1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 427 Refrigerating Units STANDARD FOR SAFETYUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FO
2、R FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Refrigerating Units, UL 427 Fifth Edition, Dated November 11, 2011 Summary of Topics This revision of ANSI/UL 427 consists of the Addition Of Alternate Method For Evaluating Protective Electronic Circuits An
3、d Controls Using Requirements Based On the Standard for Safety of Household and Similar Electrical Appliances, Part 1: General Requirements, UL 60335-1 and miscellaneous editorial corrections The new/revised requirements are substantially in accordance with Proposal(s) on this subject dated December
4、 30, 2016. 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 of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, mec
5、hanical 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 be liable for
6、 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 possibility of such d
7、amage. 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, liability, damage
8、, 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. FEBRUARY 10, 2017 UL 427 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION
9、 WITHOUT PERMISSION FROM UL FEBRUARY 10, 2017 UL 427 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL November 11, 2011 (Title Page Reprinted: February 10, 2017) 1 UL 427 Standard for Refrigerating Units First Edition
10、March, 1976 Second Edition December, 1989 Third Edition December, 1994 Fourth Edition December, 2006 Fifth Edition November 11, 2011 This ANSI/UL Standard for Safety consists of the Fifth Edition including revisions through February 10, 2017. The most recent designation of ANSI/UL 427 as an American
11、 National Standard (ANSI) occurred on February 10, 2017. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, and Title Page. The Department of Defense (DoD) has adopted UL 427 on April 9, 1992. The publication of revised pages or a new edition of this Standard will not i
12、nvalidate the DoD adoption. 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 https:/. ULs Standards for Safety are copyrighted b
13、y 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 2017 UNDERWRITERS LABORATORIES INC. ANSI/UL 427-2017UL COPYR
14、IGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL FEBRUARY 10, 2017 REFRIGERATING UNITS - UL 427 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 S
15、cope .6 2 General 6 2.1 Units of measurement .6 2.2 Terminology .6 2.3 Undated references .6 3 Glossary .6 CONSTRUCTION 4 General 8 5 Assembly 9 5.1 General .9 5.2 Electrical protection .9 6 Accessories .10 7 Enclosure .11 7.1 General 11 7.2 Openings .13 7.3 Doors and covers .19 7.4 Enclosures expos
16、ed to weather .20 8 Field-Supply Connections .22 8.1 Permanently connected equipment 22 8.2 Field wiring compartment .23 8.3 Cord-connected units 25 8.4 Grounding 27 9 Internal Wiring and Wiring Methods 28 9.1 General 28 9.2 High voltage circuits .29 9.3 Low voltage circuits 31 9.4 Wiring method 31
17、10 Separation of Circuits .35 11 Bonding for Grounding 36 ELECTRICAL COMPONENTS 12 Capacitors .38 13 Current-Carrying Parts 39 14 Electric Defrost Heaters .40 15 Fuseholders and Circuit Breakers .41 15.1 Fuseholders .41 15.2 Circuit breakers 42 16 Fuses and Supplementary Protectors .42 17 Insulating
18、 Material 43 18 Motors .43 19 Motor Overload Protection .46 19.1 General .46 19.2 Protection of single-phase nonhermetic motors 46 19.3 Protection of three-phase motors .49 19.4 Protection of hermetic refrigerant motor-compressors .49 FEBRUARY 10, 2017 REFRIGERATING UNITS - UL 427 3UL COPYRIGHTED MA
19、TERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 20 Switches and Controllers 50 21 Transformers .53 22 Valves and Solenoids .53 23 Outlet Boxes, Electrical Cable, Conduit and Tubing .54 24 Electromagnetic Interference Filters .54 25 Relays and Contactors 54 2
20、6 Optical Isolators and Semiconductor Devices 55 27 Terminal Blocks 55 28 Spacings 55 28.1 High-voltage circuits 55 28.2 Low-voltage circuits .57 29 Alternate Spacings Clearances and Creepage Distances 58 REFRIGERATION SYSTEM 30 General 59 30.1 Refrigerant 59 30.2 Pump-down capacity .59 30.3 Refrige
21、rant tubing and ttings 59 31 Refrigerant-Containing Parts .60 32 Pressure-Limiting Device 61 33 Pressure Relief .61 33.1 General .61 33.2 Relief valves .62 33.3 Fusible plugs or rupture members 62 34 Component Refrigeration Systems Integral to Other Appliances 62 PERFORMANCE 35 General 64 35.1 Tempe
22、rature measurements .64 35.2 Pressure measurements 65 35.3 Test voltage .66 36 Leakage Current Test Cord Connected Refrigerating Units .66 37 Input Test 66 38 Starting Test .67 39 Temperature and Pressure Test 67 40 Defrost Test 70 41 Dielectric Voltage-Withstand Test .71 42 Condenser Fan Motor Fail
23、ure Test 72 43 Condenser Water Failure Test 73 44 Overow Test 73 45 Rain Test 74 46 Strain Relief Test .77 47 Static Loading Test .77 48 Endurance Test Defrost Heater Control 78 49 Burnout Test .78 50 Overvoltage and Undervoltage Tests 79 51 Current Overload Test Bonding Conductors and Connections 8
24、0 52 Insulation Resistance Test .80 53 Limited Short-Circuit Test 80 53.1 General .80 53.2 Motor overload protective devices 82 FEBRUARY 10, 2017 REFRIGERATING UNITS - UL 427 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 53.3 Bonding cond
25、uctors and connections .83 53.4 Motor circuit conductors and connections .83 54 Maximum Continuous Current Test .83 55 Strength Tests 84 56 Fastener Retainer Test 86 57 Accelerated Aging Test Electric Heater 86 58 Reliability Test Heater Termination 87 59 Accelerated Aging Tests on Gaskets, Sealing
