ANSI UL 458 User manual

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UL 458
ISBN 1-55989-212-9
Power Converters/Inverters
and Power Converter/Inverter
Systems for Land Vehicles and
Marine Crafts

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Underwriters Laboratories Inc. (UL)
333 Pfingsten Road
Northbrook, IL 60062-2096
UL Standard for Safety for Power Converters/Inverters and Power Converter/Inverter Systems for Land
Vehicles and Marine Crafts, UL 458
Fourth Edition, Dated December 14, 1993
Revisions: This Standard contains revisions through and including October 15, 2004.
Summary of Topics
The revisions dated October 15, 2004 are being issued to incorporate requirements in
accordance with:
Responses to comments received on the Fourth Edition of UL 458, the Standard for
Power Converter/Inverter Systems for Land Vehicles and Marine Crafts, balloted for ANSI
approval in the E-mail dated April 21, 2003, and
Revisions proposed in Subject 458 bulletin dated July 9, 2004 based on the comments
received.
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dated July 9, 2004. The bulletin(s) is now obsolete and may be discarded.
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Copyright © 2004 Underwriters Laboratories Inc.
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This Standard consists of pages dated as shown in the following checklist:
Page Date
1-12B ........................................................................October 15, 2004
13.........................................................................December 14, 1993
14 ........................................................................September 11, 1998
15-16 ........................................................................October 15, 2004
17-19 ......................................................................December 14, 1993
20-24B.......................................................................October 15, 2004
25.........................................................................December 14, 1993
26-26B.......................................................................October 15, 2004
27-28 ......................................................................December 14, 1993
29-30B.......................................................................October 15, 2004
31.........................................................................December 14, 1993
32...........................................................................October 15, 2004
33-34 ......................................................................December 14, 1993
35-36A.......................................................................October 15, 2004
36B ..............................................................................July 8, 1996
37-42 ......................................................................December 14, 1993
43-44A.......................................................................October 15, 2004
44B.......................................................................September 11, 1998
45-46 ......................................................................December 14, 1993
47-48 ........................................................................October 15, 2004
49.........................................................................December 14, 1993
50-51 ........................................................................January 27, 1995
52-53 ......................................................................December 14, 1993
54...........................................................................October 15, 2004
55.........................................................................December 14, 1993
56...........................................................................January 27, 1995
57-58B.......................................................................October 15, 2004
59...........................................................................January 27, 1995
60-62 ........................................................................October 15, 2004
63-66 ......................................................................December 14, 1993
67...........................................................................January 27, 1995
68-70B.......................................................................October 15, 2004
71-74 ......................................................................December 14, 1993
74A-75.......................................................................October 15, 2004
76.........................................................................December 14, 1993
77...........................................................................October 15, 2004
78................................................................................July 8, 1996
79-81 ........................................................................October 15, 2004
SA1 .......................................................................December 14, 1993
SA2..........................................................................January 27, 1995
SA3..............................................................................July 8, 1996
SA4-SA26 ....................................................................October 15, 2004
A1-A2........................................................................October 15, 2004
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DECEMBER 14, 1993
(Title Page Reprinted: October 15, 2004)
1
UL 458
Standard for Power Converters/Inverters and Power Converter/Inverter
Systems for Land Vehicles and Marine Crafts
The first, second, and third editions were titled Power Converters and
Power-Converter Systems for Recreational Vehicles.
First Edition – February, 1977
Second Edition – May, 1986
Third Edition – November, 1991
Fourth Edition
December 14, 1993
The most recent designation of ANSI/UL 458 as an American National Standard
(ANSI) occurred on October 15, 2004. The ANSI approval does not include the
Cover Page, the Transmittal Pages, the Title Page, or Appendix A.
This ANSI/UL Standard for Safety, which consists of the Fourth Edition with
revisions through October 15, 2004, is under continuous maintenance, whereby
each revision is ANSI approved upon publication. Comments or proposals for
revisions on any part of the Standard may be submitted to UL at any time. Written
comments are to be sent to the UL-Northbrook Standards Department, 333
Pfingsten Road, Northbrook, IL 60062.
An effective date included as a note immediately following certain requirements
is one established by Underwriters Laboratories Inc. and is not part of the ANSI
Standard.
