended
to optimise EMC immunity of the control cables and
the EMC emission from the motor cables.
The ability of a cable to reduce the in- and outgoing
radiation of electric noise depends on the transfer
impedance (Z
T
). The screen of a cable is normally
designed to reduce the transfer of electric noise;
however, a screen with a lower transfer impedance
(Z
T
) value is more effective than a screen with a
higher transfer impedance (Z
T
).
Transfer impedance (Z
T
) is rarely stated by
cable manufacturers, but it is often possible to
estimate transfer impedance (Z
T
) by assessing
the physical design of the cable.
Transfer impedance (Z
T
) can be assessed on the
basis of the following factors:
-
The conductibility of the screen material.
-
The contact resistance between the individual
screen conductors.
-
The screen coverage, i.e. the physical area
of the cable covered by the screen - often
stated as a percentage value.
-
Screen type, i.e. braided or twisted pattern.
Aluminium-clad with copper wire.
Twisted copper wire or armoured steel wire cable.
Single-layer braided copper wire with varying percentage screen
coverage.
This is the typical Danfoss reference cable.
Double-layer braided copper wire.
Twin layer of braided copper wire with a magnetic,
screened/armoured intermediate layer.
Cable that runs in copper tube or steel tube.
Lead cable with 1.1 mm wall thickness.
MG.83.A2.02 - VLT is a registered Danfoss trademark
73
Содержание VLT 8000 AQUA series
Страница 29: ...VLT 8000 AQUA Introduction TYPE CODE Table Ordering form MG 83 A2 02 VLT is a registered Danfoss trademark 29 ...
Страница 52: ...VLT 8000 AQUA Mechanical dimensions MG 83 A2 02 VLT is a registered Danfoss trademark 52 ...
Страница 60: ...VLT 8000 AQUA All enclosure types VLT 8152 8652 380 480 V MG 83 A2 02 VLT is a registered Danfoss trademark 60 ...
Страница 63: ...VLT 8000 AQUA Installation MG 83 A2 02 VLT is a registered Danfoss trademark 63 ...