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1、BRITISH STANDARD BS 5373:1977 Specification for Electrical safety requirements for room aerials UDC 621.396.67:614.825 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:56:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5373:1977 This British Standard, having been prepared under the directi
2、on of the Electronic Equipment Standards Committee, was published under the authority of the Executive Board on 30 June 1977 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference EEL/25/2 Draft for comment 75/23298 DC ISBN 0 580 09861 3 Cooperating organiz
3、ations The Electronic Equipment Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government department and scientific and industrial organizations: British Broadcasting Corporation British Electrical and Allied Manufactur
4、ers Association British Radio Equipment Manufacturers Association* Cable Television Association of Great Britain Department of Prices and Consumer Protection* Electrical, Electronic, Telecommunication and Plumbing Union Electricity Supply Industry in England and Wales* Electronic Components Board* E
5、lectronic Engineering Association* Engineering Equipment Users Association Institution of Electronic and Radio Engineers Post Office Radio and Electronic Component Manufacturers Association* Scientific Instrument Manufacturers Association The organizations marked with an asterisk in the above list,
6、together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Association of Public Address Engineers British Electrotechnical Approvals Board for Household Equipment Consumer Standards Advisory Committee Consumers Association Depart
7、ment of Energy Electrical Association for Women Electrical Research Association Institution of Electrical Engineers Radio, Electrical and Television Retailers Association Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:56:53
8、 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5373:1977 BSI 10-1999i Contents Page Cooperating organizationsInside front cover Forewordii 1Scope1 2References1 3Definitions1 4General requirements1 5Marking and instructions1 6Constructional requirements1 7Insulation requirements2 8Mechanical strength
9、2 Figure 1 Test hammer3 Figure 2 Arrangement for scratch test4 Publications referred to6 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:56:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5373:1977 ii BSI 10-1999 Foreword This British Standard has been prepared under the authority of the
10、Electronic Equipment Standards Committee and details the safety requirements and tests for room, set-top and similar indoor aerials. This standard is intended to provide for supplementary insulation in the aerial to reinforce the primary insulation of the receiver. It is considered that this insulat
11、ion, which is additional to that specified in BS 415 for the aerial socket of the receiver, is necessary to ensure adequate safety for an item such as a room aerial that is easily accessible and subject to frequent handling. Certification. It is strongly recommended that in view of the nature of thi
12、s specification manufacturers and purchasers should make use of the certification facilities described on the inside back cover of this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct ap
13、plication. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 6, an inside back cover and a back cover. This standard has been updated (see copyright d
14、ate) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:56:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5373:1977 BSI 10-19991 1 Scope This British Standard specifies electri
15、cal safety requirements both for separate room, set-top and similar indoor aerials for radio and television receivers and for aerials built-in as an integral part of a receiver, if the latter are removable by hand and have a coaxial cable fitted with a coaxial plug complying with the requirements of
16、 BS 3041. Aerials with mains operated amplifiers should also comply with the requirements of BS 415. This standard is concerned with electrical safety only and not with the performance or other properties of the aerial. 2 References The titles of the standards publications referred to in this standa
17、rd are listed on page 6. 3 Definitions For the purposes of this British Standard the following definitions apply. accessible part any part of the aerial that can be touched by: a) the jointed test finger II specified in BS 3042 when applied without appreciable force in every possible position; or b)
18、 the jointed test finger II specified in BS 3042 applied after the rigid test finger III specified in BS 3042 has been applied with a force of 50 N, directed inwards for 10 s to any aperture preventing the entry of the jointed test finger. the test fingers shall be applied before and after the remov
19、al of all parts that are removable by hand removal by hand an operation that does not require the use of a tool, coin or any other object 4 General requirements 4.1 The aerial shall be so designed and manufactured as to present no danger in use, particularly as regards personal protection against el
20、ectric shock. 4.2 Aerials supplied in a disassembled form shall meet the requirements of this standard when assembled in the most unfavourable manner, with movable parts put in the most unfavourable position. 4.3 Additionally, where the standard is used for the purposes of granting nationally recogn