Revisions of this Standard will be made by issuing revised or additional pages
bearing their date of issue. A UL Standard is current only if it incorporates the
most recently adopted revisions, all of which are itemized on the transmittal notice
that accompanies the latest set of revised requirements.
ISBN 1-55989-212-9
COPYRIGHT © 1977, 2004 UNDERWRITERS LABORATORIES INC.
ANSI/UL458-2004

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CONTENTS
INTRODUCTION
1 Scope ...............................................................................7
2 Glossary .............................................................................8
3 Components ........................................................................12
4 General .............................................................................12
4.1 Units of Measurement ..........................................................12
4.2 Undated References ...........................................................12
PART I – POWER CONVERTERS AND INVERTERS
CONSTRUCTION
5 General ...........................................................................12A
6 Frame and Enclosure ...............................................................12A
7 Enclosures Used For Protected Environments ...........................................16
8 Accessibility of Uninsulated Live Parts, Film-Coated Wire, and Moving Parts ................17
8.1 General ......................................................................17
8.2 User servicing .................................................................19
8.3 Serviceman servicing ..........................................................20
9 Assembly ...........................................................................20
10 Protection Against Corrosion .........................................................21
11 Supply Connections .................................................................21
11.1 Permanently-connected converters or inverters ..................................21
11.2 Cord connection ............................................................24A
11.3 Bushings ...................................................................24B
12 Low-Voltage Output Connections and Wiring ...........................................25
12.1 General .....................................................................25
12.2 Cigarette lighter inputs ........................................................26
13 Secondary Circuits ..................................................................26
14 Live Parts ..........................................................................27
15 Internal Wiring ......................................................................28
15.1 General .....................................................................28
15.2 Tubing ......................................................................28
15.3 Protection of wiring ...........................................................29
15.4 Electrical connections .........................................................29
15.5 Separation of circuits .........................................................30
15.6 Barriers ....................................................................30A
16 Insulating Materials .................................................................31
17 Transformers .......................................................................31
17.1 General .....................................................................31
17.2 Coil insulation ................................................................31
18 Resistors ..........................................................................34
19 Switches and Controllers ............................................................34
20 Overload-Protective Devices .........................................................34
20.1 General .....................................................................34
20.2 Overcurrent-overtemperature protection .........................................35
21 Fuses and Fuseholders ..............................................................35
22 Receptacles ........................................................................36
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23 Inverter Output Circuits ..............................................................36
24 Lampholders ......................................................................36A
25 Capacitors ........................................................................36A
26 Transient Voltage Surge Suppressors ................................................36A
27 Printed Wiring .....................................................................36A
28 Spacings ..........................................................................37
28.1 General .....................................................................37
28.2 Insulation barriers ............................................................42
29 Grounding .........................................................................43
30 Bonding of Internal Parts ...........................................................44A
30.1 General ....................................................................44A
30.2 Bonding conductor ...........................................................45
PERFORMANCE
31 General ............................................................................45
32 Leakage Current Test ...............................................................45
33 Power Input Test ...................................................................49
34 Output Voltage Measurement Test ....................................................49
35 Capacitor Voltage Measurement Test .................................................49
36 Output Voltage and Current Test .....................................................50
37 Temperature Test ...................................................................50
37.1 Normal ......................................................................50
37.2 Maximum output without fan operation ..........................................55
37.3 Zero clearance ...............................................................55
37.4 Maximum overload without trip .................................................56
38 External Surface Temperature Limits Test .............................................56
39 Dielectric Voltage-Withstand Test .....................................................57
40 Induced Potential Test ...............................................................58
41 Testing on Transformer Insulating Materials ............................................58
42 Strain Relief Test ...................................................................58
43 Overload Test .....................................................................58A
44 Overcurrent Protection Calibration Test ................................................59
45 Ground-Fault Circuit-Interrupter Evaluation Test For Power Inverters ......................59
46 Battery Charger Overcharge Test .....................................................60
47 Abnormal Operation Test ............................................................60
47.1 General .....................................................................60
47.2 Output short-circuit ..........................................................60B
