4.5 Electrical Installation
4.5.1 Power Connections
Cabling and fusing
NOTE!
Cables General
All cabling must comply with national and local
regulations on cable cross-sections and ambient
temperature. UL applications require 167°F [75
°
C] copper
conductors. 7167°F [75°C] and 194°F [90
°
and 90
°
C]
copper conductors are thermally acceptable for use in non-
UL applications.
The power cable connections are situated as shown below.
The AC line input connections are fitted to the line power
switch if this is included. Dimensioning of the cable cross-
section must be done in accordance with the filter current
rating including skin and proximity effects, derating and
local legislation.
The line power supply must be connected to terminals 91,
92 and 93. Ground is connected to the terminal to the
right of terminal 93.
Terminal No.
Function
91, 92, 93
94
Line power R/L1, S/L2, T/L3
Ground
The conductor predominantly carries currents of high
frequencies so the current distribution is not evenly
dispersed throughout the conductor cross-section. This is
due to two independent effects known as skin effect and
proximity effect. Both effects make derating necessary and,
consequently, the line power wire of the active filters must
be rated at a higher current than the filter rating itself.
NOTE!
It is insufficient to rate the power cable for the filter
current rating alone due to skin and proximity effects.
The required derating is calculated as two separate factors:
one for the skin effect and one for the proximity effect.
The skin factor depends on the conduction frequency,
cable material and cable dimensions. The proximity effect
depends on the number of conducts, diameters and the
distance between the individual cables.
The optimized line power wire is:
•
Copper wires
•
Single conducts
•
Bus bars
The reason for this is that copper has a lower skin effect
factor than aluminum. Bus bars have a greater surface area
compared to cables, which also reduces the skin effect
factor. The proximity effects of single conductions are
negligible.
The following cables specifications take both skin and
proximity effects into account:
Filter
Min CU wire
Min ALU wire
Max wire
190A
70mm
2
(2/0)
95mm
2
(3/0)
2*150mm
2
(2*300MCM)
250A
120mm
2
(4/0)
150mm
2
(300MCM)
4x240mm
2
(4x500MCM)
310A
240 mm
2
(500MCM)
2*95mm
2
(2*3/0)
4x240mm
2
(4x500MCM)
400A
2*95mm
2
(2*3/0)
2*150mm
2
(2*300MCM)
4x240mm
2
(8x900MCM)
Table 4.2 Allowed Active Filter Line Cable with Typical Cable Manufacturer Data
How to Install
VLT Active Filter AAF 00x
MG.90.V2.22 - VLT
®
is a registered Danfoss trademark
4-15
4
4
