1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 840 Insulation Coordination Including Clearances and Creepage Distances for Electrical Equipment STANDARD FOR SAFETYUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIB
2、UTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Insulation Coordination Including Clearances and Creepage Distances for Electrical Equipment, UL 840 Third Edition, Dated January 6, 2
3、005 Summary of Topics This revision to ANSI/UL 840 includes an updated title page to reect reaffirmation of ANSI approval. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. Changes in requirements are marked with a
4、vertical line in the margin and are followed by an effective date note indicating the date of publication or the date on which the changed requirement becomes effective. The revised requirements are substantially in accordance with Proposal(s) on this subject dated August 19, 2016. All rights reserv
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9、e purchasers computer system. OCTOBER 5, 2016 UL 840 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL OCTOBER 5, 2016 UL 840 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PE
10、RMISSION FROM UL JANUARY 6, 2005 (Title Page Reprinted: October 5, 2016) 1 UL 840 Standard for Insulation Coordination Including Clearances and Creepage Distances for Electrical Equipment First Edition December, 1984 Second Edition May, 1993 Third Edition January 6, 2005 This ANSI/UL Standard for Sa
11、fety consists of the Third Edition including revisions through October 5, 2016. The most recent designation of ANSI/UL 840 as a Reaffirmed American National Standard (ANS) occurred on October 5, 2016. ANSI approval for a standard does not include the Cover Page, Transmittal Pages and Title Page. Com
12、ments or proposals for revisions on any part of the Standard may be submitted to UL at any time. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) at https:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor ele
13、ctronic copy of a Standard should be altered in any way. All of ULs Standards and all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2016 UNDERWRITERS LABORATORIES INC. ANSI/UL 840-2012 (R2016)UL COPYRIGHTED MATERIAL NOT AUT
14、HORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL MAY 4, 2012 UL 840 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .4 2 Glossary .5 3 Units of Measurement 6A 4 U
15、ndated References .6A 5 Components 6A 6 Insulation Coordination 7 CONSTRUCTION 7 Clearance A (Equivalency) .9 8 Clearance B (Controlled Overvoltage) 10 9 Creepage Distances .12 10 Measurement of Clearance and Creepage Distances .15 11 Use of Coatings to Achieve Insulation Coordination 23 PERFORMANCE
16、 12 Switching Test 23 13 Recurring Peak Voltage Determination .23 14 Dielectric Voltage-Withstand Tests .24 14.1 Testing in lieu of measuring clearances 24 14.2 Testing for controlled overvoltage .25 15 Printed Wiring Board Coating Performance Test 25 15.1 General .25 15.2 Dielectric voltage-withsta
17、nd test .27 15.3 Environmental cycling test 28 15.4 Humidity conditioning test 28 15.5 Thermal conditioning test .28 15.6 Coating adhesion .30 15.7 Insulation resistance between conductors 30 15.8 Impulse withstand voltage 31 15.9 Resistance to soldering heat 31 15.10 Flammability .31 15.11 Comparat
18、ive tracking index (CTI) .31 MAY 4, 2012 UL 840 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover an alternate approach to specifying through air and over surface spacings for electrical equip
19、ment through the use of the principles of insulation coordination. 1.2 The complete principles of insulation coordination involve the consideration of the combination of clearances, creepage distances, and the properties of solid insulation used to constitute the insulation system. The empirical dat
20、a gathered thus far has been used to develop the requirements for clearances and creepage distances as presented in this standard. The data needed to develop the evaluation procedure for solid insulation is still being gathered. When available, this evaluation procedure will be added to this standar
21、d and is not expected to affect the requirements for clearances and creepage distances. 1.3 These requirements may be used as an alternate to required spacing levels specied in end-product standards. The end product standard spacing requirements may be based on use and systems where overvoltages are
22、 not controlled, or if controlled, the level of control is unknown. 1.4 These alternate requirements are intended to be applied to a particular product category if the standard covering the product category specically references UL 840 or any of the requirements therein. 1.5 Users of these requireme
23、nts may need to specify the overvoltage levels and the methods of control which will be utilized, and establish the pollution degree to which the product insulation system will be expected to be subjected. 1.6 It is not intended that the test values in this standard be employed for production line t
24、esting. However, users of these requirements will need to establish a means to ensure that production controls applied to permit the spacing reduction remain in effect during the manufacture of the product. This could include sample testing or physical measurements or another equivalent means. 1.7 U
25、sers of these requirements will additionally need to ensure that inuencing factors not addressed in this standard, such as mechanical movement, eld placement of conductive material, and product damage, will not affect the system for insulation coordination. Examples are the deformation of the enclos
26、ure, movement of the ttings for conduit or armored cable, or the improper installation of eld wiring. Clearances and creepage distances at those locations must be veried for compliance by physical measurement in accordance with Section 10, Measurement of Clearance and Creepage Distances. JANUARY 6,
27、2005 UL 840 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 2 Glossary 2.1 For the purpose of this standard, the following denitions apply. 2.2 CLEARANCES Through air spacing. 2.2A COMBINATION WAVEFORM A surge delivered by a generator which