47.3 Switch position ...............................................................61
47.4 Component malfunction .......................................................61
47.5 Rectifier and capacitor short-circuit test .........................................61
47.6 Vibration test ................................................................61
47.7 Surge protectors .............................................................63
47.8 Specific value overload .......................................................63
47.9 Blanketing test ...............................................................64
47.10 Flanged bobbin transformer abnormal test .....................................64
47.11 Blocked fan ................................................................66
48 Evaluation of Reduced Spacings on Printed Wiring Boards ..............................66
48.1 General .....................................................................66
48.2 Dielectric voltage-withstand test ................................................66
48.3 Shorted trace test ............................................................67
49 Burnout Test .......................................................................67
49.1 General .....................................................................67
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49.2 Relay and solenoid burnout ....................................................67
49.3 Transformer burnout ..........................................................68
50 Gasket Tests .......................................................................69
51 Atomized Water Test ................................................................70
52 Label Adhesion Test ...............................................................70A
MANUFACTURING AND PRODUCTION TESTS
53 Dielectric Voltage-Withstand Test .....................................................71
54 Grounding Continuity Test ...........................................................73
RATING
55 General ............................................................................73
MARKING
56 Details .............................................................................74
57 Content ............................................................................74
58 Instruction Manual ..................................................................77
PART II – POWER-CONVERTER SYSTEMS
59 General ............................................................................77
CONSTRUCTION
60 Frame and Enclosure ...............................................................77
61 Power-Supply Assembly .............................................................78
62 Supply and Output Connections ......................................................78
63 Overcurrent Protection ..............................................................80
64 Transfer Switches .................................................................80A
65 Spacings .........................................................................80A
PERFORMANCE
66 Temperature Test ...................................................................81
MARKING
67 Details .............................................................................81
SUPPLEMENT SA - MARINE POWER CONVERTERS/INVERTERS AND POWER CONVERTER/
INVERTER SYSTEMS
INTRODUCTION
SA1 Scope ..........................................................................SA1
SA2 Glossary ........................................................................SA1
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CONSTRUCTION
SA3 General ........................................................................SA1
SA4 Frame and Enclosure ............................................................SA2
SA4.1 General ..................................................................SA2
SA4.2 Enclosures for open cockpit or weatherdeck mounting .........................SA2
SA5 Protection Against Corrosion ......................................................SA3
SA6 Supply Connections ..............................................................SA4
SA7 Internal Wiring And Grounding ....................................................SA5
SA8 Battery Connections .............................................................SA5
SA9 Ignition Protection ...............................................................SA5
SA10 Receptacles ...................................................................SA6
SA11 Arcing Parts ...................................................................SA6
SA12 Electrical Components ..........................................................SA6
PERFORMANCE
SA13 General .......................................................................SA6
SA13A Water Spray Test .............................................................SA6
SA13B Drip Test ....................................................................SA10
SA14 Leakage Current, Insulation Resistance, and Dielectric Voltage-Withstand (Repeated) .SA10
SA15 Salt Spray Corrosion Test ......................................................SA11
SA16 Output Voltage Control .........................................................SA11
SA17 Electrolyte Conditioning ........................................................SA12
SA18 Battery Discharge .............................................................SA12
SA19 Vibration .....................................................................SA12
SA20 Shock ........................................................................SA14
SA21 Ignition Protection .............................................................SA14
SA22 Metallic Coating Thickness .....................................................SA15
SA23 Accelerated Aging of Gaskets, Sealing Compounds and Adhesives .................SA17
SA24 Label Adhesion ...............................................................SA19
MARKING
SA25 Details .......................................................................SA19
INSTRUCTIONS
SA26 Instruction Manual .............................................................SA20
SA27 Important Safety Instructions ....................................................SA21
SA28 Assembly Instructions ..........................................................SA25
SA29 Operating Instructions ..........................................................SA25
SA30 Maintenance Instructions .......................................................SA26
APPENDIX A
Standards for Components..............................................................A1
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INTRODUCTION
1 Scope
1.1 These requirements cover fixed and stationary power converters, power-converter systems, and
accessories having a rated nominal input of 120, 120/240, or 240 volts, alternating current and a nominal
output of 24 volts or less, direct current. These converters are intended for use within land vehicles where
not directly exposed to outdoor conditions, and are intended to be employed in accordance with the
National Electrical Code, NFPA 70. 1.1 revised October 15, 2004
1.2 These requirements also cover fixed, stationary and portable power inverters and power-inverter
systems having a dc input and a 120 or 240 volts ac output. These inverters are intended for use within
land vehicles where not directly exposed to outdoor conditions, and are intended to be employed in
accordance with the National Electrical Code, NFPA 70.
