IG-183-EN version 06; 31/03/2020
24
Installation
General instructions
cgm
.3 system: medium voltage SF
6
gas-insulated
cubicles up to 38 kV according to IEEE and CSA standards
4.3. Recomended cable trenchs
Recomended mínimum dimensions according to the
dimensions of the trench used during the test according
to the IEC 62271-200 standard. Depending on the radius of
curvature of the cables used these dimensions may vary.
4.3.1. Cubicles with gas tank internal arc up to 20 kA - 0,5 s
Tests conducted with a test current of 21 kA. Consider
in each case the cable used in each installation.
Feeder, busbar raise and cable raise functions
The mínimum dimensions of the cable trench depend of
the mínimum radius of curvature of the cables used:
D1
Frontal or rear cables incoming or outgoing
D2
Lateral cables incoming or outgoing
Figure 4.3.
Dimensions [mm] of the cable trench for
cgm
.3-l
,
cgm
.3-rb
and
cgm
.3-rc
Necessary cable trench for feeder, busbar raise and cable raise functions
Cable data
Minimum depth
Cable
insulation
Cable type
Cable section
[mm
2
]
Cable
diameter
[mm]
Indicative
radius of
curvature*
[mm]
D1
[mm]
D2
[mm]
Dry insulation
One-core
18/30 kV
< 150
41
555
200
500
185
43
590
200
550
240
45.2
640
300
47.5
685
300
660
400
50.5
745
Three-core
18/30 kV
< 150
92.7
805
650
650
* Check with the cable used manufacturer’s data.
Table 4.2.
Necessary cable trench for feeder, busbar raise and cable raise functions
