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The folowing classes of cables:

(i) single core cables having akjmkikxn conductors and aluminium tape armour, (й) 2, 3 and 4 core cables having copper or aluminium conductors and steel tape armour, (mQ 2 up to 48 cor* cables having copper conductors without metallic armour, (rv) 2 up to 48 core cables having copper conductors and steel tape armour,

are mainly intended for use in general css*.

Th* classes (ій) and tiv) may be used inside containment of nuclear power stations when they comply with additional tests requirements not specified her*,

These cables may be laid indoors on cable trays, outdoors ki air or underground, buried directly in tranches or in ducts set in concrete or in troughs or kt galleries. The control cables without metallic armour (class (IS) above* shall be only used inside electrical cabinet.

The following class of cables:

(vl 2, 4, 7, 8 up to 37 core cables having copper conductors and metallic anu tnducticn screen,

is mainly intended for use in areas where high-level high-frequency disturbances ere likely, for instance in the vicinity of HV equipment, in power plants and also in substations.

These cables may be laid indoors on cable trays, outdoors in «г or underground buried in tranches with protective device, in ducts set in concrete, in troughs or in gaMeries,

A3.2 Environmental condrtions^

When these cables are used in conventional or nuclear power stations, outside containment th* environmental influences to be taken into account are, under

- storage/insta nation cofidrtwns, normal conditions.

Excerpt from “Design and Construction Rules for Electrical Equipment of Nuclear Islands (RCC-El* published by 'Association fran^aise pour les regies de conception at de construction des m*t4n*ls des chaudidres electro-nudSaires, 9AFCENI", chapter D 2200.

АЗ,2,1 $toraaeMat»ilation conditions

These conditions apply to all cables in storage or in the course of installation, located outdoors and in unprotected premises.

A3.2.2 Normal enviforimefltal,conditions (outride containment!

These conditions apply to installed cables, whether in service or idle, the power station being erther in operation or shut down_f and are flrven in the table below.

Note: о • 10 m t¹

(1| Vibrations are constant amplitude up to the transition frequency of 67 Hz and constant acceleration above that frequency.In space conditioned areas, when ventilation is lost, the temperature may exceptionally гіи to a maximum value of 40^QC, tor a maximum one-time duration ot 24 hours, once a year.

A4. Requirements concerning the arnrrn of power cables¹"¹

Cables are sized on the fol lowing basis:

• The cable ia able to carry permissible steady-state current. This current, which is given in the cable specitication, depends on such factors as ambient temperature, cable construction and routing. This leads to a temperature rise In steady 'State operation.

• The cable is capable of withstanding a faulty current which may occur, without deterioration. It sustains a conductor temperature nee appreciably higher than that occurring under continuous load. The temperature rise depends essentially on the type of cable insulation used. Effects of short-circuits between cable ends are not taken into account in sizing cables (it is assumed that the cable Is simply replaced].

• The cable does not produce an excessive voltage drop between the power source and the load, under steady-state conditions or during motor startup. The cable cross-section is selected so that the voltags at the motor terminals Is 0 8 Un when bus voltage is at the lower limit of the normal range.

Note: In practice and depending on the intended service, each cable may ba sized on the basis of only one of the above criteria.

Ambient temperature Із Uken into account as follows:

• as a general rule, an ambient temperature of 30 *C ts adopted for those cables supplying equipment which can be de energised In the event of a general loss of air-condi tuning which, sooner or later, leads to plant shutdown;

• a higher temperature may be adopted for cables supplying equipment which is necessary In the event of a general loss of ventilation and, in particular, those cables which are necessary for air-conditioning equipment;

• however, overheating of cables is acceptable for short periods since this has only a minor effect on serves fcfe.

A5. Sanaraiion rules betwwn cables of different etectncal type»¹"'

The purpose of the separation between cables of different electrical types is to protect the venous electrical circuits from electromagnetic interference.

The rules described be tow concern all cables.

The folowing electrical types can be distinguished;

• medium voltage power,

• low voltape power,

• utility (telephone, intercom, pubhc address system, lighting, etc).

• control, - instrument.

Th* separation enter ion taken into account is the voltage level and the nature of the signals

The routings may be either overhead or buried: the following method* may be used.

A5J Overhead routings

In the same raceway, the cable tray* яге assigned tn the following way:

cables of different electrical tray* are routed on different cable tray* or risers,

- on horizontal or diagonal raceway*, the cable trays assigned to power cable* are located <n the upper pan and the order of assignment of the cable trays compile* with figure 1,

the control and low voltage power cables may run on the sama tray in secondary raceway* I see sutr clause A7.2),

instrument cables run through enclosed troughs when a power саЫ* IMV or LVJ passe* lea* than 1m away,

instrument cables transmitting signal* output by nuclear instrumentation system detectors, or signal* of comparable level pass through enclosed trough*. These instrument cables can also transmit the HV specific to the detector power supply.

