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1、BRITISH STANDARD AEROSPACE SERIES OBSOLESCENT NOVEMBER 1998 BS G 224:1978 Revision of BS G 194:1965 and BS G 200:1967 (see foreword) Incorporating Amendment No. 1 Specification for Lever-operated manual switches for aircraft UDC 629.7.064.5:621.316.542.1 Licensed Copy: London South Bank University,
2、London South Bank University, Sat Dec 09 02:24:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS G 224:1978 This British Standard, having been prepared under the direction of the Aerospace Standards Committee, was published under the authority of the Executive Board on 30 June 1978 BSI 04-2000 The fo
3、llowing BSI references relate to the work on this standard: Committee reference ACE/43 Draft for comment 76/77633 DC ISBN 0 580 10025 1 Foreword This British Standard specifies requirements for future designs and manufacture of lever-operated manual switches; it combines and revises the requirements
4、 specified in BS G 194 and BS G 200. Those two standards will not be withdrawn, however, until switches manufactured to those standards are no longer used. The standard specifies performance requirements, defines preferred dimensions and fixing holes. Switches are classified according to the environ
5、mental conditions for which they are suitable. The tests, which are grouped as type tests, production acceptance tests and quality assurance tests, include a test of the force required to operate the switch and recommends suitable tests for verifying the serviceability of the switches after storage
6、or use. Account has been taken in this standard of the requirements in International Standards ISO 493 and ISO 1466. References to BS 2G 100 have been revised to the relevant parts of BS 3G 100 and certain other amendments effected in the interests of clarity. A British Standard does not purport to
7、include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. 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, p
8、ages i and ii, pages 1 to 15 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No.Date of issueComments 2711June 1978Indicat
9、ed by a sideline in the margin Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:24:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS G 224:1978 BSI 04-2000i Contents Page ForewordInside front cover 1Scope1 2References1 3General requirements1 3.1Description and
10、design requirements1 3.2Rating2 3.3Declarations2 3.4Marking2 4Particular requirements2 4.1Operation2 4.2Construction2 4.3Dimensions3 4.4Environmental requirements3 5Tests3 5.1Nature and order of tests3 5.2Standard test conditions3 5.3Particular test requirements4 6Type approval tests4 6.1General nat
11、ure of tests4 6.2Order of tests4 6.3Supervision by Approving Authority4 6.4Preliminary requirements4 6.5Sample identification4 6.6Test records4 6.7Action in event of failure4 6.8Experimental flight approval (EFA)4 6.9Mechanical strength tests5 6.10Operating force test6 6.11Mechanical endurance tests
12、6 6.12Voltage drop test6 6.13High voltage and insulation resistance tests6 6.14Temperature rise test6 6.15Electrical endurance tests6 6.16Overload tests7 6.17Short-circuit tests7 6.18Vibration tests7 6.19Acceleration tests7 6.20Temperature-pressure-humidity tests7 6.21Tropical exposure test8 6.22Mou
13、ld growth test8 6.23Lever bush sealing test8 6.24Sealing test8 6.25Explosion-proofness test8 6.26Salt mist (corrosion) test8 6.27Driving sand test9 6.28Impact shock9 6.29Fluid contamination tests9 6.30Examination and report9 Licensed Copy: London South Bank University, London South Bank University,
14、Sat Dec 09 02:24:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS G 224:1978 ii BSI 04-2000 Page 7Production acceptance tests9 7.1General nature of tests9 7.2Workmanship and finish9 7.3Marking9 7.4Correct contact sequence9 7.5Operating test9 7.6Operating force test9 7.7Voltage drop test9 7.8High vol
15、tage and insulation resistance tests9 7.9Consequence of failing production tests9 8Quality assurance tests10 8.1General nature of tests10 8.2Method of test10 8.3Selection of samples10 8.4Action in event of failures10 9Serviceability tests10 9.1General10 9.2Method of test10 Appendix A Driving sand te
16、st13 Appendix B Impact shock13 Appendix C Fluid contamination tests13 Appendix D Serviceability tests14 Figure 1 Envelope dimensions for lever-operated manual switches14 Figure 2 Fixing holes and details of locating washer15 Figure 3 Typical test circuit for short-circuit test15 Figure 4 Sequence of
17、 groups of tests for quality assurance15 Table 1 Environmental tests: proof conditions5 Table 2 Altitude and cycles of operation6 Table 3 Type test schedule11 Table 4 Quality assurance test schedule12 Table 5 Sand composition13 Table 6 Pulse acceleration and duration (shock)13 Table 7 Test fluids14
