UL 268A:4ED 2008-12-11

Foreword
Introduction
1 Scope
2 General
3 Glossary
4 Installation and operating instructions
Construction
5 Enclosure
6 Remote accessories
7 Air flow monitoring
8 Protection against corrosion
9 Field-wiring connections
10 Internal wiring
11 Bonding for grounding
Components
12 General
13 Bushings
14 Electrical insulating material
15 Lampholders and lamps
16 Photocell illuminating lamps
17 Motors
18 Protective devices
19 Printed wiring boards
20 Switches
21 Transformers and coils
22 Dropping resistors
Spacings
23 General
24 Servicing and maintenance protection
Performance
25 General
26 Normal operation test
27 Electrical supervision test
28 Circuit measurement test
29 Air leakage test
30 Overvoltage and undervoltage test
31 Temperature test
32 Vibration test
33 Components replacement test
34 Jarring
35 Cover replacement test
36 Fire tests
37 Stability tests
38 Variable ambient temperature test
39 Humidity test
40 Corrosion test
41 Transient test
42 Static discharge test
43 Overload test
44 Endurance test
45 Abnormal operation test
46 Locked rotor test
47 Dielectric voltage-withstand test
48 Polarity reversal test
49 Tests of polymeric materials
50 Tests of elastomeric materials
51 Strain relief test
52 Radioactive material measurement test
53 Sensitivity tests of smoke sensing chamber(s)
Marking
54 General
55 Installation wiring diagram
56 Technical bulletin
57 Packaging marking
Supplement SA - Instructions for determining a
  reliability prediction of electronic components and
  microelectric circuits
SA1 Methods of determining failure rate
Supplement SB - Criteria for acceptance of
  microelectronic devices
SB1 General
SB2 Part I - Quality assurance screening program
SB3 Part II - Determination of failure rate number
     supplemented by burn-in test
Appendices
A Standards for components
B1 Analysis of radioactive elements

This revisions of ANSI/UL 268A dated August 18, 2020 includes Wiring, Grounding, and Related Requirements and Instructions; 3.11, Section 4, Table 5.2, 9.1.2, 9.2.1, 9.2.4, 9.3.1 – 9.3.5, 9.4.1, 9.5.2, Section 9.8, 10.1.1 – 10.1.6, 10.3.1 – 10.3.3, 10.5.1, 11.1 – 11.4, 11.6, 11.10, Section 24.3, 25.3.1(i), 36.5.1.1, 51.1, Section 51.3, 55.3(e)

1.1 These requirements cover air duct smoke detectors intended for indoor use within or protruding into a duct, or mounted in a housing with sampling tubes extending into or traversing a duct.