1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 917 Clock-Operated SwitchesUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPROD
2、UCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Clock-Operated Switches, UL 917 Fifth Edition, Dated November 10, 2006 Summary of Topics The revisions dated August 15, 2013 are being issued to adopt the following proposals: 1. Addition Of The Abnormal Operations Test Tex
3、t 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 vertical line in the margin and are followed by an effective date note indicating the date of publication or the date on which
4、 the changed requirement becomes effective. The new/revised requirements are substantially in accordance with Proposal(s) on this subject dated April 12, 2013. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, e
5、lectronic, 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, including but not limited to, the implied warranties of merchantability or tness for any purpose. In no event will UL
6、 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 inability to use this Standard, even if UL or an authorized UL representative has been advised of the possibi
7、lity 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 Standards for Safety agree to defend, indemnify, and hold UL harmless from and against any loss, expense, lia
8、bility, 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 computer system. The requirements in this Standard are now in effect, except for those paragraphs, sections, t
9、ables, gures, and/or other elements of the Standard having future effective dates as indicated in the note following the affected item. The prior text for requirements that have been revised and that have a future effective date are located after the Standard, and are preceded by a SUPERSEDED REQUIR
10、EMENTS notice. AUGUST 15, 2013 UL 917 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL AUGUST 15, 2013 UL 917 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM U
11、L NOVEMBER 10, 2006 (Title Page Reprinted: August 15, 2013) 1 UL 917 Standard for Clock-Operated Switches First Edition August, 1974 Second Edition April, 1977 Third Edition May, 1985 Fourth Edition July, 1994 Fifth Edition November 10, 2006 This UL Standard for Safety consists of the Fifth Edition
12、including revisions through August 15, 2013. Comments 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 http:/. ULs Standards for Safety a
13、re copyrighted by UL. Neither a printed nor electronic 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 2013 UNDERWRITERS LABORATORIES INC.UL COPYRI
14、GHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL NOVEMBER 10, 2006 CLOCK-OPERATED SWITCHES - UL 917 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION
15、1 Scope .6 2 Glossary .6 3 Components 7 4 Units of Measurement .7 5 References .8 CONSTRUCTION 6 Frame and Enclosure 8 6.1 General .8 6.2 Nonmetallic .10 6.3 Cast metal 11 6.4 Sheet metal 11 6.5 Covers .13 6.6 Openings .14 6.7 Screens and expanded metal .16 6.8 Conduit openings 16 7 Rainproof Enclos
16、ures .17 8 Mounting 18 8.1 General 18 8.2 Plug-in devices 19 9 Assembly .21 10 Operating Mechanism .22 11 Corrosion Protection 22 12 Insulating Material 23 13 Field Connections .23 14 Supply Connections .23 14.1 Permanently connected devices 23 14.2 Connections for wiring systems 24 14.3 Terminals .
17、25 15 Cord-Connected Devices 26 15.1 Cords and plugs .26 15.2 Polarization 26 15.3 Strain relief 27 15.4 Bushings 27 16 Grounding .27 17 Receptacles 28 18 Bonding of Internal Parts 29 18.1 General .29 18.2 Construction and connection .30 19 Current-Carrying Parts 30 20 Internal Wiring 31 21 Coil Win
18、dings 32 22 Spacings 32 23 Field-Wiring Space 35 NOVEMBER 10, 2006 CLOCK-OPERATED SWITCHES - UL 917 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL PERFORMANCE 24 General 35 25 Leakage Current Test .35 26 Temperature Test .37 27 Overload Te
19、st 41 28 Endurance Test 44 29 Tungsten-Filament-Lamp Load Test .45 30 Test Conditions .47 31 Rain Test 47 32 Dielectric Voltage-Withstand Test .50 33 Impact Test 51 34 Metallic Coating Thickness Test 51 35 Gasket Tests .53 36 Grounding Resistance Test 53 37 Strain Relief Test .53 38 Snap-On Cover Te
20、sts .54 39 Knockout Secureness Test .54 40 Humidity Test 54 41 Abnormal Operation Test 54 41.1 Adverse conditions of operation 54 41.2 Abnormal Switching Test .54A RATINGS 42 Details .55 MARKINGS 43 Details .55 TV RATED SWITCHES GENERAL 44 Details .57 CONSTRUCTION 45 Enclosure 58 45.1 General .58 45
21、.2 Insulating material 58 45.3 Switch enclosure openings 58 45.4 Wire leads .58 PERFORMANCE 46 General 59 47 Test Circuit 59 48 Test Conditions .60 49 Overload Test 60 50 Endurance Test 60 51 Temperature Test .60 AUGUST 15, 2013 CLOCK-OPERATED SWITCHES - UL 917 4UL COPYRIGHTED MATERIAL NOT AUTHORIZE
22、D FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 52 Dielectric Voltage-Withstand Test .61 53 Continued Endurance Test .61 AUGUST 15, 2013 CLOCK-OPERATED SWITCHES - UL 917 4AUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL
23、 AUGUST 15, 2013 CLOCK-OPERATED SWITCHES - UL 917 4B No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 54 Dielectric Voltage-Withstand Test (Repeated) 61 RATINGS 55 Details .61 MARKINGS 56 Details .61 NOVEMBER 10, 2006 CLOC
24、K-OPERATED SWITCHES - UL 917 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover clock-operated switches rated 600 V or less, to be used in ordinary locations designed to close and open circuits
25、 to a load at predetermined intervals, and intended to be employed in accordance with the National Electrical Code, ANSI/NFPA 70. 1.2 These requirements cover only clock-operated switches in which the switching contacts are actuated by a clock-work, by a gear-train, by hand, by electrically-wound sp
26、ring motors, by electric clock-type motors, or by equivalent arrangements. In addition to closing and opening the switching contacts, the devices may also indicate the time of day or time interval. 1.3 These requirements do not cover devices incorporating electronic timing circuits or switching circ
27、uits without separable contacts. 1.4 A clock-operated switch, which is incomplete in construction features or restricted in performance capabilities, is acceptable for use as a factory-installed component provided that the restrictions established for the component are eliminated when the component
28、is installed. 1.5 Specic provisions are included in these requirements for TV rated clock-operated switches. 1.6 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 r
29、e, electric shock, or injury to persons shall be evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the acceptable level of safety as originally anticipated by the intent of this Standard. A product whose features, characteristics, c
30、omponents, materials, or systems conict with specic requirements or provisions of this Standard cannot be judged to comply with this Standard. Where considered appropriate, revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and
31、implementation of this Standard. 2 Glossary 2.1 For the purpose of this standard the following denitions apply. 2.2 ACCESSIBLE PART A part so located that it can be contacted by a person, either directly or by means of a probe or tool. 2.3 LEAKAGE CURRENT Leakage current refers to all currents, incl
32、uding capacitively coupled currents, that may be conveyed between exposed conductive surfaces of an appliance and ground or other exposed conductive surfaces of a device. 2.4 LIVE PARTS Denotes metal or other conductive parts that have a potential difference with respect to ground or any other condu
33、ctive part in intended use. 2.5 LOW-VOLTAGE CIRCUIT A circuit classied as low voltage is one involving a potential of not more than 42.4 V peak (30 V rms) and supplied by a primary battery, by a standard Class 2 transformer, or by a combination of a transformer and a xed impedance, which, as a unit,
34、 complies with all the performance requirements for a Class 2 transformer. 2.6 OPERATING CONTROL A control, usually a knob, push button, or lever, provided to enable the user to cause the device to perform its intended function, without the use of tools, when the device is in the operating condition
35、. NOVEMBER 10, 2006 CLOCK-OPERATED SWITCHES - UL 917 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 2.7 PERMANENTLY CONNECTED Denotes connection to a supply circuit by way of xed electrical conductors. 2.8 PILOT DUTY An application involvi
36、ng the control of an electromagnet. 2.9 PLUG-IN DEVICE A device provided with integral blades for direct insertion into a receptacle. 2.10 RAINPROOF So constructed, protected, or treated as to prevent rain from interfering with successful operation of the device under specied test conditions. 2.11 S
37、WITCH Usage of the word switch without further qualication signies a clock-operated switch in subsequent paragraphs of this standard. 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. 3.2 A component
38、need not comply with a specic requirement that: a) Involves a feature or characteristic not needed in the application of the component in the product covered by this standard, or b) Is superseded by a requirement in this standard. 3.3 A component shall be used in accordance with its recognized ratin
39、g established for the intended conditions of use. 3.4 Specic components are recognized as being 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
40、 and shall be restricted to use only under those specic conditions for which they have been recognized. 4 Units of Measurement 4.1 If a value for measurement is followed by a value in other units in parentheses, the second value may be only approximate. The rst stated value is the requirement. NOVEM
41、BER 10, 2006 CLOCK-OPERATED SWITCHES - UL 917 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 5 References 5.1 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to t
42、he latest edition of that code or standard. CONSTRUCTION 6 Frame and Enclosure 6.1 General 6.1.1 The frame and enclosure shall be strong and rigid to resist the abuses likely to be encountered during service. The degree of structural integrity inherent in the unit shall preclude total or partial col
43、lapse with the attendant reduction of spacings, loosening or displacement of parts, and other serious defects that alone or in combination constitute an increase in the risk of re, electric shock, or injury to persons. 6.1.2 Electrical parts of a clock-operated switch shall be located or enclosed to
44、 reduce the risk of unintentional contact with an uninsulated live part. For the purpose of these requirements, lm-coated wire is considered to be an uninsulated live part. Exception: An enclosure is not required for a device intended for assembly as part of another device. 6.1.3 An opening in an en
45、closure or a clock-operated switch is acceptable if an accessibility probe as illustrated in Figure 6.1, when inserted into the opening, cannot be made to touch any part that involves the risk of electric shock to the end-user or service personnel. However, in no case shall the opening be large enou
46、gh to permit the entrance of a 1 inch (25.4 mm) diameter rod. This is generated text for gtxt. NOVEMBER 10, 2006 CLOCK-OPERATED SWITCHES - UL 917 8UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL Figure 6.1 Accessibility probe NOVEMBER 10, 20
47、06 CLOCK-OPERATED SWITCHES - UL 917 9UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 6.1.4 The accessibility probe shall be articulated into any conguration and shall be rotated or angled to any position before, during, or after insertion in
48、to the opening, and the penetration shall be to any depth allowed by the opening size, including minimal depth combined with maximum articulation. 6.1.5 If any part of the enclosure must be opened or removed as part of normal operation, regular adjustment, or regular or required maintenance (set poi
49、nt adjustment, timer or time of day clock adjustment, battery replacement, and the like) with or without the use of tools, or can be opened or removed without the use of tools, the accessibility probe is to be applied without the part in place. Exception: An enclosure employing a snap-on cover as indicated in 6.5.2 need not comply with this requirement. 6.1.6 Moving parts of a switch such as rotors of motors, clock works, or gear trains, shall be located or enclosed to reduce the
