1) For cables having copper conductors of nominal cross-sectional area 1 mm2, the order shall be specified if the conductors are plain or tinned.APPENDIX A
GUIDE TO USE
A1. Scope
This Appendix is valid for the application of cables according to HD 604 Part 4 Section B.
A2. Object
The object of this Appendix is to provide an example of recommendations for the 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 application
The cables considered are mainly intended for use indoors, laid on cable trays, in nuclear power generating plants.
All these cables may be used inside containment of nuclear power stations when they comply with additional tests and requirements not specified here, specially to demonstrate that they are capable of performing their specified functions under accident and postaccident conditions.
A3.2 Environmental conditions
When these cables are used in nuclear power stations, outside containment, the environmental influences to be taken into account for cables are, under:
storage/ installation conditions
normal conditions
A3.2.1 Storage/ installation conditions
These conditions apply to all cables in storage or in the course of installation, located outdoors and in unprotected premises.A4. Requirements concerning the sizing of power cables **’
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 short-circuits between cable ends are not taken into account in sizing cables fit 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°C is adopted for those 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 air-conditioning 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 types ('''
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 are normally overhead; 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 types 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 > 0.15 m, when the cable trays are parallel and stacked,
.d2 > 0.10 m, when the cable trays cross in separate planes,
.d3 > 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.SECTION C: CABLES WITHOUT METALLIC COVERING,
HAVING CIRCULAR COPPER CONDUCTORS
Replace pages 4-C-3. 4-C-11 and 4-C-12 by the following:'BLANK PAGE'
In case of printing, the print height shall be 15% of the specified overall diameter as a minimum. The number shall be printed in a colour which contrasts with the oversheath colour.
Compliance shall be checked by visual examination and measurement.
2.3 Additional test requirements
Sampling for sample tests
Electrical resistance of the conductor.
The electrical resistance of the conductor shall be checked on 20% of the finished lengths or on 5 lengths, whichever is the greater. The measurement shall be made on all the conductors of each length of cables selected for the test.
Insulation resistance on cable length.
The insulation resistance shall be measured on 10% of the finished lengths or on 3 lengths, whichever is greater. The measurement shall be made on each core up to a maximum of two of each length of cable selected for the test.
Bending test.
The bending test shall be performed on samples taken from the finished lengths on the following basis:
|
|
Cable length |
Number of |
|
Above |
Up to and including |
samples |
|
(km) |
(km) |
|
|
0 |
2 |
1 |
|
2 |
5 |
1 |
|
5 |
10 |
2 |
|
10 |
30 |
3 |
|
30 |
— |
4 |
Notes: 1. In calculating the above mentioned lengths it is permitted to assemble cables with different cross-sections.
2. If the total length in the contract does not exceed 2km, it is permitted to omit the test provided the manufacturer can demonstrate to have successfully performed the test on at least one similar cable sample on the occasion of previous contracts.
Construction, marking and dimensions
The construction, marking and dimensional checks shall be performed on 5% of the finished lengths, rounded upwards.
Checks relevant to cores shall be limited to three cores of each length of cable selected for the test.
Physical tests, insulation resistance at high temperature, water absorption. Physical tests, insulation resistance at high temperature and water absorption test shall be performed on samples taken from the finished lengths on the following basis:
|
Cable length |
Number of |
|
|
Above |
Up to and including |
samples |
|
(km) |
(km) |
|
|
0 |
2 |
1 |
|
2 |
10 |
1 |
|
10 |
|
2 |
Notes: 1. In calculating the above mentioned lengths it is permitted to assemble cables with different cross-sections.
2. If the total length in the contract does not exceed 2km, the test may be omitted provided the manufacturer can demonstrate to have successfully performed the same tests on at least one similar cable sample on the occasion of previous contracts.
The purchaser may wholly or partly omit the tests even in case of delivered lengths greater than 2km, when providing reliable results of test carried out on the occasion of previous contracts.
The test pieces required for the physical tests on insulation shall be taken at random from different cores.
Insulation resistance at high temperature and water absorption shall be made on each core up to a maximum of three of each length of cable selected for the test.
Repetition of the tests.
If any cable length (or cable sample) should fail in any of the tests a), b) and d), the same test or tests in which the original sample failed shall be carried out on all cable lengths in the contract and the defective ones shall be rejected.
If a cable sample should fail in any of bending test, insulation resistance at high temperature, water absorption test, the same test or tests in which the original sample failed shall be carried out on two further samples. Should either of them fail, the batch of which these samples are representative shall be regarded as failing to comply.
If a cable sample should fail in any of the physical tests, the same test or tests shall be carried out on another sample. In this case the sample shall have a sufficient length to allow the test pieces to be taken from positions at least 1 m apart.
Should the new sample fail, the batch of which this sample is representative shall be regarded as failing to comply.