18、Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:24:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS G 224:1978 BSI 04-20001 1 Scope This British Standard specifies the requirements for two basic sizes (A and B) of single-hole fixing, lever-operated manual swi
19、tches for use in nominal 28 V d.c. and 115/200 V three-phase, 400 Hz a.c. systems in aircraft. Two classes of environmentally sealed switches in each basic size are specified as follows. 2 References The titles of the standards publications referred to in this standard are listed below. BS 410, Test
20、 sieves. BS 2011, Basic environmental testing procedures Part 2 Ea. Test Ea. Shock. BS 4760, Numbering of weeks. BS 6001, Sampling procedures and tables for inspection by attributes. BS 2G 100, General requirements for electrical equipment and indicating instruments for aircraft Part 2:1962 Environm
21、ental and operating conditions Paragraph 213. Leakage tests for hermetically sealed equipment. BS 3G 100, General requirements for equipment for use in aircraft. Part 0: Introduction; Part 1: Identification and declarations; Part 2: All equipment; Section 1: Construction; Section 3: Environmental co
22、nditions; Subsection 3.1 Vibration; Subsection 3.2 Temperature-pressure requirements; Subsection 3.3 Mould growth; Subsection 3.5 Explosion-proofness; Subsection 3.6 Acceleration requirements; Subsection 3.7 Tropical exposure; Subsection 3.8 Salt mist; Subsection 3.12 Fluid contamination; Part 3: Ch
23、aracteristics of aircraft electrical systems; Part 4: Electrical equipment; Section 1 Construction and general; Subsection 1.1 Electrical insulation tests. BS G 176, Cartridge fuses for aircraft. BS 3G 178, Crimped joints for aircraft electrical cables and wires. BS G 216, Hand operated, thermally c
24、ompensated, miniature single- and triple-pole circuit breakers. ISO 493, Aircraft Dimensions for single-hole mounting (Class 1 and Class 2) lever-operated manual switches1). ISO 1466, Lever-operated manual switches for aircraft Performance requirements1). 3 General requirements 3.1 Description and d
25、esign requirements 3.1.1 The switches shall comply with the requirements of this British Standard. 3.1.2 The switches shall be suitable for one of the following temperature and altitude classifications. Class 1. Switches that are sealed and suitable for use at altitudes up to 21 300 m and for temper
26、atures within the range 54 C to + 85 C; they shall not suffer damage nor deterioration when subjected to temperatures within the range 54 C to 62 C (non-operating), and shall be suitable for occasional operation within the temperature range + 85 C to + 120 C. Class 2. Switches that are only sealed a
27、t the lever bush and suitable for use at altitudes up to 6 100 m at temperatures within the range 40 C to + 85 C and for occasional use at 21 300 m. 3.1.3 The switches shall be suitable for mounting through the panel from the rear and shall operate satisfactorily when mounted in any attitude. 3.1.4
28、The switches may be the two- or three-position type, with one or more poles: they may be self-retaining and/or spring return with or without lever locking. 3.1.5 The method of operation of the switch shall be by means of a single lever, moving in a plane at right angles to the mounting panel. The re
29、lationship of the lever positions to the keyway shall be as shown in Figure 1, and the relationship of the terminal numbers to the lever positions 1, 2 and 3 shall be as stated in the individual specification. 3.1.6 The switch terminals shall be identified by number in the sequence shown in the indi
30、vidual specification. Class 1. Switches suitable for high altitude and wide temperature conditions. Class 2. Switches suitable for lower altitudes and narrower temperature conditions than class 1 switches. 1) Referred to in foreword only. Licensed Copy: London South Bank University, London South Ban
31、k University, Sat Dec 09 02:24:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS G 224:1978 2 BSI 04-2000 3.2 Rating 3.2.1 Voltage. The switches shall be suitable for operating in nominal 28 V d.c. and 115/200 V three-phase, 400 Hz a.c. systems having the characteristics specified in BS 3G 100-3. In
32、addition, the switch shall be suitable for use at voltages down to 4 V d.c. or a.c. 3.2.2 Current. The switches shall be suitable for all of the following normal current ratings. Inductive loads shall be as follows: 28 V d.c.: 40 mH 115/200 V a.c.: 0.75 power factor lagging 3.3 Declarations. In addi
33、tion to the declarations required by BS 3G 100-1, the manufacturer shall declare: a) the classification; b) the limits of the forces necessary to operate the switch to any position; c) the system of batching used for quality test sampling; d) the switch operation relative to the lever position, the
34、keyway and the terminal numbering. 3.4 Marking 3.4.1 In addition to the terminal numbering, the following minimum information shall be clearly and indelibly marked on each switch: a) BS G 224 and classification, indicating compliance with the requirements of this standard; b) the manufacturers name