1.2 effective April 13, 1993
1.3 These requirements also cover converters/inverters that are additionally intended to charge batteries.
1.3 effective April 13, 1993
1.4 Power converters covered by Part I of this standard are intended for connection to established 15-
and 20-ampere branch circuits within a recreational vehicle.
1.5 Power-inverters covered by Part I of this standard are intended for connection to a 12- or 24- volt dc
battery supply. 1.5 effective April 13, 1993
1.6 Power-converter systems and power-inverter systems covered by Part II of this standard are intended
for direct connection to a power-supply assembly and incorporate means for the connection of a maximum
of three line-voltage branch circuits only, not including the main disconnect. Power converter systems and
power inverter systems also employ circuitry as described in 1.4, and 1.5, or 1.5.
1.6 revised October 15, 2004
1.7 Power-converter systems and power-inverter systems shall also comply with the applicable
requirements for a Class CTL panelboard in the Standard for Panelboards, UL 67.
1.7 revised October 15, 2004
1.8 Converters and inverters incorporating provisions for the connection of more than three line-voltage
branch circuits are judged under the requirements in Part I of this standard and the applicable
requirements for a Class CTL panelboard in accordance with the Standard for Panelboards, UL 67.
1.8 effective April 13, 1993
1.8.1 Each pole of a multiple-pole circuit breaker is a separate circuit.
1.8.1 added October 15, 2004
1.9 A product that contains features, characteristics, components, materials, or systems new or different
from those covered by the requirements in this standard, and that involves a risk of fire, electric shock, or
injury to persons shall be evaluated using the appropriate additional component and end-product
requirements to determine that the level of safety as originally anticipated by the intent of this standard is
maintained. A product whose features, characteristics, components, materials, or systems conflict with
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specific requirements or provisions of this standard shall not be judged to comply with this standard.
Where appropriate, revision of requirements shall be proposed and adopted in conformance with the
methods employed for development, revision, and implementation of this standard.
1.9 revised September 11, 1998
2 Glossary
2.1 For the purpose of this standard the following definitions apply.
2.2 ACCESSIBLE PART – A part located so that it can be contacted by a person, either directly or by
means of a probe or tool during user servicing, or that is not recessed the required distance behind an
opening. 2.2 effective April 13, 1993
2.3 BARRIER – A partition for the insulation or isolation of electric circuits, for the isolation of electric
arcs, or for isolation of moving parts or hot surfaces. In this respect, a barrier may serve as a portion of
an enclosure or as a functional part. 2.3 effective April 13, 1993
2.4 BRANCH CIRCUIT – That portion of the wiring system beyond the final overcurrent protecting
device on the power-distribution panel protecting the circuit to the output.
2.4 effective April 13, 1993
2.5 CLASS 2 TRANSFORMER – A step-down, isolation type transformer having a secondary voltage of
not more than 30 volts rms (42.4 peak) under any condition of loading including open circuit and
complying with the applicable requirements in the Standard for Class 2 and Class 3 Transformers, UL
1585. 2.5 effective April 13, 1993
2.6 CONTROL CIRCUIT – A circuit that carries electric signals directing the performance of a controller
that, in turn, governs power delivered to a motor or other load in the equipment. A control circuit does
not carry main power current. 2.6 effective April 13, 1993
2.7 ENCLOSURE – That portion of a unit that reduces the accessibility and unintentional contact of a
part that may involve a risk of fire, electric shock or injury to persons, or reduces the risk of propagation
of flame, sparks, and molten metal initiated by an electrical disturbance occurring within.
2.7 effective April 13, 1993
2.8 FIELD-WIRING LEAD – Any lead to which a supply, load or other wire is intended to be connected
by an installer. 2.8 effective April 13, 1993
2.9 FIELD-WIRING TERMINAL – Any terminal to which a supply or other wire is intended to be
connected by an installer in the field is a field-wiring terminal unless the wire is provided as part of the
product and a pressure terminal, connector, soldering lug, soldered loop, crimped eyelet, or other
means for making the connection is factory-assembled to the wire.
