Page 17 - Electrical Installation in Hazardous Area

xiv Contents

18.2 Legislation and enforcement 504
18.3 Basic installation requirements 505
18.3.1 Pre-installation checks 506
18.3.2 General installation recommendations 506
18.3.3 Post-installation checks 507
18.3.4 Earthing and bonding 507
18.3.5 Application of earthing 509
18.3.6 Application of bonding 510
18.3.7 Electrical isolation 514
18.3.8 Conduit and cable installation 516
18.4 Additional requirements or relaxations for particular
protection concepts 520
18.4.1 Hameproof electrical apparatus ‘d’ 520
18.4.2 Increased safety apparatus ’e’ 528
18.4.3 Type ’N apparatus 533
18.4.4 Other types of protection 533
18.4.5 Particular problems 533
18.5 Heating tapes 534
19 Installation of pressurized apparatus and other uses of the
pressurization technique 538
19.1 Standards for pressurization 539
19.2 Certification/approval 539
19.3 Basic installation approach 540
19.4 Pressurization arrangements 541
19.4.1 Pressurization with leakage compensation
using air 544
19.4.2 Pressurization with leakage compensation
using inert gas 546
19.4.3 Pressurization with continuous dilution
using air 548
19.4.4 Pressurization with continuous dilution using
inert gas 550
19.5 Safety devices and procedures 551
19.5.1 Manufacturer provision of control devices and
systems 551
19.5.2 Manufacturer provision of control devices only 552
19.5.3 Manufacturer provision of control information
only 553
19.6 Purge gas and operation of control system (gas,
vapour and mist risks) 554
19.6.1 Gases used 554
19.6.2 Basic operation of pressurization system 554
19.7 Multiple enclosures 556
19.8 Typical pressurization control system 557