21、ized certification marks, designs or constructions to which the tests specified do not fully apply, but that give an equivalent degree of safety and durability of safety, may be regarded as complying with this standard, subject to the findings of a special investigation by the authority granting the
22、 certification mark and pending the issue of an amendment or extension to this standard. 5 Marking and instructions 5.1 The aerial shall be marked with: a) the number of this British Standard, i.e. BS 5373; b) makers name or trademark, or name of responsible vendor; c) makers model or type reference
23、. Compliance shall be checked by inspection. 5.2 The marking shall be easily discernible on the aerial. It shall be indelible and legible. Compliance shall be checked by inspection and by the following test. The marking shall not be removed when rubbed lightly with a piece of cloth soaked with petro
24、leum spirit without additives and also with a piece of cloth soaked in water. 5.3 Aerials supplied in a disassembled form shall be supplied with adequate assembly instructions. 6 Constructional requirements 6.1 The aerial shall be so constructed that there is no possibility of an electric shock from
25、 accessible parts when plugged into a receiver with defective aerial terminal isolation. If protection is obtained by coating the surface of otherwise accessible metal parts with insulation, this insulation shall have a minimum thickness of 0.4 mm, and the dielectric strength test specified in 7.3 s
26、hall still be met after the three tests given in 6.1.1 to 6.1.3 are applied in that order. The tests may be made on a separate specimen of the material. 6.1.1 Ageing test. The coated part shall be subjected to the conditions specified in method Ba of BS 2011-2B:1966 at a temperature of 70 2 C, for a
27、 period of 7 days. After this treatment, the part shall be allowed to cool to room temperature; inspection shall show that the layer has not loosened or shrunk away from the base material. 6.1.2 Impact test. The part shall then be conditioned for a period of 4 h at a temperature of 10 2 C. Licensed
28、Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:56:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5373:1977 2 BSI 10-1999 While still at this temperature, the layer shall be subjected to a blow applied to any point of the layer that is likely to be weak, by means of the test hammer shown in Figur
29、e 1. After this test the layer shall not be damaged; in particular, it shall show no cracks visible to the naked eye. 6.1.3 Scratch test. Finally, the part shall be subjected to a scratch test. The scratches shall be made by means of a hardened steel pin, the end of which has the form of a cone havi
30、ng a top angle of 40 with a tolerance of 1, its tip being rounded with a radius of 0.25 0.02 mm. Scratches shall be made by drawing the pin along the surface at a speed of about 20 mm/s, as shown in Figure 2. The pin is so loaded that the force exerted along its axis is 10 0.5 N. The scratches are,
31、where practicable, at least 5 mm apart and at least 5 mm from the edge of the specimen. After the scratch test the layer shall neither have loosened nor be pierced and shall withstand a dielectric strength test as specified in 7.3, the test voltage being applied between the base material and the met
32、al foil in contact with the layer. 7 Insulation requirements 7.1 General. The aerial shall incorporate adequate insulation between all accessible parts and the terminal contacts of the interconnecting plug. The interconnecting plug shall be of the insulated body type but shall not be regarded as an
33、accessible part for the purposes of the test specified in 7.3. The safety of the aerial shall not be impaired by any humid conditions that may occur in normal use. Compliance shall be checked by means of the humidity treatment given in 7.2, followed immediately by the tests of 7.3. 7.2 Humidity trea
34、tment. Electrical components, covers and other parts that can be removed by hand shall be removed and subjected, if necessary, to the humidity treatment together with the main part. The humidity treatment shall be carried out in a humidity chamber containing air with a relative humidity maintained b
35、etween 91 % and 95 %. The temperature t of the air, at all places where the aerial can be located, shall be maintained at 30 + 0, 2 C. Before being placed in a chamber the aerial shall be brought to a temperature between t and t + 4 C. The aerial shall be kept in the chamber for 48 2 h. NOTEIn most
36、cases, the aerial may be brought to the specified temperature by keeping it at this temperature for at least 4 h before the humidity treatment is applied. Some methods of achieving the specified relative humidity are described in BS 3718 and BS 3898. The air in the chamber shall be stirred and the c
37、hamber shall be so designed that mist or condensed water does not precipitate on the aerial. After the humidity treatment the aerial shall show no damage within the meaning of this standard. 7.3 Insulation test and dielectric strength test. Immediately after the humidity treatment given in 7.2 has b
38、een applied the insulation between all accessible parts and the terminal contacts of the interconnecting plug shall be tested for insulation resistance with 500 V d.c. and for dielectric strength with an a.c. test voltage of 2 000 V r.m.s. applied for 1 min. The a.c. voltage shall be increased gradu
39、ally from zero at a rate of 75 V/s until the required test value is reached and shall be held at that value for 1 min. Where the accessible parts are non-conductive the insulation resistance and dielectric strength tests shall be made to a metal foil wrapped closely around the surface of the aerial.