The minimum distance* to be respected between the cable tray* carrying cables of different electrical type* are Isa* figure 21:

di i 0J5m₍ when the cable (ray* ar* paraNal and stacked.

d2 b 0.10 m, when the cable tray* cross in separate planes,

d3 2 0.10 m, when the cable tray* are parallel on the same horizontal plane.

These distances presuppose that the instrument cable* pass through enclosed trough*.

A5.2 Buried routings

For buried routings, a minimurn distance of 1 m is observed between power cables and instrument cable*, and 0.20 m between power cables and control cables.

If th* instrument cables cannot be separated by at least 1 m, a minimum distance of OJO m tt acceptable, provided these cables pa** through a metal sheath.

A6. Recommendations_for storeo* antf yansqgn

A6.1 Delvenr

The distance between rhe outer cable layer of a filed-up cable delivery drum and the head of th* flange shall be sufficiently high to avoid damages of the cable.

AS 2 Cable end seafona

Each cable end shall be fitted with suitable end dev>ces to prevent ingress of humidity during storage, delivery and laying.A6.3 Transport

For the transport of filled up cable reals only suitable carri era shell be used-

Cable drums with flang* diameters exceedinQ 1 m have to be transported with the drum-axis in a horizontal position. The drum have to be protected against movement. Loading and unloading shall be made by suitable devices to avoid damage to the cables and the cable-drums.

Riled up cable-drums shaR be rolled only on short distances over plain solid ground in the (fraction indicated. The cable ends have 10 be tightened.

A7. Recommendations for cable laving and Installation

A7.1 Pidbnfl in and bending radius

Pulling in of cables is made either manually, or rnecharxcaly.

In the case of mechanically puling in:

pulling force *S limited to 5 daNAnm* for copper conductors and to 3 daN/mm* for aluminium conductors;

for power cables, pulling is directly exerted on cores,

the pulbng forces shall be permanently checked during the pulling in procedure.

The cables are then pulled out of their supports and carefully arranged on them,, so as to avoid crosS'Spticing and overlapping which may hinder pood cable tray occupation.

Appropriate devices shall be provided along the cable run. and especially at angles, to avoid sheath tearing.

A cable leaving a horizontal cable tray, should as far as possible ba removed by the bottom or in the case of a cable trough, by the side-

During pulling in procedures, the bending radius shall not tall below the folowing values:

20 times the outer diameter for power cables,

16 times the outer diameter for measuring cables and control cables.

In a definitive situation, the bending radius shall never be leu than 10 times its outer diameter.

During pulling in, fire screens shaR be provisionally sealed by means of plastic bags fitted with mineral wool. Tha begs shall be rearranged after each passage.

The lowest allowed temperature of the cables during installation and mounting of accessories is: 10°С for PVC insulated and sheathed cables.

MV power

IV power

Utility

Control

Int<runent

1. 
   

‘

<11 2 0.15 я

POSITIONING OF CABLE TRAYS CORRESPONDING TO THE VARIOUS TYPES OF CABLE

dl I 0,10 •

2. - SEPARATION DISTANCE BETWEEN CABLE TRAYS

А7 2 Cables laid ос cable wavs

Cable trays are used for holding cables over the if entire rune.

Two types are used, depending on the rxenber of cables in the run:

main raceway* (width i 300 mm],

secondary raceways (width £ 200 mm|.

Main horizontal raceways are those which are effectively horizontal and those inclined at an angle of less than or equal to 45* with the horizontal. They consist of superimposed, parallel open or enclosed cable trays secured to brackets, themselves secured to posts anchored to the power station structures»

Main vertical raceways form an angle greater than 45 ^е with the horizontal They consist of risers featuring: either the same components as horizontal cable trays, or single or double ladders, depending on whether one or both sides are to allow for cable attachment when the raceway forms an angle of SO* with horizontal*

Secondary raceways are placed *n any position required for the cable run and may be integrated with main raceways. They consist of: enclosed trays, conduits or individual fittings enabling attachment of cables by means of clips.

A7.2.1 Fixinn of cables - General rule

On horizontal cable trays:

• cables are laid without fixing when the iodination with respect to the horizontal is less than 20*,

cables are fixed with clips apprcramatery every 3 m when the iodination with respect to the horizontal Is between 20° and 45*.

