Control cableTable 12 - Inner sheath and oversheath thickness of cables with metallic screen
|
Fictitious diameter over laid-up cores D, (mm) |
Inner sheath thickness mean value (mm) |
Oversheath thickness mean values (mm) |
|
D, £ 13 |
0.8 |
1.3 |
|
13 < D, £ 21 |
1.0 |
1.5 |
|
21 < D, < 29 |
1.2 |
1.7 |
|
29 < D, |
1.4 |
1.9 |
Table 13 - Thickness of armour tapes
|
Fictitious diameter DA under the armour |
Nominal thickness of the tapes |
|
(mm) |
(mm) |
|
Da< 30 |
0.2 |
|
30 < DA £ 70 |
0.5 |
|
70 < Da |
0.8 |
Table 14 - Oversheath thickness of power cables with metallic armour (see Table 15 for preferred designs)
|
Fictitious diameter Df over the insulation (single core) or over the assembly protection (multicore) (mm) |
Nominal thickness of the oversheath (mm) |
|
D, £ 16 |
1.8 |
|
16 < Df < 20 |
2.0 |
|
20 < Df £ 24 |
2.2 |
|
24 < D, £ 32 |
2.4 |
|
32 < D, £ 36 |
2.6 |
|
36 < D, < 40 |
2.8 |
|
40 < D, £ 44 |
3.0 |
|
44 < Dt £ 48 |
3.2 |
|
48 < D, £ 52 |
3.4 |
|
52 < Df £ 64 |
3.6 |
|
64 < Df |
3.8 |
Table 15 - General constructional requirements for preferred designs of Power cables with metallic armour
|
Number x nominal cross-sectional area of conductors (n x mm2) |
Thickness of insulation (mm) |
Thickness of inner sheath (mm) |
Thickness of armour tapes (mm) |
Thickness of oversheath (mm) |
|
1 x 240 |
2.2 |
1.5 |
0.2 |
2.2 |
|
1 x 400 |
2.6 |
1.6 |
0.2 |
2.4 |
|
2 x 2.5 |
0.8 |
1.2 |
0.2 |
1.8 |
|
2x6 |
1.0 |
1.2 |
0.2 |
1.8 |
|
2x16 |
1.0 |
1.3 |
0.2 |
1.8 |
|
2 x 35 |
1.2 |
1.4 |
0.2 |
2.0 |
|
2x 95 |
1.6 |
1.7 |
0.2 |
2.4 |
|
2 x 150 |
1.8 |
1.8 |
0.5 |
2.6 |
|
2 x 240 |
2.2 |
2.0 |
0.5 |
3.0 |
|
3 x 2.5 |
0.8 |
1.2 |
0.2 |
1.8 |
|
3x6 |
1.0 |
1.2 |
0.2 |
1.8 |
|
3x16 |
1.0 |
1.3 |
0.2 |
1.8 |
|
3 x 35 |
1.2 |
1.4 |
0.2 |
2.0 |
|
3 x 95 |
1.6 |
1.7 |
0.5 |
2.4 |
|
3 x 150 |
1.8 |
1.9 |
0.5 |
2.8 |
|
3 x 240 |
2.2 |
2.1 |
0.5 |
3.2 |
|
3 x 95 + 50 |
1.6 - 1.4 |
1.8 |
0.5 |
2.6 |
|
3 x 150 + 70 |
1.8 - 1.4 |
1.9 |
0.5 |
2.8 |
|
4 x 2.5 |
0.8 |
1.2 |
0.2 |
1.8 |
|
4x6 |
1.0 |
1.2 |
0.2 |
1.8 |
|
4x 16 |
1.0 |
1.3 |
0.2 |
1.8 |
|
4x 35 |
1.2 |
1.5 |
0.2 |
2.2 |
APPENDIX A
GUIDE TO USE
Al. SefiCS
This Appendix is valid for the application of cables according to HD 604 Part 3: "0.6/1 kV single core and multicore PVC insulated and sheathed cables” - Section B.
