AS/NZS 62086.2:2002

1 - AS/NZS 62086.2:2002 Electrical apparatus for explosive gas atmospheres-Electrical resistance trace heating-Application guide
4 - PREFACE
5 - CONTENTS
7 - 1 Scope
7 - 2 Normative references
8 - 3 Definitions
8 - 4 Application considerations
8 - 4.1 General
9 - 4.2 Corrosive areas
9 - 4.3 Installation considerations
10 - 4.4 Process temperature accuracy
10 - 4.4.1 Type I
10 - 4.4.2 Type II
10 - 4.4.3 Type III
10 - 5 Thermal insulation
10 - 5.1 General
11 - 5.2 Selection of insulating material
11 - 5.3 Selection of weather barrier (cladding)
13 - 5.4 Selection of economical thickness
13 - 5.5 Double insulation
15 - 6 System design
15 - 6.1 Introduction
15 - 6.2 Purpose of, and major requirement for, trace heating
15 - 6.3 Heat loss calculations
16 - 6.4 Heat-up considerations
18 - 6.5 Heat-loss design safety factor
18 - 6.6 Selection of trace heater
19 - 6.7 Maximum temperature determination
19 - 6.7.1 Maximum workpiece temperature - Stabilized design
19 - 6.7.2 Sheath temperature - Metallic applications
20 - 6.7.3 Sheath temperature - Non-metallic pipe applications
21 - 6.8 Design information
21 - 6.8.1 Design information documentation
22 - 6.8.2 Isometric or heater configuration line lists and load charts
22 - 6.9 Power system
23 - 6.10 Start-up at low ambient temperatures
23 - 6.11 Long cable runs
23 - 6.12 Flow pattern analysis
25 - 6.13 Dead-leg control technique
25 - 6.14 Chimney effect
25 - 7 Control and monitoring equipment
25 - 7.1 General
25 - 7.2 Mechanical controllers
26 - 7.3 Electronic controllers
26 - 7.4 Application suitability
26 - 7.5 Location of controllers
26 - 7.6 Location of sensors
26 - 7.7 Alarm considerations
26 - 7.7.1 General
27 - 7.7.2 Trace-heating circuit alarm
27 - 7.7.3 Temperature alarms
27 - 7.7.4 Other alarms
27 - 7.7.5 Integrated control
28 - 8 Recommendations for installation, testing and maintenance
28 - 8.1 Introduction
28 - 8.2 Application
28 - 8.3 Preparatory work
28 - 8.3.1 General
28 - 8.3.2 Personnel
28 - 8.3.3 Receiving materials
28 - 8.3.4 Warehousing and handling
28 - 8.3.5 Pre-installation testing
29 - 8.3.6 Pre-installation checks
30 - 8.3.7 Scheduling of installation
30 - 8.3.8 Surface preparation
30 - 8.3.9 Component substitution
30 - 8.4 Installation of trace-heating systems
30 - 8.4.1 General
30 - 8.4.2 Bonding to earth
30 - 8.4.3 Terminations
31 - 8.4.4 Cold leads
31 - 8.4.5 Junction boxes
31 - 8.4.6 Cable entries and glands
31 - 8.4.7 Conductor terminations
31 - 8.4.8 Terminal end fittings
32 - 8.4.9 Jointing, splicing and modifications
32 - 8.5 Installation of trace heaters
32 - 8.5.1 General
32 - 8.5.2 Field (work site) tests
32 - 8.5.3 Thermal contact
32 - 8.5.4 Laying
33 - 8.5.5 Fixing and banding
33 - 8.5.6 Additional heat loss compensations
33 - 8.5.7 Protection from leaks
33 - 8.5.8 Damage protection
33 - 8.6 Installation of control and monitoring equipment
33 - 8.6.1 General
33 - 8.6.2 Sensor considerations
34 - 8.6.3 Sensor installation
34 - 8.6.4 Protection against damage
34 - 8.6.5 Exit of sensor from thermal insulation
34 - 8.6.6 Controller housing
34 - 8.6.7 Process temperature controllers
34 - 8.6.8 Other equipment
34 - 8.7 Installation of thermal insulation system
34 - 8.7.1 General
34 - 8.7.2 Preparatory work
35 - 8.7.3 Installation of the thermal insulation materials
35 - 8.7.4 Cladding
35 - 8.8 Commissioning
35 - 8.8.1 Pre-commissioning test
36 - 8.8.2 Trace-heating commissioning
36 - 8.9 Maintenance
36 - 8.9.1 General
36 - 8.9.2 Fault location
36 - 8.9.3 Fault rectification
36 - 8.10 Repairs
36 - 8.10.1 General
37 - 8.10.2 Practicability of repair to electric trace heaters
37 - 8.10.3 Repair techniques for electrical trace heaters
38 - 8.10.4 Earthing
38 - 8.10.5 Testing
42 - Annex ZZ - Variations to IEC 62086-2:2001 for application in Australia and New Zealand
42 - ZZ1 Introduction
42 - ZZ2 Technical variations

Provides guidance for the application of electrical resistance heating systems in areas where explosive gas atmospheres may be present. It provides guidance for the design, installation and maintenance of trace heating equipment and associated control and monitoring equipment. This part supplements the requirements specified in AS/NZS 62086.1. This Standard is a modified version of IEC 62086-2:2001.

This part of IEC 62086 provides guidance for the application of electrical resistance trace-heating systems in areas where explosive gas atmospheres may be present.This Standard shall be read in conjunction with AS/NZS 2381.1, which describes the fundamental considerations which affect the selection, installation and maintenance requirements of all electrical equipment used in explosive atmospheres.It provides recommendations for the design, installation and maintenance of trace-heating equipment and associated control and monitoring equipment.This part supplements the requirements specified in IEC 62086-1.

First published as AS/NZS 62086.2:2002.