In vertical risers, cables are secured approximately every metre by mean* of a dip.

The beginning of changes in direction are defined by supports (cross-pieces, brackets, etc») to which the cables are fixed. Moreover, the cables are secured tn elbows to ensure that they remain flat.

The clips used are made of dass-M2 plastic, the dassriication of materials being defined on the basis of their reaction to fire. In outdoor areas, the plastic shell be resistant to sunlight,

A7,2,2 Fixing of cables - Special cases

Dips are made of stainless steel in the following cases:

• in vertical risers more than & m high.

- or securing three-cable bundles of single coca cables to cable trays.In addition, in three-caMe bundles of single core cables, the three cables are held together over their entire run with stainless steel dips. The distance between consecutive dips is calculated so as to guarantee resistance to eUctrodynamic forces caused by short’ circuits The clipping together and fixation to the cable tray may be combined or independent.

AZ3 Cables la*d ю trenches

Cables are placed in the bottom of the trench at a depth of 0.80 m on a bed of sand approximately 5 cm thick. Sea sand shaU not be used.

The width of the trench depends on the number of cables to be laid in it bearing in mind the spacing detailed in sub-dause A5.2 and below.

• Cables are covered with a 10 cm layer of sand. During filling in with screened earth, plasticised netting is placed horizontal? 30 cm above the cables to indicate their proximity.

After tilling in and surface soil levelling, the cable path is indicated by standardized concrete markers embedded at ground level. These markers are placed at ell angles on the run and every 20 m in the straight sections.

• The space between power cables shall be as great as possible and never less than 20 cm (as measured between the outer generating fines of the cables).

Power cables are laid in a single layer.

Single core cables are grouped in threes in the form of a triangle and secured with clips.

A7.4 С*Ым l»id in ducts s*t in concrete

• Each duct we to contao oMy cables with the tame fewest characteristics; the space between adjacent ducts is 10 cm.

• For single core cables, each cable requires a separate duct, the three ducts forming a triangle.

• Ducts are made of plastic but each group of ducts contains one or more Staal ducts for measurement cables.

Only half of the duct capacity is used.

• For considerable lengths, pits placed at angles to the run and at intervals of approximately БО m in straight sections are provided for cable puffing in

Ducts entering buddings are plugged to a thickness of 10 cm after cable drawing, using a water- repelent and fire-resistant product approved by the client.

AZ5 Cables laid in troughs and oalferiefi

A7 5.1 Cables laid in troughs

Troughs are used in different ways depending on their capacity and the nature of cables running in them.

They are divided into the foltowing types:

• low-capacity troughs carrying several different types of cables; the ceWes are laid either on cable trays or directly on brackets 350 to 400 mm apart;

low-capacity troughs carrying a single type of cable; these cables are laid di reedy on the bottom of the troughs;

• high-capacity troughs in which a 500 mm wide passage is provided the whole length of the cable tray-

Trough routings are forbidden in rooms containing liquid fuel.

In outdoor areas, precast concrete troughs may be used- with one or more cavities pet type of cable.

А7.Б.2 Cables laid m oaJienes

Galleries are considered to be troughs with extremely high capacity. The cable trays with which they are fitted are the same as those specified for raceways described in sub­clause A .7.2.

Cables are positioned according to the same rules as for main raceways.append S

CURRENT RATINGS

The appropriate values of current-carrying capacities may be determined as described in IEC Publication 287 In either case account may be taken of the characteristics of the load and. for buried cables, the effective thermal resistance of the soil.

The basic operating conditions are as follows:

for cables in air

• 30°C air temperature

• continuous load

for buried cables

• 20°C ground temperature

a continuous load

homogeneous soil thermal resistrvky 1 K.m/WSECTION C CA9LES WITH CIRCULAR COPPER CONDUCTORS
WITH OR WITHOUT METALLIC COVERING

СОШЕИК

Paoe

1. Scope 3'C'2

2. Additional general requirements

2d identification of cores 3-C-2

2. 2 Cable marking 302

3. .3 Additional test requirements 303

3. Cables without metallic covering

3d Code designation 3-C-6

1. 2. Rated voltage Э-С-7

   3. Construction 307

   4. Tests 307

2. Cables wrtii metallic coveting

   2. Code designation 307

   3. Rated voltage УС-7

   4. Construction 308

   5. Tests 300

Tables: 1 - 10 309

Appendix: Guide to use 3022

RVFREftCES

References are made, in this Section C of Pan 3 of HD 604, to other Pans of this HD and to other Harmonisation Documents and International Standards as follows: