1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 2748A Arcing Fault Interrupting Devices STANDARD FOR SAFETYUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL N
2、OT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Arcing Fault Interrupting Devices, UL 2748A First Edition, Dated August 29, 2017 Summary of Topics This First Edition of ANSI/UL 2748A, the Standard for Arcing Fault Interrupting Devices, cov
3、ers fast operating devices intended to interrupt currents associated with arcing faults, having interrupting times faster than conventional overcurrent devices. The new requirements are substantially in accordance with Proposal(s) on this subject dated April 28, 2017. All rights reserved. No part of
4、 this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, mechanical photocopying, recording, or otherwise without prior permission of UL. UL provides this Standard as is without warranty of any kind, either expressed or implied, includin
5、g but not limited to, the implied warranties of merchantability or tness for any purpose. In no event will UL be liable for any special, incidental, consequential, indirect or similar damages, including loss of prots, lost savings, loss of data, or any other damages arising out of the use of or the
6、inability to use this Standard, even if UL or an authorized UL representative has been advised of the possibility of such damage. In no event shall ULs liability for any damage ever exceed the price paid for this Standard, regardless of the form of the claim. Users of the electronic versions of ULs
7、Standards for Safety agree to defend, indemnify, and hold UL harmless from and against any loss, expense, liability, damage, claim, or judgment (including reasonable attorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronic Standard on the purchasers c
8、omputer system. AUGUST 29, 2017 UL 2748A tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL AUGUST 29, 2017 UL 2748A tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION F
9、ROM UL AUGUST 29, 2017 1 UL 2748A Standard for Arcing Fault Interrupting Devices Prior to the rst edition, the requirements for the products covered by this standard were included in the Outline of Investigation for Arcing Fault Interrupting Devices, UL 2748A. First Edition August 29, 2017 This ANSI
10、/UL Standard for Safety consists of the First Edition. The most recent designation of ANSI/UL 2748A as an American National Standard (ANSI) occurred on August 29, 2017. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, and Title Page. Comments or proposals for revision
11、s 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 electronic copy of a Standard shou
12、ld 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 2017 UNDERWRITERS LABORATORIES INC. ANSI/UL 2748A-2017UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR D
13、ISTRIBUTION WITHOUT PERMISSION FROM UL AUGUST 29, 2017 ARCING FAULT INTERRUPTING DEVICES - UL 2748A 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 Components4 3 Units of Measurement .
14、5 4 Undated References 5 5 Glossary .5 CONSTRUCTION 6 General 6 7 Creepage and Clearance Distance 6 8 Wiring .7 9 Operation 7 PERFORMANCE 10 General.8 11 Continuous Current Test .8 12 Power-Frequency Withstand Voltage Tests .9 13 Internal Arcing Fault Test 9 14 Arcing Fault Interruption Test.10 RATI
15、NGS 15 General10 MARKING 16 General11 INSTRUCTIONS 17 General11 AUGUST 29, 2017 ARCING FAULT INTERRUPTING DEVICES - UL 2748A 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover fast operating de
16、vices intended to interrupt currents associated with arcing faults, having interrupting times faster than conventional overcurrent devices. 1.2 These requirements cover open type devices that are intended to be installed within power distribution equipment. 1.3 These requirements cover devices rated
17、 up to 52 kV ac maximum. 1.4 This standard does not include the requirements for sensors intended to detect arcing faults, devices intended to trigger the functioning of the arc interrupting device, or devices intended to quench arcing faults by transferring the arcing fault to a lower impedance pat
18、h. 1.5 This standard does not include requirements for integration and testing of arcing fault interrupting devices within equipment it is intended to protect. 2 Components 2.1 Except as indicated in 2.2, a component of a product covered by this standard shall comply with the requirements for that c
19、omponent. 2.2 A component is not required to comply with a specic 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. 2.3 A component shall be used i
20、n accordance with its rating established for the intended conditions of use. 2.4 Specic 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
21、 limits, and shall be used only under those specic conditions. AUGUST 29, 2017 ARCING FAULT INTERRUPTING DEVICES - UL 2748A 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 3 Units of Measurement 3.1 Values stated without parentheses are the
22、 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 interpreted as referring to the latest edition of that code or standard. 5 Glossary 5.1 For the
23、 purpose of this standard, the following denitions apply. 5.2 ARCING FAULT A non-intentional discharge of electrical energy in air or other gas, including discharges across the surface of an insulating material. 5.3 INTERRUPTING DEVICE A device that is used to interrupt an arcing fault. 5.4 LOW-VOLT
24、AGE A voltage of 1000 V ac or less. 5.5 MEDIUM-VOLTAGE A voltage of greater than 1000 V ac, up to 52 kV ac. 5.6 OPEN TYPE DEVICE A device not provided with an overall enclosure. An open type device is intended to be eld installed within an end-product equipment enclosure. 5.7 POLLUTION DEGREE 2 MICR
25、OENVIRONMENT An area where normally only nonconductive pollution occurs, but where occasional, temporary conductivity may be expected. Typical constructions that reduce the possibilities of conductive pollution and condensation or high humidity are: a) Non-ventilated enclosures that are provided wit
26、h continuous application of heat through the use of heaters or through continuous energization of the device, with interruptions such that cooling to the point of condensation does not occur; or b) The use of ventilated enclosures where all openings are provided with lters. 5.8 RESETTABLE Capable of
27、 being returned to a closed position by pushing a button, moving a handle, or similar means. Devices that cannot possibly be returned to a closed position without replacing parts using special tools are not considered resettable. 5.9 STANDARD PROTECTIVE DEVICE A fuse, circuit breaker, or other devic
28、e that provides protection against overcurrents and that complies with standards that dene the operating characteristics for the overcurrent device. AUGUST 29, 2017 ARCING FAULT INTERRUPTING DEVICES - UL 2748A 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT P
29、ERMISSION FROM UL CONSTRUCTION 6 General 6.1 Other than as noted in 6.2, interrupting devices that are intended to directly replace standard protective devices shall comply with the dimensional requirements for the standard protective device that will be replaced. 6.2 Interrupting devices that are i
30、ntended to directly replace standard protective devices may have overall dimensions that differ from standard device that will be replaced, providing the dimensional changes do not affect the electrical connections or mounting of the device when the replacement is made. 6.3 Interrupting devices that
31、 are not direct replacements for standard protective devices shall not have dimensions that would allow the device to be inserted in place of a standard protective device. 7 Creepage and Clearance Distance 7.1 A device intended to replace a standard protective device shall comply with the creepage a
32、nd clearance distance requirements of the standard used to investigate the standard protective device. 7.2 Creepage and clearance distances within low-voltage control circuits of interrupting devices shall comply with the creepage and clearance distance requirements of the Standard for Industrial Co
33、ntrol Equipment, UL 508. Creepage and clearance distances between low-voltage control circuits and medium voltage control circuits shall be no less than the creepage and clearance distances required from the low-voltage circuit to grounded metal, and shall also be sufficient to meet the dielectric r
34、equirements specied in this standard for the maximum voltage rating of the device, with the control circuits grounded during testing. 7.3 For printed wiring boards, the creepage and clearance distances shall comply with requirements of the Standard for Insulation Coordination Including Clearances an
35、d Creepage Distances for Electrical Equipment, UL 840. For the purpose of this investigation, interrupting devices shall be considered to be located within circuits of overvoltage category 3. All interrupting devices are considered to be installed in pollution degree 3 environments, except for porti
36、ons of the device located in a pollution degree 2 microenvironment. 7.4 Pollution Degree 2 shall be considered to exist on a printed-wiring board where a coating provides an uninterrupted covering of the conductive material for at least one of two conductive materials and covers the entire space bet
37、ween the two conductive materials for which the spacing is being evaluated. AUGUST 29, 2017 ARCING FAULT INTERRUPTING DEVICES - UL 2748A 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 8 Wiring 8.1 Insulated conductors provided as part of a
38、n interrupting device shall be rated for the particular application and shall have an ampacity no less than the maximum current rating of the circuit to which they are connected. 8.2 Wiring shall be located or protected to prevent contact with any sharp edge or moving part that could damage the insu
39、lation. 8.3 Insulated conductors shall be separated from wiring and uninsulated live parts connected to other circuits, unless both circuits are provided with insulation rated for the highest voltage. 9 Operation 9.1 Interrupting devices with adjustable sensitivity shall comply with the requirements
40、 of this standard over the entire range of possible settings. 9.2 Interrupting devices that have provisions for disabling the arcing fault interrupting function shall have provisions for local and remote indication that the device has been disabled. Devices with provisions for intentionally delaying
41、 the time between detection of an arcing fault and operation of the arcing fault interrupting function shall have provisions for local and remote indication that operation of the interrupting function will be intentionally delayed. 9.3 Interrupting devices that can be reset after an arcing fault has
42、 been interrupted shall be provided with visual indication that the device has operated under an arcing fault condition and shall also have provisions for remote indication of arcing fault interruption function operation. 9.4 Devices that cannot be reset after an arcing fault interruption, and must
43、be replaced after interruption (such as a fusible element) are not required to have such indication that the device has interrupted an arcing fault. 9.5 Interrupting devices that are resettable, shall be marked in accordance with 16.5. Devices that cannot be reset after an arcing fault interruption,
44、 and must be replaced after interruption (such as a fusible element) are not required to have such indication that the device has interrupted an arcing fault. AUGUST 29, 2017 ARCING FAULT INTERRUPTING DEVICES - UL 2748A 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION
45、 WITHOUT PERMISSION FROM UL PERFORMANCE 10 General 10.1 Interrupting devices that are intended to directly replace standard protective devices shall comply with performance requirements for that standard protective device, including the required time-current characteristics for overloads other than
46、arcing faults. 10.2 Interrupting devices shall comply with the requirements of Sections 11 14 with the interrupting device installed and connected in accordance with the manufacturers installation instructions. 10.3 Interrupting devices with adjustable settings shall be tested to demonstrate complia
47、nce with the performance requirements over the range of possible settings, including minimum and maximum settings. 11 Continuous Current Test 11.1 Devices intended to replace standard protective devices shall comply with the continuous current (temperature) test as required by the standard for the s
48、tandard protective device. 11.2 Low-voltage interrupting devices that are not intended to replace standard protective devices shall be subjected to a continuous current test in accordance with For Switchgear Metal-Enclosed Low-Voltage AC Power Circuit Breaker Switchgear Assemblies Conformance Test P
49、rocedures, ANSI/IEEE C37.51. During the continuous current test, the device shall operate without exceeding the allowable temperature limits specied in Tables 3 and 4 of Metal-Enclosed Low-Voltage (1000 Vac and below, 3200 Vdc and below) Power Circuit Breaker Switchgear, ANSI/IEEE C37.20.1, and in the Table for Maximum temperature rise and the Table for Maximum enclosure surface temperature rises of the Standard for Industrial Control Equipment, UL 508. 11.3 Medium-voltage interrupting devices that are not i