The number of cores to be checked shall be as stated in items a) to e).
Measurements of cable dimensions
When the overall dimension of the cable is checked in accordance with sub-clause 2.1.3.1 of HD 605, the mean overall dimension shall comply with the values specified in Tables 4 to 7.
When ovality of the cable is checked in accordance with sub-clause 2.1.3.2 of HD 605, the difference between the maximum and minimum value of the diameter shall not exceed 15% of the overall diameters specified in Tables 4 to 7.
Bend test on complete cable
The bend test shall be carried out at ambient temperature in accordance with sub-clause 2.4.1.1 of HD 605, immediately after conditioning in a straight arrangement for at least 1h at (0 ± 3)°C.
The mandrel diameter shall be 16 (D + d) ± 5%, D and d being respectively, the measured overall and conductor diameters.
After the bend test, the U-bent cable shall be immersed in water at ambient temperature, leaving above water a length of sample adequate for the test.Table 3 - Schedule of tests
|
1 |
2 |
3 |
4 |
5 |
|
Ref. |
Test |
Category |
Test method |
Requirement given |
|
No |
|
of test |
described in |
in clause (*) |
|
1 1.1 |
Electrical tests Conductor resistance |
S |
HD 383 |
3.3.1 |
|
1.2 |
Voltage test on complete cable |
R |
HD 605 3.2.1 |
2.3.5 |
|
1.3 |
Insulation resistance tests: a) Core |
S |
HD 605 3.3.1 |
2.3.6 |
|
|
b) Complete cable |
S |
HD 605 3.3.3 |
2.3.6 |
|
2 2.1 |
Constructional and dimensional characteristics Conductor: a) material & construction |
S |
Visual examination |
3.3.1 |
|
|
b) tinning of wires |
S |
HD 605 2.5.3 |
2.3.4 |
|
2.2 |
Insulation: a) Application |
S |
Visual examination |
Part 1, 5.2.2, 3.3.2 |
|
|
b) Thickness |
S |
HD 605 2.1.1 |
& Part 1, 5.2.3 |
|
2.3 |
Core identification |
S |
Visual examination |
2.1 & Part 1,4 |
|
2.4 |
Oversheath a) Application |
S |
& measurement Visual examination |
3.3.4 & Part 1, |
|
|
b) Thickness |
S |
HD 605 2.1.2 |
5.7.2 3.3.4 & Part 1, |
|
2.5 |
Cable markings |
S |
Visual examination |
5.7.3 2.2 & Part 1, 3 |
|
2.6 |
Cable dimensions: a) Overall dimension |
S |
& measurement HD 605 2.1.3.1 |
2.3.2 |
|
|
b) Ovality |
s |
HD 605 2.1.3.2 |
2.3.2 |
|
3 3.1 |
Mechanical & physical tests Insulation: a) Mechanical properties in the |
s |
Table 1 |
3.3.2 |
|
|
state as delivered. b) Mechanical properties after |
s |
Table 1 |
3.3.2 |
|
|
ageing in air oven c} Mechanical properties after |
s |
Table 1 |
3.3.2 |
|
|
ageing in air bomb d) Ozone resistance |
s |
Table 1 |
3.3.2 |
|
|
e) Hot set test |
s |
Table 1 |
3.3.2 |
|
|
f) Water absorption - gravimetric |
s |
Table 1 |
3.3.2 |
|
|
(standard method) - electric |
s |
Table 1 |
3.3.2 |
|
|
(only on agreement between manufacturer and purchaser) |
|
|
|
(') Clause numbers refer to this section unless stated otherwise.
Table 3 (concluded)
|
1 |
2 |
3 |
4 |
5 |
|
Ref. |
Test |
Category |
Test method |
Requirement given |
|
No |
|
of test |
described in |
in clause (') |
|
3.2 |
Oversheath: |
|
|
|
|
|
a) Mechanical properties in the |
S |
Table 2 |
3.3.4 |
|
|
state as delivered |
|
|
|
|
|
b) Mechanical properties after |
S |
Table 2 |
3.3.4 |
|
|
ageing in the air oven c) Heat shock test |
S |
Table 2 |
3.3.4 |
|
|
d) Pressure shock test at high temp. |
S |
Table 2 |
3.3.4 |
|
|
el Bending test at low temp |
S |
Table 2 |
3.3.4 |
|
|
f) Elongation test at low temp |
S |
Table 2 |
3.3.4 |
|
|
gl Impact test at low temp. |
S |
Table 2 |
3.3.4 |
|
4 |
Bend test on complete cable (only for class 2 conductors) |
S |
HD 605 2.4.1.1 |
2.3.3 |
|
6 |
Test related to fire conditions on complete cable |
|
|
|
|
|
Flame propagation on bunched cables in the state as delivered |
T |
HD 605 4.1.3 |
2.3.7 |