2.9 effective April 13, 1993
2.10 FIXED UNIT – A unit that is intended to be permanently connected electrically.
2.10 effective April 13, 1993
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2.11 FLUSH-WALL-MOUNTED UNITS – Units that are intended to be recessed in a wall.
2.11 effective April 13, 1993
2.12 LIMITED-ENERGY CIRCUIT – A circuit having a voltage not exceeding 1000 volts and the energy
limited to 100 volt-amperes by a secondary winding of a transformer, or a fixed impedance.
2.12 effective April 13, 1993
2.13 LIVE PART – Denotes metal or conductive parts that, during intended use, have a potential
difference with respect to ground or any other conductive part.
2.13 effective April 13, 1993
2.14 LOW-VOLTAGE, LIMITED ENERGY CIRCUIT – A circuit involving an alternating voltage of not
more than 30 volts rms (42.4 volts peak) or a direct voltage of not more than 60 volts and supplied by:
a) An inherently limiting Class 2 transformer;
b) A non-inherently limiting Class 2 transformer and an overcurrent protective device that is:
1) Not of the automatic reclosing type;
2) Trip-free from the reclosing mechanism; and
3) Not readily interchangeable with a device of a different rating;
c) A combination of an isolated transformer secondary winding and a fixed impedance that
complies with all the performance requirements for an energy-limiting Class 2 transformer or
power source;
d) A dry-cell battery that is isolated from the primary circuit and having output characteristics no
greater than those of an energy-limiting Class 2 transformer or power source; or
e) A combination of a rechargeable battery and a fixed impedance that complies with all of the
performance requirements for an energy-limiting Class 2 transformer or power source.
2.14 effective April 13, 1993
2.15 PORTABLE POWER INVERTER – A power inverter that has no provisions for permanent
mounting or wiring, and can be easily carried or conveyed by hand.
2.15 revised October 15, 2004
2.16 POWER-CONVERTER OR POWER-INVERTER SYSTEM – An integral combination of a
converter or inverter, power-supply assembly, branch-circuit breakers, grounding bar, marking, and the
like, that are necessary for a complete installation.
2.16 effective April 13, 1993
2.17 POWER SUPPLY ASSEMBLY – Conductors, including grounding conductors insulated from each
other, connectors, attachment plugs, and all other fittings, grommets, or devices installed for the
purpose of delivering energy from a source of supply to a power-converter or inverter system of a land
vehicle or marine craft. 2.17 effective April 13, 1993
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2.18 PRESSURE TERMINAL CONNECTOR – A field wiring terminal that accomplishes the connection
of one or more conductors by means of pressure without the use of solder. A pressure terminal
connector may be the barrel and set screw type, crimp type barrel, or clamping plate and screw type.
2.18 effective April 13, 1993
2.19 PRIMARY CIRCUIT – Wiring and components that are conductively connected to a branch circuit
or an alternating-current motor generator set installed separately from, or included as, a part of a
power-converter or power-inverter system.
2.19 effective April 13, 1993
2.20 PRINTED WIRING BOARD – The finished combination of a pattern of conductive paths either on,
in, or both on and in (multilayer) a sheet of insulating material, including printed components, and the
base material. 2.20 effective April 13, 1993
2.21 PROTECTED ENVIRONMENT – Areas internal to the equipment that are resistant to entry of
carbon dust, or other conductive contaminants, and the like.
2.21 effective April 13, 1993
2.22 PROTECTED ENVIRONMENT ENCLOSURE – A part or total enclosure of an appliance that is
constructed as defined in Section 7, Enclosures Used for Protected Environments, so as to maintain a
protected environment. 2.22 effective April 13, 1993
2.23 RISK OF ELECTRICAL ENERGY - HIGH CURRENT LEVELS – The capability for damage to
property or injury to persons, other than by electric shock, from available electrical energy is considered
to exist, if between a live part and an adjacent dead metal part or between live parts of different
polarity, there exists a potential of 2 volts or more and either an available continuous power level of 240
volt-amperes or more, or a reactive energy level of 20 joules or more. For example, a tool, or other
metal short circuiting a component may cause a burn or a fire if enough energy is available at the
component to vaporize, melt, or more than warm the metal.