40、 The measurement of the insulation resistance and the test for dielectric strength shall be made in the humidity cabinet or in the room in which the aerial was brought to the prescribed temperature, after the reassembly of those parts that may have been removed. The aerial shall be deemed to comply
41、with the requirements of this standard if the insulation resistance is not less than 2 M7 and no flashover or breakdown occurs during the dielectric strength test. NOTEMetal accessible parts should be connected together during the insulation and dielectric strength tests. 8 Mechanical strength 8.1 T
42、he aerial shall have adequate mechanical strength and be so constructed as to withstand such handling as may be expected in normal use. Compliance shall he checked by means of tests given in 8.1.1 to 8.1.4. 8.1.1 Drop test. Allow the aerial to fall ten times from a height of 2 m onto a wooden floor.
43、 8.1.2 Vibration test. Subject the aerial to a vibration endurance conditioning by sweeping, as specified in procedure B4 of BS 2011-2Fc:1966. The aerial shall be fastened in its normal position of use to the vibration generator by means of straps. The direction of vibration shall be vertical and th
44、e severity shall be as follows. Duration: 30 min Displacement amplitude: 0.35 mm Sweep frequency range: 10 Hz to 55 Hz to 10 Hz Sweep rate: approximately 1 octave/min Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:56:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5373:1977 BSI 10-19993
45、8.1.3 Impact test. Hold the aerial firmly against a rigid support and subject it to three blows from a spring operated impact hammer as shown in Figure 1, applied to every point of the exterior that protects metal parts and is likely to be weak, by pressing the hammer nose perpendicularly to the sur
46、face. 8.1.4 Interconnecting cable test. Apply test Ual (tensile) and test Ub (bending) of BS 2011-2.1U:19771) to the interconnecting cable. The applied force shall be 40 N (4.1 kgf). 8.2 After the tests given in 8.1.1 to 8.1.4 have been applied, the aerial shall withstand the insulation and dielectr
47、ic strength tests given in 7.3, and there shall be no possibility of an electric shock from accessible parts when it is plugged into a receiver with defective aerial terminal isolation. 1) To be published. The test hammer consists of three main parts: the body, the striking element and the spring lo
48、aded release nose. The body comprises the housing, the striking element guide, the release mechanism and all parts rigidly fixed thereto. The mass of this assembly is 1.25 kg. The striking element comprises the hammer head, the hammer shaft and the cocking knob. The mass of this assembly is 0.25 kg.
49、 The hammer head has a hemispherical face of radius 10 mm and is of polyamide having a Rockwell hardness of R 100; it is fixed to the hammer shaft in such a way that the distance from its tip to the plane of the front of the nose, when the striking element is on the point of release, is 20 mm. The nose has a mass of 60 g and the nose spring is such that it exerts a force of 20 N when the release jaws are on the point of releasing the striking element. The hammer spring shall be so adjusted that the product of the compression, in millimetres, and t