A2. Object
The object of this Appendix is to provide an example of recommendations for selection, storage, transport and installation of the cables specified under item A1, Scope. These recommendations are not exhaustive, others may be used.
A3. Recommendations for use
A3.1 Permissible applications
The cables considered are mainly intended for use in conventional power generating plants and in standard areas {outside containment) of nuclear power stations.
The following classes of cables:
single core cables having aluminium conductors and aluminium tape armour,
2, 3 and 4 core cables having copper or aluminium conductors and steel tape armour,
2 up to 48 core cables having copper conductors without metallic armour,
2 up to 48 core cables having copper conductors and steel tape armour,
are mainly intended for use in general case.
The classes (iii) and (iv) may be used inside containment of nuclear power stations when they comply with additional tests requirements not specified here.
These cables may be laid indoors on cable trays, outdoors in air or underground, buried directly in trenches or in ducts set in concrete or in troughs or in galleries. The control cables without metallic armour (class liii) above) shall be only used inside electrical cabinet.
The following class of cables:
2, 4, 7, 8 up to 37 core cables having copper conductors and metallic anti-induction screen,
mainly intended for use in areas where high-level high-frequency disturbances are 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 air or underground buried in trenches with protective device, in ducts set in concrete, in troughs or in galleries.
A3.2 Environmental conditions1*1
When these cables are used in conventional or nuclear power stations, outside containment, the environmental influences to be taken into account are, under:
storage/installation conditions,
normal conditions.
Excerpt from "Design and Construction Rules for Electrical Equipment of Nuclear Islands (RCC- Е)" published by "Association francaise pour les regies de conception et de construction des mat6riels des chaudiferes 6lectro-nuclfiaires, {AFCEN)", chapter D 2200 (1993).
A3.2.1 Storaoe/installation conditions
These conditions apply to all cables in storage or in the course of installation, located outdoors and in unprotected premises.
E
Range/remarks
-25°Cto + 40°C
Oto 100 %
Splashing
Ambient air temperature: extreme values
Relative humidity
Water
A3.2.2 Normal environmental conditions (outside containment)
These conditions apply to installed cables, whether in service or idle, the power station being either in operation or shut down, and are given in the table below.
|
Environmental influence |
Range/Remarks |
|
||
|
Outside areas |
Sheltered areas |
Heated and ventilated areas |
Heated and/or cooled areas |
|
|
- Ambient air temperature . extreme values |
- 25 °С to + 40 °С |
-10 °С to + 40 °С |
+ 5 °С to + 36 °С |
+ 10 °С to 30 “C |
|
. maximal daily average . annual average |
+ ЗО °С + 20 °С |
+ 30 °С + 20 °С |
+ 30 °С + 23 "C |
+ 26 °С + 23 °С |
|
- Relative humidity |
0 to 100% |
0 to 100% |
0 to 70% |
0 to 70 % |
|
- Water |
Splashing |
Splashing |
Nil |
Nil |
|
- Atmospheric pressure |
86 to 106 kPa |
86 to 106 kPa |
86 to 106 kPa |
86 to 106 kPa |
|
- Temperature rise above ambient (from thermal radiation and conduction) |
. 0 К in recirculated air . + 16 К in once- through or partially recirculated air |
. 0 К in recirculated air . + 1Б К in once- through or partially recirculated air . + ЗО К in high temperature areas |
. 0 К in recirculated air . + 6 К in unventilated or slightly ventilated areas |
. 0 К in recirculated air . + 6 К in slightly ventilated areas |
|
- Dust |
Substantial |
Substantial |
Negligible |
Nil |
|
- Salt |
Salt air |
Salt air |
Nil |
Nil |
|
- Support vibration (1); . frequency a) Equipment (general) . amplitude p-p . acceleration |
10 to 2 000 Hz 0 to 30 ijm 0.2 g |
10 to 2 000 Hz 0 to 30 jjm 0,2 g |
10 to 2 000 Hz 0 to 30 pm 0,2 g |
10 to 2 000 Hz 0 to 30 pm 0,2 g |
Note: g » 10 m.s.'2
(1) Vibrations are constant amplitude up to the transition frequency of 57 Hz and constant acceleration above that frequency.
