1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 923 Microwave Cooking AppliancesUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER R
2、EPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Microwave Cooking Appliances, UL 923 Seventh Edition, Dated May 1, 2013 Summary of Topics The revisions dated November 18, 2015, were issued to add requirements for Polymeric Materials and make editorial changes. The n
3、ew and revised requirements are substantially in accordance with Proposal(s) on this subject dated June 19, 2015 and September 25, 2015. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. All rights reserved. No part
4、 of 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, inclu
5、ding 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 t
6、he 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 U
7、Ls 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 purchaser
8、s computer system. NOVEMBER 18, 2015 UL 923 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL NOVEMBER 18, 2015 UL 923 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSIO
9、N FROM UL May 1, 2013 (Title Page Reprinted: November 18, 2015) 1 UL 923 Standard for Microwave Cooking Appliances First Edition October, 1977 Second Edition November, 1981 Third Edition August, 1990 Fourth Edition November, 1995 Fifth Edition May, 2002 Sixth Edition April, 2008 Seventh Edition May
10、1, 2013 This ANSI/UL Standard for Safety consists of the Seventh Edition including revisions through November 18, 2015. The most recent designation of ANSI/UL 923 as an American National Standard (ANSI) occurred on November 18, 2015. ANSI approval for a standard does not include the Cover Page, Tran
11、smittal Pages and Title Page. The Department of Defense (DoD) has adopted UL 923 on June 29, 1990. The publication of revised pages or a new edition of this Standard will not invalidate the DoD adoption. Comments or proposals for revisions on any part of the Standard may be submitted to UL at any ti
12、me. Proposals should be submitted via a Proposal Request in ULs On-Line Collaborative Standards Development System (CSDS) at http:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way. All of ULs Standards and all copyrigh
13、ts, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT 2015 UNDERWRITERS LABORATORIES INC. ANSI/UL 923-2015UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL NOVEMBER 18, 2015 MICROWAV
14、E COOKING APPLIANCES - UL 923 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .9 2 Glossary .9 CONSTRUCTION 3 General .13 4 Components 13 5 Frame and Enclosure .14A 6 Accessibility of Live
15、Parts .16 7 Protection Against Injury 20 7.1 General 20 7.2 Strength of mounting 21 7.3 Fans .21 8 Mechanical Assembly 21 9 Protection Against Corrosion 22 10 Interlocks 22 11 Interlock Monitors .23 12 Polymeric Materials .23 13 Supply Connections .26D 13.1 Permanently-connected appliances .26D 13.2
16、 Cord-connected appliances 29 14 Live Parts 31 15 Polarization 32 16 Internal Wiring 32 16.1 General .32 16.2 Splices and connections 35 17 Heating Elements .36 18 Electrical Insulation .37 18.1 General .37 18.2 Printed wiring board 38 18.3 Film-coated wire (magnet wire) 38 18.4 Insulation systems 3
17、8 19 Thermal Insulation 39 20 Motors .39 21 Motor Overload Protection .40 22 Short-Circuit and Ground-Fault Protection .41 22.1 General .41 22.2 Motors and power transformers 42 22.3 Receptacles .43 23 Thermostats 44 24 Thermal Cutoffs 44 25 Attachment-Plug Receptacles 45 26 Lampholders .45 27 Switc
18、hes and Controls .46 27.1 General .46 27.2 Power output control circuits .49 28 Protective controls (Limiting controls) End Product Test Parameters 50 29 Filters .52 NOVEMBER 18, 2015 MICROWAVE COOKING APPLIANCES - UL 923 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTI
19、ON WITHOUT PERMISSION FROM UL 30 Spacings .52 31 Grounding 54 32 Secondary Circuits .54B 32.1 General .54B 32.2 Connections to frame 55 32.3 Separation of circuits 57 33 Transformers .57 34 Batteries and Battery Charging Circuits 57 35 Capacitors 58 36 Light Sources and Associated Components .59 PER
20、FORMANCE 37 General 59 38 Leakage Current Test 60 39 Microwave Radiation Emission Test .63 39.1 General .63 39.2 Instrumentation .63 39.3 Cavity load .63 39.4 Supply voltage 63 39.5 Microwave radiation emission measurement 63 40 Power Input Test .64 40.1 General .64 40.2 Supply voltage 64 40.3 Cavit