35、or identification; c) the manufacturers type number; d) resistive current rating; e) voltage rating (d.c. and a.c.); f) date code (see 3.4.2). 3.4.2 Each switch shall be marked with a code indicating the date of manufacture. The first number in the code shall be the last two digits in the number of
36、the year. The second number shall consist of two digits indicating the calendar week of the year; when the calendar week consists of a single digit, it shall be preceded by a zero. Week 01 is defined as the first week containing four days or more of the new year. In accordance with BS 4760 the first
37、 day of the week is taken as Monday and week 01 is the week containing the first Thursday in January. Reading from left to right or from top to bottom, the code shall designate the year and the week in that order. 4 Particular requirements 4.1 Operation 4.1.1 The switch lever action shall be positiv
38、e and it shall not be possible during normal usage for the lever to stay in any position other than a fully-operated position. The operation of the switch shall not be affected adversely by the speed of movement of the lever. 4.1.2 It shall not be possible to rotate the lever about its longitudinal
39、axis. 4.1.3 The angular movement of the lever shall be 20 2 from the central position. 4.1.4 There shall be a minimum of 8 movement and a maximum of 16 movement of the lever before switching occurs. In multipole switches the contact opening mechanism shall be mechanically linked so that the remainin
40、g poles operate within 2 movement following the initial contact change. 4.1.5 The lever shall be capable of withstanding without damage or distortion a force of 90 N applied steadily in the directions specified in 6.9.2. 4.2 Construction 4.2.1 The lever, including any metal inserts, shall be insulat
41、ed from all live parts. 4.2.2 The force required to operate the switch shall be not less than 4.5 N and not more than 45 N. For each operation of a particular type of switch, the maximum force shall not exceed the minimum force by more than 100 %. The manufacturer shall declare the maximum and minim
42、um values of the force for each operation appropriate to each type of switch. 4.2.3 Where locking of the lever is provided, it shall be positive and automatic, and the lock shall be released by raising the lever against a spring force of 4.5 N to 22.5 N. 4.2.4 The exposed portion of the switches sha
43、ll have a non-glaring finish. LoadSize ASize B a) Resistive15 A5 A b) Inductive10 A3 A c) Lamp (28 V d.c.)7.5 A2.5 A d) Lamp (200 V a.c.)2.5 A1.5 A e) Low power (4 V)0.01 A0.01 A Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:24:44 GMT+00:00 2006, Uncontroll
44、ed Copy, (c) BSI BS G 224:1978 BSI 04-20003 4.2.5 The switches shall be sealed at the point of entry of the lever to prevent the ingress of liquids or foreign matter. In addition, the bodies of class 1 switches shall be sealed to the standard required by the test in 6.24. 4.2.6 Terminations shall be
45、 as follows. Size A switches. Screw threads of size M4 0.7 capable of accepting two crimped tag type terminations, of approved design, or integrated terminal junctions suitable for size 16 cables. Size B switches. Screw threads of size M3 0.5 capable of accepting two crimped tag type terminations, o
46、f approved design, or integrated terminal junctions suitable for size 20 cables. 4.2.7 The terminal arrangement shall be such that wiring access is still provided when the switches are mounted in rows having minimum spacing, with the side faces that are parallel to the lever movement being adjacent
47、to each other. The switches shall be suitable for close mounting and shall not constitute an electrical hazard if the side faces of adjacent switches touch one another. Means shall be provided to avoid accidental contact or short-circuiting between adjacent terminals of the switch. 4.2.8 The switche
48、s shall be mounted by means of a M12 1 threaded bush with a locating keyway in the plane of movement of the lever. Two hexagon mounting nuts, one locating washer, and one locking washer of approved type shall be provided with each switch. 4.2.9 The switches shall be so constructed that each switch i
49、s suitable for performing at least 50 000 cycles at maximum rated current and voltage. 4.2.10 The switch contacts, including common internal connections, should be self-wiping on all switched contact positions. 4.2.11 The lever mechanism should incorporate a positive contact opening action to assist in breaking a tack weld. In addition, the lever position should indicate whether the contact is open or closed. 4.2.12 Only the appropriate contacts shall operate when the lever is suddenly
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