BS 6776:1990 download free.British Standard Specification for Edison screw lampholders.
BS 6776 applies to fampholders with Edison thread El4. E27 and E4D. designed for connection to the supply of lamps and semi-luminaircs’ only.
It also applies to switched-lampholders for use in ac. circuits only, where the working voltage does not cxcced 250 V r.rn.s.
BS 6776 also applies to lampholders with Edison thread ElO designed for connection to the supply of series-connected lamps with a rated voltage not exceeding 60V. to be used indoors or outdoors.
As far as it reasonably applies. BS 6776 aLso covers lumpholders other than lampholdcrs with Edison thread designed for Connection of series-connected lamps to the supply.
This type or lampholder is for example used in Christmas-tree lighting chains.
As far as it reasonably applies, the standard also covers lampholders which tire, wholly or partly. integral with a luminaire or intended to be built into appliances. Independent lampholders. cg. hack- plate lampholders. not specifically intended for building-in. are also tested its luminaires.
BS 6776 applies to lampholdcrs to bc uscd indoors or outdoors in residential us well us in industrial lighting installations. Ii also applics to candic lumpholdcrs. In locutions where special conditions prevail. us for street lighting. on board shipi. in vchiclcs and in hazardous locations. e.g. whcrc explosions arc liable to occur. speckil constructions may be required.
BS 6776 does not apply to ihrce.light lampholdcrs E26d.
BS 6776 is based on thc following diiia relative to lamps For gcncril lighting wrv.:
— clips E14 arc used for lumps with a current not exceeding 2A
— caps E27 aerc used for lumps with a current not exceeding 4A:
9.1 Lampholders ElO. E14 and E27 shall be so designed that the lamp caps are not accessible when they bccomc live during insertion.
l)eiaik rw checking compliance regarding protection against uccidcniail curnaci during in.erIion br lampholders Eli)
arc under idcrntion.
Lampholders E40 shall be so designed that the lamp cap is not accessible wlic:i fully inserted.
Candle lmnpholdcrs arc tested without decorative cover, unless this cover cannot be removed without making the lampholders obviously useless.
(Jonipliu,ice is checked ax follows:
– For lampholders EU), by tnean.v of corresponding lamps and the standard us, fiuiger. shown in Figure 18. For the purpose of the lexi, the lanipholder manufacturer shall proi’ide the lcniips for which the kunphsolckr is miended.
– br lainpholtIer £14. £27 and £40. by means of gauges according to the current edition of the Julio lying stun durci sheets of I E C Publication 61-3:
— 7(X)6-3l frr iwupiwiders £14;
— 7(NM-22A for lumpholckrs E27;
— 7KK-2d for lwnpholderx £40.
9.2 The external parts of enclosed and indcpcndent lampholders shall be so designed that live parts of the lainpholder ready for use and with a corrcsponding normal lamp inserted are not accessible.
Candle himpholders are tested without decorative cover, unless this cover cannot be removed without making the lampholder obviously useless.
(‘ui;i,iliuiice is checked by means of the standard lest finger. For the purpose of the test:
— l:,irlt&wd lam plwhkrs are moats ted as in nornwl use, for example on a ihreath’d support, or the like, if
12. 1 Lampholders shall be provided with a screw thread of Edison form for holdiiig the lamp.
For lampholders other than ElO. this thread shall be either of metal and shall be continuous over a length not less than that specified in the cuirent edition of standard sheet 7005-20 of JEC Publication 61-2. or comply with the following requircinenis:
Tb requninlcnI lot a minimum lcngth of rew ihreud For lampholders EI() b under consideration.
Deviation from the requirements for a metal thread is allowed provided the design and production tolerances are such that proper engagement with all gauges is ensured throughout the life of the holder delivered. On this subject. further information will be available in the appendix: Surveillance tests. tinder consideration.
lii addition, the terminal/contact assembly and the screw shell shall be so constructed and located as to prevent cinting or rotation which would impair the use of the lampholder.
Deviation from the requirement for a Continuous thread is allowed if this is necessary to provide a special technical advantage, such as the inclusion of a lamp retention device in a cut-away.
üiinplia,ice is checked by inspt’ctio?l and by a manual iesi with the relevant gauges, referred to in Clause 8. applied in nil positions ,s’hlch can be achieved with reasonable force, and the holder shall still urn ply with the gauges. especially the jeeler gauge of 0.08 mm x 5.0 mm.
IurIlI(rmr)re. it shall not he poxsibk to score the iieck of the bulb of a lamp made to normal standards Iuring e,sgagei,u’nI and dise.igageneiu.
l2.2 There shall he ample space for the supply wires in the dome of the lampholder. Parts of the lampholder with which insulated conductors may come into contact shall have no sharp edges or a shape likely to damage the insulation.
19.3 Contacts and all other current-carrying parts shall be so constructed as to prevent excessive temperature rise.
Compliance is checked by the following test which shall be made immediately after the lest of Sub. clause 19.2 on the lampholder in whose terminals conductors of the maximum cross-sectional area according to Sub-clause 10.1 are fitted.
The terminal screws are tightened with a torque equal to iwo-thirds of the torque specified in Sub-clause 16.1; the latnpholder is placed with the open end downwards and loaded for 1 h with 1.25 limes itS rated current. The temperature rise of terminals shall not exceed 45 K.
In case of lampholders intended for use in refrigerators and food freezers which are marked with the lamp wattage, 0.5 A shall be taken as Its rated current.
This temperature is determined with the aid of melting particles or by thermocouples. nor by means of thermometers.
For this test, a special lest cap shown in Figure 12, is used.
After the lest, it is verified thai, as required in Sub-clause 10.4. the conductors are nor damaged.
Peflcis of beeswax (diamctcr 3 mm. mclting temperature 65C) may be used a. mclting particics provided (hat the ambient temperawre equals 20’C.
Thcse requirements do not apply to lampholders ElO.
19.4 The resistance to heat is then tested in a healing cabinet at the temperature indicated in the table below.