28、 has the inherent capability of applying a 1.2/50 s voltage wave across an open circuit, and delivering an 8/20 s current wave into a short circuit. Also called a combination surge. 2.2A added May 4, 2012 2.3 CREEPAGE DISTANCES (CREEPAGES) Over surface spacings. 2.4 FUNCTIONAL OVERVOLTAGE Deliberate
29、ly imposed transient overvoltages necessary for the function of a device. 2.5 GENERAL ENVIRONMENT The overall area or space in which the equipment is located. Commonly referred to as ambient conditions. 2.6 IMPULSE WITHSTAND VOLTAGE The highest peak value of impulse voltages, of prescribed form and
30、polarity, that does not cause breakdown under specied conditions of test. 2.7 INSULATION COORDINATION The correlation of insulating characteristics of electrical equipment: a) With expected overvoltages and characteristics of overvoltage protective devices (a key consideration for clearances); and b
31、) With the expected micro-environment and pollution protective means (key considerations for creepage distances). 2.8 LEAKAGE CURRENT The current that can be measured as owing between test points during a dielectric voltage-withstand test. 2.9 LIGHTNING OVERVOLTAGE The transient overvoltage at a giv
32、en location on a system due to a specic lightning discharge. 2.10 MICRO-ENVIRONMENT The conditions that immediately surround the clearance or creepage distance under consideration. The micro-environment of the creepage distance or clearance and not the general environment of the equipment determines
33、 the effect on the insulation. The micro-environment might be less severe or more severe than the general environment that the equipment is in. It includes all factors inuencing the insulation, such as climatic, electromagnetic, and generation of pollution. 2.10A NOMINAL DISCHARGE CURRENT (In) Peak
34、value of the current, selected by the manufacturer, through the SPD having a current waveshape of 8/20 where the SPD remains functional after 15 surges. 2.10A added May 4, 2012 2.11 OPERATING VOLTAGE The voltage across two points occurring due to normal operation of the product when controls are set
35、 in any position. MAY 4, 2012 UL 840 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 2.12 OVERVOLTAGE CATEGORY Grouping of products based on typical installed location with respect to overvoltage protection and available energy. See note c
36、of Table 8.1. 2.13 POLLUTION Any addition of contaminants, solid, liquid or gaseous (ionized gases), and moisture that may produce a reduction of dielectric strength or surface resistivity. 2.14 POLLUTION DEGREE The level of pollution present at the location on or in a product where the clearance an
37、d creepage distance measurement is made, and can be controlled by design of the product. For example, enclosures can be used to achieve pollution degree 3, heaters within enclosures can help achieve pollution degree 2, and encapsulation can be used to achieve pollution degree 1. See 9.3. 2.15 RATED
38、VOLTAGE The voltage employed for test purposes by the end-product standard. 2.16 RECURRING PEAK VOLTAGE Deliberately or naturally imposed transient overvoltage that exceeds the steady state voltage, and is caused by operating a control or adjustable component. The voltage level will be consistent fo
39、r the same operation under the same conditions. Insulating materials can be degraded by ozone generated by partial discharges due to recurring peak voltages. 2.16A SURGE PROTECTIVE DEVICE (SPD) TYPE DESIGNATIONS SPD Type designations are as follows: TYPE 1 Permanently connected SPDs intended for ins
40、tallation between the secondary of the service transformer and the line side of the service equipment overcurrent device, as well as the load side, including watt-hour meter socket enclosures and intended to be installed without an external overcurrent protective device. TYPE 2 Permanently connected
41、 SPDs intended for installation on the load side of the service equipment overcurrent device - including SPDs located at the branch panel. TYPE 3 Point of utilization SPDs, installed at a minimum conductor length of 10 meters (30 feet) from the electrical service panel to the point of utilization, f
42、or example cord connected, direct plug-in, receptacle type and SPDs installed at the utilization equipment being protected. The distance of 10 meters (30 feet) is exclusive of conductors provided with or used to attach SPDs. TYPE 4 COMPONENT ASSEMBLIES Component assembly consisting of one or more Ty
43、pe 5 components together with a disconnect (integral or external) or a means of complying with the limited current tests. TYPE 1, 2, 3 COMPONENT ASSEMBLIES Consists of a Type 4 component assembly with internal or external short circuit protection. TYPE 5 Discrete component surge suppressors, such as
44、 MOVs that may be mounted on a PWB, connected by its leads or provided within an enclosure with mounting means and wiring terminations. 2.16A added May 4, 2012 2.17 SWITCHING OVERVOLTAGE The transient overvoltage at a given location on a system due to a specic switching operation or fault. 2.18 SYST
45、EM VOLTAGE The rated supply or line voltage to which the product will be connected. MAY 4, 2012 UL 840 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 2.19 TRANSIENT OVERVOLTAGE Nonperiodic voltages that may be caused by switching, lightnin
46、g, or function of a device. 3 Units of Measurement 3.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information. 4 Undated References 4.1 Any undated reference to a code or standard appearing in the requirements of this standard shall be
47、 interpreted as referring to the latest edition of that code or standard. 5 Components 5.1 Except as indicated in 5.2, a component of a product covered by this standard shall comply with the requirements for that component. 5.2 A component is not required to comply with a specic requirement that: a)
48、 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. 5.3 A component shall be used in accordance with its rating established for the intended conditions of use. 5.4 Speci
49、c 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 specied limits, and shall be used only under those specic conditions. MAY 4, 2012 UL 840 6AUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL MAY 4, 2012 UL 840 6B No Text on This PageUL COPYRIGHTED MATER