In space-conditioned areas, when ventilation is lost, the temperature may exceptionally rise to a maximum value of 40°C, for a maximum one-time duration of 24 hours, once a year.
A4. Requirements concerning the sizing of power cables12*1
Cables are sized on the following basis:
. The cable is able to carry permissible steady-state current. This current, which is given in the cable specification, 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 rise appreciably higher than that occurring under continuous load. The temperature rise depends essentially on the type of cable insulation used. Effects of shortcircuits 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 voltage 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 be sized on the basis of only one of the above criteria.
Ambient temperature is taken into account as follows:
as a general rule, an ambient temperature of 30 °С is adopted forthose cables supplying equipment which can be de-energised in the event of a general loss of air-conditioning 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 airconditioning equipment;
however, overheating of cables is acceptable for short periods since this has only a minor effect on service life.
A5. Separation rules between cables of different electrical types1*'1
The purpose of the separation between cables of different electrical types is to protect the various electrical circuits from electromagnetic interference.
The rules described below concern all cables.
The following electrical types can be distinguished:
medium voltage power,
low voltage power,
utility (telephone, intercom, public address system, lighting, etc),
control,
instrument.
The separation criterion taken into account is the voltage level and the nature of the signals.
The routings may be either overhead or buried; the following methods may be used.
A5.1 Overhead routings
In the same raceway, the cable trays are assigned in the following way:
cables of different electrical trays are routed on different cable trays or risers,
on horizontal or diagonal raceways, the cable trays assigned to power cables are located in the upper part and the order of assignment of the cable trays complies with figure 1,
the control and low voltage power cables may run on the same tray in secondary raceways (see sub-clause A7.2),
instrument cables run through enclosed troughs when a power cable (MV or LV) passes less than 1 m away,
instrument cables transmitting signals output by nuclear instrumentation system detectors, or signals of comparable level, pass through enclosed troughs. These instrument cables can also transmit the HV specific to the detector power supply.
The minimum distances to be respected between the cable trays carrying cables of different electrical types are (see figure 2):
d1 a 0.15 m, when the cable trays are parallel and stacked,
d2 > 0,10 m, when the cable trays cross in separate planes,
d3 s 0.10 m, when the cable trays are parallel on the same horizontal plane.
These distances presuppose that the instrument cables pass through enclosed troughs.
A5.2 Buried routings
For buried routings, a minimum distance of 1 m is observed between power cables and instrument cables, and 0.20 m between power cables and control cables.
If the instrument cables cannot be separated by at least 1 m, a minimum distance of 0.10 m is acceptable, provided these cables pass through a metal sheath.
A6. Recommendations for storage and transport
A6.1 Delivery
The distance between the outer cable layer of a filled-up cable delivery drum and the head of the flange shall be sufficiently high to avoid damages of the cable.
A6.2 Cable end sealing
Each cable end shall be fitted with suitable end devices to prevent ingress of humidity during storage, delivery and laying.SECTION C: CABLES WITH CIRCULAR COPPER CONDUCTORS,
WITH OR WITHOUT METALLIC COVERING
Replace pages 3-C-3. 3-C-13 and 3-C-14 bv the following'.'BLANK PAGE'
External marking
The external surface of all cables shall be legibly marked as follows:
cables without metallic covering
N1VV-K. 1 x cross section or N1VV-K n x cross section or N1VV-R n x cross section
cables with metallic covering
N1VC7V-K n x cross section or
N1VC7V-R n x cross section
The legend shall be along one or more lines, and in the latter case the lines shall be approximately equally spaced around the circumference.
The gap between the end of one legend and the beginning of the next one shall not be greater than 0.5 m.
When embossing or indenting is used, the letters and figures shall consist of upright block characters. In the legend, the maximum size of the characters shall be 13 mm and the minimum size 15% of the specified overall diameter or 3mm, whichever is greater.