21、y load .64 40.4 Oven operation .64 41 Temperature Test .64 41.1 General .64 41.2 Temperature measurements 68 41.3 Installation 69 41.4 Supply voltage 79 41.5 Cavity load .79 41.6 Operating conditions .79 41.7 Motors used with solid-state controls 82 42 Surface Temperature Tests 84 42.1 General .84 4
22、2.2 Measurement of surfaces 85 42.3 Measurement of handles and knobs .88 42.4 Over-the-cooktop appliances .88 43 Insulation Resistance and Leakage Current Test as a Result of Moisture 91 44 Dielectric Voltage-Withstand Test 91 44.1 General .91 44.2 Primary circuits .92 44.3 Secondary circuits .94 45
23、 Door Assembly Tests 96 45.1 Door operation 96 45.2 All doors .96 45.3 Side-hinged doors .97 45.4 Bottom-hinged doors 97 45.5 Impact tests 97 46 Glass Control Panel Test 98 47 Metal Enclosure Impact Test 99 48 Interlock System Endurance Test 102 NOVEMBER 18, 2015 MICROWAVE COOKING APPLIANCES - UL 92
24、3 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 48.1 General 102 48.2 Appliance connections .102 48.3 Test equipment .102 48.4 Operating sequence .103 49 Interlock Monitor Circuit Test 104 50 Mechanical Endurance Test .105 51 Moisture Con
25、ditioning Test 105 52 Spill Test .106 53 Spill Test for Horizontally-Mounted Openings .106 54 Abnormal Operation Tests 107 54.1 General 107 54.2 Appliance connections .107 54.3 Appliance conguration 108 54.4 Test duration .108 54.5 Shorted thermostat test 109 55 Abnormal Operation Tests on Motors Us
26、ed With Solid-State Controls 110 56 Abnormal Operation Fire Isolation Test .111 57 Magnetically Operated Interlock Test .115 58 X-Radiation Test .115 58.1 General 115 58.2 X-radiation under servicing conditions .116 59 Temperature Control Tests .116 60 Temperature Probe Test 117 61 Motor Switch Test
27、 .117 62 Interlock Malfunction Test .118 63 Salt Spray Corrosion Test 118 64 Cavity Fire Containment Test .119 64A Forced Failure Fire Containment Tests 119 64A.1 General .119 64A.2 Potato re containment test .120 64A.3 Waveguide and stirrer re containment test .121 64A.4 Popcorn re containment test
28、 .121 64A.5 Thermally protected AC fan motor ignition test 121 64A.6 Nichrome wire ignition tests .122 65 Strength of Mounting Test .122A 66 Tests on Motors Exposed to Grease or Cooking Vapors 122B 66.1 General .122B 66.2 Grease conditioning 122C 66.3 Oven and humidity conditioning .122C MANUFACTURI
29、NG AND PRODUCTION-LINE TESTS 67 Dielectric Voltage-Withstand Test 123 68 Grounding-Continuity Test 125 RATING 69 Details .125 MARKINGS 70 General 126 NOVEMBER 18, 2015 MICROWAVE COOKING APPLIANCES - UL 923 4AUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERM
30、ISSION FROM UL 71 Visible After Installation .126 71.1 General 126 71.2 Combination microwave oven hood fans .128 72 Visible to the User During Use 129 73 Visible During Installation and Examination .129 74 Instruction Manuals 133 75 Important Safety Instructions 134 75.1 General 134 75.2 Over-the-c
31、ooktop microwave ovens .137 75.3 Microwave oven-vent hood fans .137 75.4 Self-cleaning appliances .137 76 Warning Markings and Instructions Concerning Microwave and X-Radiation Emission .137 77 Grounding Instructions .140 SELF-CLEANING OVENS GENERAL 78 Scope 141 CONSTRUCTION 79 Materials .142 79.1 O
32、ven coating .142 79.2 Smoke eliminators .142 79.3 Oven vent tubes and smoke diverters .142 80 Oven Door Latch/Interlock Assembly .142 81 Seals and Gaskets .143 PERFORMANCE 82 General 143 83 Temperature Test 144 83.1 General 144 83.2 Normal temperature .144 84 Latch-Solenoid Temperature Test 144 85 S
33、horted Thermostat Abnormal Test 145 86 Oven-Door Latch Endurance Test .145 87 Window Impact Tests 145 FIRE AND EXPLOSION 88 General 146 89 Test Electrodes 147 90 Test Samples .147 91 Installation of Test Sample 147 92 Fire and Explosion Test Within Oven .149 93 Emission of Carbon Monoxide .149 94 Ve
34、nt Gases and Vapors Test .150 95 Vertical Cool-Air-Mixing Duct Test .151 96 Self-Cleaning of Removable Companion Oven Panels Test .151 97 Elevated Interlock Operating Temperature Tests 152 NOVEMBER 18, 2015 MICROWAVE COOKING APPLIANCES - UL 923 4BUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER RE