2.23 effective April 13, 1993
2.24 RISK OF ELECTRIC SHOCK – A risk of electric shock is considered to exist at any part if the
potential between the part and earth ground or any other accessible part is greater than 42.4 volts peak
ac or 60 volts dc, and the continuous current flow through a 1500 ohm resistor connected across the
potential exceeds 5 milliamperes. 2.24 effective April 13, 1993
2.25 RISK OF FIRE – A risk of fire is considered to exist at any component unless an investigation of
the supply delivering power to that component complies with the criteria in Section 6, Frame and
Enclosure. 2.25 effective April 13, 1993
2.26 RISK OF INJURY TO PERSONS – A condition that exists when stationary parts (such as sharp
metal edges and projections), moving parts (such as gears, chains, or linkages), falling objects,
inadequate mechanical strength of material, or the physical instability of the equipment are such that
injury to persons may result. 2.26 effective April 13, 1993
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2.27 SAFETY CIRCUIT – Any primary or secondary circuit that is relied upon to reduce the risk of fire,
electric shock, injury to persons, or electrical energy – high current levels. For example, in some
applications, an interlock circuit is considered to be a safety circuit.
2.27 effective April 13, 1993
2.28 SECONDARY CIRCUIT – A circuit conductively connected to the secondary winding of an
isolating power supply transformer. 2.28 effective April 13, 1993
2.29 SERVICE PERSONNEL – Trained persons having familiarity with the construction and operation
of the equipment, and the risks involved, who may periodically open an appliance to repair or maintain
electrical or mechanical components. 2.29 effective April 13, 1993
2.30 STAND ALONE UNITS – Units that are intended to be permanently mounted in place but not
recessed in the wall. 2.30 effective April 13, 1993
2.31 STATIONARY UNIT – Cord- and plug-connected units that are not fixed and are not movable. A
stationary unit may have provision for attachment in accordance with this standard.
2.31 effective April 13, 1993
2.32 POWER SUPPLY CORD – A separable cord set or a length of flexible cord or cable, with one end
connected to the primary-circuit wiring of the unit and the other end connected to the attachment plug
for connection to branch circuit power. 2.32 effective April 13, 1993
2.33 TOOL – A screwdriver, coin, key, or any other object that may be used to operate a screw latch,
or similar fastening means. 2.33 effective April 13, 1993
2.34 TRIP – Denotes automatic interruption of the electric circuit to the load.
2.34 effective April 13, 1993
2.35 USER SERVICING – Any form of servicing that can be performed by personnel other than those
who are trained to maintain the unit. Some examples of user servicing are:
a) The installation of accessories by means of attachment plugs and receptacles, or by means
of separable connectors.
b) The replacement of lamps and fuses, or the resetting of circuit breakers located in a user
access area unless they are marked to indicate replacement or resetting by qualified personnel
only.
c) The making of routine operating adjustments necessary to adapt the unit for different
intended functions.
d) Routine cleaning. 2.35 effective April 13, 1993
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3 Components
3.1 Except as indicated in 3.2, a component of a product covered by this standard shall comply with the
requirements for that component. See Appendix A for a list of standards covering components generally
used in the products covered by the standard.
3.1 revised October 15, 2004
3.2 A component is not required to comply with a specific requirement that:
a) Involves a feature or characteristic not required in the application of the component in the
product covered by this standard, or
b) Is superseded by a requirement in this standard.
3.2 revised October 15, 2004
3.3 A component shall be used in accordance with its rating established for the intended conditions of
use. 3.3 revised October 15, 2004
3.4 Specific components are incomplete in construction features or restricted in performance capabilities.
Such components are intended for use only under limited conditions, such as certain temperatures not
exceeding specified limits, and shall be used only under those specific conditions.
3.4 revised October 15, 2004
4 General
4.1 Units of Measurement
4.1.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or
approximate information.
4.2 Undated References
4.2.1 Any undated reference to a code or standard appearing in the requirements of this standard shall
be interpreted as referring to the latest edition of that code or standard.
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