BS 7535:1992
Withdrawn
A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.
Hardcopy , PDF
08-01-2007
English
08-15-1992
Committees responsible
Foreword
Guide
Section 1. General
1.1 Scope
1.2 Definitions
1.3 Classification of hazardous areas
1.4 Properties of combustible dusts
1.5 Other hazards
Section 2. Principles for selection of apparatus and
systems
2.1 General
2.1.1 Selection according to apparatus construction
2.1.2 Selection according to surface temperature
2.1.3 Selection for use within the dust containment
2.2 Selection of apparatus complying with BS 5501 :
Part 2 (oil immersion 'o')
2.3 Selection of apparatus complying with BS 5501 :
Part 3 (pressurized apparatus 'p')
2.4 Selection of apparatus complying with BS 5501 :
Part 4 (powder filling 'q')
2.5 Selection of apparatus complying with BS 5501 :
Part 5 (flameproof enclosure 'd')
2.6 Selection of apparatus complying with BS 5501 :
Part 6 (increased safety 'e')
2.7 Selection of apparatus and systems in accordance
with BS 5501 Part 7 and 9 respectively
(intrinsically safe apparatus and systems 'i')
2.8 Selection of apparatus complying with BS 5501 :
Part 8 (encapsulation 'm')
2.9 Selection of apparatus complying with BS 6941
(with type of protection N)
Section 3. Installation of apparatus and systems
3.1 General
3.2 Installation of apparatus complying with
BS 5501 : Part 2 (oil immersion 'o')
3.3 Installation of apparatus complying with
BS 5501 : Part 3 (pressurized apparatus 'p')
3.4 Installation of apparatus complying with
BS 5501 : Part 4 (powder filling 'q')
3.5 Installation of apparatus complying with
BS 5501 : Part 5 (flameproof enclosure 'd')
3.6 Installation of apparatus complying with
BS 5501 : Part 6 (increased safety 'e')
3.7 Installation of apparatus and systems complying
with BS 5501 : Parts 7 and 9 respectively
(intrinsically safe apparatus and systems 'i')
3.8 Installation of apparatus complying with
BS 5501 : Part 8 (encapsulation 'm')
3.9 Installation of apparatus complying with BS 6941
(with type of protection 'N')
Section 4. Inspection, testing and maintenance of
apparatus and installations
4.1 General
4.2 Inspection, testing and maintenance of apparatus
complying with BS 5501 : Part 2 (oil immersion
'o')
4.3 Inspection, testing and maintenance of apparatus
complying with BS 5501 : Part 3 (pressurized
apparatus 'p')
4.4 Inspection, testing and maintenance of apparatus
complying with BS 5501 : Part 4 (powder filling
'q')
4.5 Inspection, testing and maintenance of apparatus
complying with BS 5501 : Part 5 (flameproof
enclosure 'd')
4.6 Inspection, testing and maintenance of apparatus
complying with BS 5501 : Part 6 (increased safety
'e')
4.7 Inspection, testing and maintenance of apparatus
and systems complying with BS 5501 : Parts 7 and
9 respectively (intrinsically safe apparatus
and systems 'i')
4.8 Inspection, testing and maintenance of apparatus
complying with BS 5501 : Part 8 (encapsulation
'm')
4.9 Inspection, testing and maintenance of apparatus
complying with BS 6941 (with type of protection
N)
Tables
1 Ip rating requirements and impact strength of
apparatus complying with BS 5501 and BS 6941
2 Minimum action on pressure failure
3 Minimum conductor sizes
4 Minimum clearances
5 Characteristics to be met and failures to be
taken into consideration for individual cable
types
6 Inspection schedule for all apparatus
7 Additional inspection schedule for apparatus
with additional protection
8 Class of insulating material and limiting
temperature
Figures
1 Identification of zones on drawings
2 Minimum tE time for motors in relation to IA/IN
3 Self-contained apparatus (F.2): paging system
4 Simple apparatus (F.3.4): thermocouple with
direct deflection indicator
5 Certified associated apparatus
6 Certified apparatus (F.3.2) with compatible
parameters
7 Other combinations of certified apparatus for
solenoid valve: barrier
8 Certified systems for microphone and loudspeaker
system
9 Typical procedural stages for intrinsically safe
installations
10 Conventional limit switch installation
11 Conventional level switch installation
12 Limit switches in common multicore possibly
subject to mechanical damage (type A cable)
13 Limit switches connected via a multicore
adequately supported and protected (type B cable)
14 Limit switch and float switch in individually
screened circuits bonded at different points
(type A or B cable)
15 Different circuits within an overall screen
bonded at one point (type B cable)
16 Typical installation of a screened and armoured
cable
Appendices
A Procedure for area classification
B Properties of combustible dusts
C Light metal construction and the associated
frictional sparking risks
D Selection of increased safety 'e' cage motors and
associated protection devices
E Illustrations of typical intrinsically safe
installations
F Certification of intrinsically safe electrical
apparatus and systems
G Examples of the more common combinations of
'earthed' circuits and screens
H Test for restricted-breathing
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