BS 559:1991 download free.Specification for Electric signs and high-voltage luminous-discharge – tube installations.
1 Scope
BS 559 specifies requirements for the construction of electrically illuminated signs operating at high or low voltage and of high-voltage luminous-discharge-tube installations up to and including a nominal voltage of 5 kV to earth, whether used for publicity, decorative or general lighting purposes. either for external or internal use. Such signs or high-voltage luminous-discharge-tube installations may be either fixed or portable.
BS 559 does not apply to the following items which operate at low voltage:
a) luminaires (covered by BS 4533); b) exit signs (covered by BS 2560).
BS 559 does not cover luminance of signs.
NOTE 1 Guidance on the luminance of signs is given in Report No. 5 “The Brightness of Illuminated Advertisements” issued by the Institution of Lighting Engineers.
NOTE 2 The titles of the publications referred to in this standard are listed on the inside back cover.
2 Definitions
NOTE Where the terms “voltage” and “current” are used, they imply the r.m.s. values unless otherwise stated.
For the purposes of this British Standard, the following definitions apply.
2.1
electric sign
a word, letter, model, emblem, border, outline, box, device, representation, announcement or direction, fixed or free standing, including the framework and backing, and the means of attachment to the building or supporting structure and the means of illumination forming an integral part thereof
2.2
luminous-discharge tube
any tube, or other vessel or device, which is constructed of translucent material, hermetically sealed, and designed for the emission of light arising from the passage of an electric current through a gas or vapour contained within it. The tube may be with or without a fluorescent coating
2.3
low voltage
a voltage normally exceeding 50 V a.c. or 120 V d.c. whether between conductors or to earth, but not exceeding 1 000 V a.c. or 1 500 V d.c. between conductors, or 600 V a.c, or 900 V d.c. between conductors and earth
8.3 Glass panels shall be supported by means of continuous mouldings, clips or troughs. Clips shall have a thickness not less than the value given in Table 6.
Clips and fixings for moulding shall be spaced at intervals not exceeding 230 mm along all glass edges. Clips nearest the corner of a glass panel shall be positioned not more than 75 mm from the corner. Direct contact between glass and metal shall be prevented by the use of spacing material.
8.4 Where glass panels consist of two or more plates of glass in close contact with each other, provision shall be made to prevent the entry between them of dust and moisture, in accordance with classification 1P54 of BS 5490.
9 Flat panels of plastics materials
9.1 Flat panels of acrylic or other plastics materials shall have a thickness not less than the value given in Table 7.
9.2 Individual panels of an installation shall have their edges supported and, if necessary, the whole panel supported by anti-deflection props, in order that the deflection at any point does not exceed 5 times the thickness of that panel under the following test conditions:
a) a uniformly distributed pressure of 1.5 kPa over the outside area of the installation;
b) a uniformly distributed pressure of 0.75 kPa over the inside area of the installation.
9.3 Allowance shall be made for the difference in linear expansion between the plastics panel and the supporting material of the sign.
NOTE Such means should ensure that the panel and its seating comply with 3.6 under all temperature conditions liable to occur under normal use. Account should be taken of the effect of solar radiation.
9.4 Where plastics panels consist of two or more sheets of plastic in close contact with each other, provision shall be made to prevent the entry between them of dust and moisture, in accordance with classification 1P54 of BS 5490.
19.2 Invertors and convertors shall be installed in accordance with the recommendations of the manufacturer. The length of cable connecting the high-voltage terminal of an invertor or convertor to a discharge tube shall be not greater than that specified by the manufacturer. A metal-sheathed cable shall not be used for this connection.
19.3 Invertors and convertors with a rated input greater than 50 W shall have one point on the output circuit connected to earth and there shall be no direct connection between any output terminal and either mains supply terminal. Invertors and convertors with a rated input greater than 50 W and with more than one pair of output terminals shall have one point in each output circuit connected to earth.
19.4 Invertors and convertors shall have an open circuit voltage to earth not greater than 5 kV, this voltage being either the r.m.s. value or 0.5 times the peak value, whichever is the greater.
NOTE 1 The manufacturers of the invertors or convertors normally speciIv the output voltage in their literature. NOTE 2 Invertors can provide an output of alternating current. not necessarily of sinusoidal form, but exceeding 1 000 V and at a frequency in excess of 10 kHz. The parts of such installations operating at high frequency are outside the scope of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers, but the installation, protection and switchgear of the mains supply to such installations are within the scope of the Regulations.
NOTE 3 Requirements for creepage distances and clearance for invertors and convertors are given in 3.4 and 26.4. NOTE 4 Requirements for cables which are connected to invertors or convertors are given in 24.7 and 24.9.
20 Auxiliaries for discharge lamps
20.1 Auxiliaries for luminous-discharge-tube installations operating at high voltage, such as inductors, capacitors and resistors shall be either totally enclosed in an earthed metal enclosure (which may form part of the sign or luminaire), or placed in a ventilated enclosure constructed in accordance with classification IP:34 of BS 5490 and manufactured from a material with ignitability characteristic P as specified in BS 476-5.
20.2 Safety signs complying with 14.4 shall be placed on enclosures which are accessible to unauthorized persons.
20.3 Covers on enclosures shall be securely fastened and the removal of the covers shall require the use of a tool. Any fixings used to attach covers shall be captive.
20.4 Auxiliaries shall be installed in accordance with the manufacturer’s instructions except that if there is conflict with the requirements of 20.1. the latter shall apply.
a) An interference suppressor should be connected in the mains supply leads and fitted as close as possible to the flasher or dimmer unit. This suppressor should consist of 2 000 pH inductors connected in series with both line and neutral conductors, together with three I pF capacitors connected in a delta configuration (line to earth, neutral to earth and line to neutral) between the inductors and the flasher or dimmer unit. The capacitors should have a construction that is substantially non-inductive.
b) The flasher or dimmer unit should be screened by an earthed metal enclosure.
C) The mains supply leads from the suppressor to the flasher or dimmer unit and from the flasher or dimmer unit to the sign or luminous-discharge-tube installation should be installed within earthed metal conduit or trunking.
29.2 Components fitted to ensure compliance with 29.1 shall be rated for the voltages to which they will be subjected.