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How to Install
4.5 Electrical Installation
4.5.1 Power Connections
Cabling and fusing
NOTE
Cables General
4
4
All cabling must comply with national and local
regulations on cable cross-sections and ambient
temperature. UL applications require 75 °C copper
conductors. 75° and 90 °C copper conductors are thermally
acceptable for use in non UL applications.
The power cable connections are situated as shown below.
The mains connection is fitted to the mains switch if this is
included. Dimensioning of cable cross section must be
done in accordance with the filter current rating including
skin and proximity effects, derating and local legislation.
Mains must be connected to terminals 91, 92 and 93. Earth
is connected to the terminal to the right of terminal 93.
Terminal No.
91, 92, 93
94
The conductor is predominantly carrying currents of high
frequencies so the distribution of current is not evenly
dispersed throughout the cross section of the conductor.
This is due to two independent effects known as skin
effect and proximity effect. Both effects make derating
necessary and consequently the mains wire of the Active
Filters have to be rated at a higher current then the filter
rating itself.
Filter
190A
250A
310A
400A
Table 4.2 Allowed Active Filter Mains Cable with Typical Cable Manufacturer Data
22
VLT Active Filter AAF 00x
Function
Mains R/L1, S/L2, T/L3
Earth
Min CU wire
2
70mm
(2/0)
120mm
2
(4/0)
2
240 mm
(500MCM)
2
2*95mm
(2*3/0)
MG.90.V2.02 - VLT® is a registered Danfoss trademark
3 Phase
power
input
NOTE
If 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 is depending on frequency of conduct,
cable material and cable dimensions. The proximity effect
is depending on the number of conducts, diameters and
distance between the individual cables.
The optimized mains wire is:
•
Cupper wires
•
Single conducts
•
Busbars
The reason for that is that cupper has lower skin effect
factors then aluminium, busbars have bigger surface area
compared to cables reducing the skin effect factor and
proximity effects of single conducts is negligible.
The following cables specifications take both skin and
proximity effects into account:
Min ALU wire
2
95mm
(3/0)
150mm
2
(300MCM)
2
2*95mm
(2*3/0)
2
2*150mm
(2*300MCM)
91 (L1)
92 (L2)
93 (L3)
95 PE
Max wire
2
2*150mm
(2*300MCM)
4x240mm
2
(4x500MCM)
2
4x240mm
(4x500MCM)
2
4x240mm
(8x900MCM)
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