Страница 81: ДСТУ HD 604 S1:2012. Кабелі електроживлення на напругу 0,6/1 кВ і 1,9/3,3 кВ зі спеціальними протипожежними характеристиками для застосування на електростанціях (62577)

APPENDIX A

CURRENT RATING INFORMATION

к Basic assumptions

The miikrwm permlsslbb conductor temperatures In continuous operation ага as follows:

• EPAnnsuiated power cables in around + 70*C

• EPHnnsulatad power cables in ak + 70°C

• XLPE-insulated power cables in ргскжмі +65 °С

• XLPE^nsulated power cables in ar + 70°C

ki around installations the basic assumptions are:

• temperature of ground + 15*C

• depth of laying 0,7m

• thermal resistivity of soil 0.7 К m/W

In air installations the ambient is ♦ 25®C

Table A1
(aJ AhminhjfTi conductors

Bask permissible current ratings of two or more core 1kV power cables regardless of the insulation material. <See basic assumptions above J Maximum conductor temperature + 7O*C. Current values in amperes.

Table Al (concluded)

(bl Соооаг conductor»

The methods of installation have boon classified for cables not exceeding 1 kV and insulated conductors as follows:

Method A of installation: Cable has been instated so that the heat transfer coefficient between the cable surface and the outer surface of the wall or the material cowering the cable is К ■ 11 to SO W/®C m The method A of installation is considered to be:

• inlaid insulations generaly

• installation in lowered ceilings, installation troughs, gutters, mouldings etc

• installations that dearly do not belong to the method В of installation,

Method В of installation: Cable has been installed on the surface so that the heat transfer coefficient between the cable surface and the outer surface of the wall or the material covering the cable is К > 50°С m*. The method В of installation is considered to be among others:

• installation on surface (also In tubas) with its short passages

• cables on racks with its short passages

• inlaid insulation in stone constructions {concrete, tiles, etc ] - installation in shafts or cable ducts.

Table A2

Continuous permissible current ratings for three single-core power cablet with aluminium conductor in three phase use In air ini tai let bn Conductor temperature maximum + 70^ftC. Current values in amperes.

Table A3

Continuous permissible Current ratbge for three singie*core power cables with copper conductor In three phase им in air Installation. Conductor temperature maximum + 70*C. Current values in amperes.

Flat Installation: Cables paraMl, distance between cables equal to one cable diameter

Trefoil installation: Cables in trefoil touching each other.

2.

M¥£Th<FI7

laciou

When the instillation conditions differ from the basic conditions given in Sub-dsuse L the correction factors given in the following tables shall bo used.

2-1 Correction factors in ground metallations

Table A4

Correction lectors tor groups of cables laid directly bi ground

The values apply to mutticore cables and to groups of three single-core cables (in trefoil or flat formation) without or wHh spacing between the cables or the cable groups and with the cables or the cable groups horizontally placed.

Table A5

Correction lectors for different installation depths in ground

Table Аб
Correction factors for different thermal resistivities cl sol

Examples of thermal resistivities of soil: - dry sand (moisture content 0%) 3.0 К m/W - eemi dry and moist gravel 1,0 К m/W

* dry gravel end dev 1,5 К m/W * moist day and sand (moisture

’ semrdry gravel and sand (moisture content 25% 0.7 К m/W

content 10%) 1*2 К m/W

Table A7

Correction factors for different ground temperatures

For paraKei ducts with one multi-core cable or a group of three skigH-core cables in each and with the cables equally loaded, the correction factors in table A8 are used. If correction factors in Table AB are used, then the factors In Table A4 are not used.

Table AS

Correction factors for cables In unified plastic tubes

2.2 Correction factor* ineir hstalatlon

Table A9

Correction factors for different ambient air temperatures

Table A10

Correction Factors for Groups of muhicore cables laid in air

This applies only when rhe cable temperature does not affect the ambient ar temperature