35、PRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL MARKING 98 Details .152 NOVEMBER 18, 2015 MICROWAVE COOKING APPLIANCES - UL 923 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL NOVEMBER 18, 2015 MICROWAVE COOKING APPLIANCES - UL 923 6
36、No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL SUPPLEMENT SA - MICROWAVE COOKING APPLIANCES FOR MARINE USE GENERAL SA1 Scope SA1 CONSTRUCTION SA2 Mounting .SA1 SA3 Corrosion SA1 SA4 Supply Connections .SA1 SA4.1 Permanen
37、tly-connected appliances SA1 SA4.2 Cord-connected appliances SA2 SA5 Internal Wiring .SA2 SA6 Electrical Connections .SA2 PERFORMANCE SA7 General SA2 SA8 Vibration Test SA2 SA9 Shock Test .SA3 SA10 Salt Spray Corrosion Test SA3 MARKINGS SA11 Visible After Installation .SA4 SA12 Visible During Instal
38、lation and Examination SA4 SUPPLEMENT SB - MICROWAVE COOKING APPLIANCES EMPLOYING TUNGSTEN-HALOGEN LAMPS GENERAL SB1 Scope SB1 CONSTRUCTION SB2 Interlocks .SB1 SB3 Switches and Controls .SB2 PROTECTION AGAINST INJURY TO PERSONS SB4 Lamps SB2 SB5 Impact .SB3 SB6 Thermal Shock .SB3 SB6.1 Spillage SB3
39、SB6.2 Splashing SB3 MAY 1, 2013 MICROWAVE COOKING APPLIANCES - UL 923 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL PERFORMANCE SB7 Cavity load SB4 SB8 Ultraviolet Radiation Emission Test .SB4 SB9 Markings .SB5 MAY 1, 2013 MICROWAVE COOKI
40、NG APPLIANCES - UL 923 8UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover household and commercial microwave cooking appliances operated in the Industrial, Scientic and Medical (ISM) bands of 9
41、15 25 and 2450 50 MHz, for use in ordinary locations in accordance with the National Electrical Code, NFPA 70, and rated not more than 600 V. 1.2 These requirements also cover microwave cooking appliances intended for built-in installation, side-by-side mounting, stacking, wall mounting and installa
42、tion over ranges. 1.3 For the purpose of these requirements, commercial microwave cooking equipment is that usually found in commercial kitchens, restaurants, or other business establishments where food may be dispensed. Household microwave cooking equipment is that intended for household use. 1.4 T
43、hese requirements also cover the microwave cooking portion of a household electric range. The combination is to comply with the Standard for Household Electric Ranges, UL 858. 2 Glossary 2.1 For the purpose of this standard the following denitions apply. 2.2 AUTOMATICALLY CONTROLLED APPLIANCE An app
44、liance is considered to be automatically controlled under any one or more of the following conditions: a) If the repeated starting of the appliance, beyond one complete predetermined cycle of operation, is independent of any manual control; b) If, during any single predetermined cycle of operation,
45、the appliance is caused to stop and restart, or change operating modes one or more times; or c) If, upon energizing the appliance, the initial starting of a motor may be intentionally delayed beyond normal, conventional starting. 2.3 CAVITY That portion of the microwave cooking appliance in which fo
46、od may be heated, cooked, or dried. 2.4 CLASS 2 CIRCUIT An isolated secondary circuit involving a potential of not more than 42.4 V peak supplied by: a) An inherently-limited Class 2 transformer; b) A combination of an isolated transformer secondary winding and a xed impedance or regulating network
47、that together comply with the performance requirements for an inherently- limited Class 2 transformer; c) A dry-cell battery having output characteristics not greater than those of an inherently-limited Class 2 transformer; d) Any combination of (a), (b), and (c) that together comply with the perfor
48、mance requirements for an inherently-limited Class 2 transformer; or NOVEMBER 18, 2015 MICROWAVE COOKING APPLIANCES - UL 923 9UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL e) One or more combinations of a Class 2 transformer and an overcur
49、rent protective device that together comply with the performance requirements for a noninherently-limited Class 2 transformer. A circuit derived from a line-connected circuit by connecting impedance in series with the supply circuit as a means of limiting the voltage and current is not considered to be a Class 2 circuit. See Secondary Circuits, Section 32. 2.5 CONTROL, AUTOMATIC ACTION A control in which at least one aspect is non-manual. 2.6 CONTROL, AUXILIARY A device or assembly of devices