26、Compounds, and Adhesives 87 59.1 General .87 59.2 Sealing compound .88 59.3 Adhesives .88 60 Chromic Acid Dropping Test .89 61 Burnout Tests Electromagnetic Components .90 MANUFACTURING AND PRODUCTION TESTS 62 General 91 63 Production Line Dielectric Voltage-Withstand Tests .91 MARKING 64 General 93
27、 65 Refrigerant Markings 95 66 Permanently Connected Equipment .96 67 Cord Connected Units .99 68 Cautionary Markings 99 69 Accessory Markings 100 INSTRUCTIONS 70 Installation and Operating Instructions 101 SUPPLEMENT SA - REQUIREMENTS FOR REFRIGERATING UNITS EMPLOYING A FLAMMABLE REFRIGERANT IN THE
28、 REFRIGERATING SYSTEM SA1 Scope SA1 SA2 Glossary SA1 SA3 General SA2 SA4 Construction .SA2B SA4.1 General .SA2B SA4.2 Valves/ttings .SA2B SA4.3 Refrigerant Detection .SA2B SA5 Performance SA3 SA5.1 Leakage test .SA3 SA5.2 Ignition test .SA4 SA5.3 Temperature test SA5 SA6 Marking, Installation and Op
29、erating Instructions .SA5 SA6.1 Marking SA5 SA6.2 Installation and operating instructions SA6 FEBRUARY 10, 2017 REFRIGERATING UNITS - UL 427 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover r
30、efrigerating units intended for connection in accordance with the National Electrical Code, NFPA 70, to alternating-current (ac) circuits rated not greater than 600 volts. 1.2 This standard also covers component refrigeration systems (self-contained mechanical refrigeration systems), not already cov
31、ered by a UL standard, that heat, cool or dehumidify as integral (not stand-alone) components of appliances. 1.3 Refrigerating units covered by these requirements employ sealed, hermetic-type motor compressors, and air- or water-cooled condensers. 1.4 These requirements do not cover equipment intend
32、ed for comfort cooling. 2 General 2.1 Units of measurement 2.1.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information. 2.2 Terminology 2.2.1 The term “product” refers to any equipment covered by this standard unless specically noted
33、otherwise. 2.3 Undated references 2.3.1 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. 3 Glossary 3.1 For the purpose of this Standard the following denitions apply. 3.2 ACCE
34、SSORY An optional electrical device or component intended for installation in or connection to a product for the purpose of modifying or supplementing the functions of the product. It is intended for installation by the user or serviceman. 3.3 CAPILLARY TUBE Device made of tubing with an outer diame
35、ter of less than 3/16 inch (4.7 mm) and used to reduce the pressure of the refrigerant between the condenser and evaporator. It also regulates the refrigerant ow. 3.4 CIRCUITS, ELECTRICAL: a) High-Voltage A circuit involving a potential of not more than 600 volts and having circuit characteristics i
36、n excess of those of a low-voltage circuit. NOVEMBER 11, 2011 REFRIGERATING UNITS - UL 427 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL b) Low-Voltage A circuit involving a potential of not more than 30 volts ac, 42.4 volts peak or direc
37、t current (dc), and supplied by a primary battery, a standard Class 2 transformer, or a combination of a transformer and xed impedance which, as a unit, complies with all performance requirements for a Class 2 transformer. 3.5 COMPONENT A device or fabricated part of the appliance covered by the sco
38、pe of a safety standard dedicated to the purpose. When incorporated in an appliance, equipment otherwise typically eld installed (e.g. luminaire) is considered to be a component. Unless otherwise specied, materials that compose a device or fabricated part, such as thermoplastic or copper, are not co
39、nsidered components. 3.6 CONTROL, DEFROST CYCLE A control that is intended to regulate a defrost cycle. 3.7 CONTROL, OPERATING A control intended to start, regulate, or operate the appliance during normal operation. An example would be a thermostat or temperature controller. 3.8 CONTROL, PROTECTIVE
40、(SAFETY) A control intended to prevent the risk of electric shock, re, or injury to persons, typically during abnormal operation of the appliance. An example would be a pressure limiting control. 3.9 CONTROL, TEMPERATURE LIMITING A control that serves to prevent excessive temperature. 3.10 DESIGN PR
41、ESSURE The maximum allowable working pressure for which the refrigerating unit is designed. 3.11 PRESSURE VESSELS Any refrigerant-containing receptacle of a refrigerating system, other than evaporators (each separate section of which does not exceed 1/2 cubic foot (0.01 m 3 )o f refrigerant-containi
42、ng volume), evaporator coils, compressors, condenser coils, controls, headers and piping. 3.12 REFRIGERATING UNIT A complete refrigeration system consisting of a hermetic-motor compressor, condenser, evaporator, refrigerant control, electrical controls, wiring, and associated refrigerant containing
43、components including tubing; and may include a defrost system. These systems are primarily used to refrigerate cooling rooms and warehouses intended for the storage of food and other perishable products. 3.13 REFRIGERATION SYSTEM, COMPONENT A self-contained mechanical refrigeration system performing
44、 a heating, cooling or dehumidication function only as a component system of an appliance. It collectively consists of a hermetic-motor compressor, condenser, evaporator, refrigerant control, and associated refrigeration containing tubing and components. A defrost system may also be included. The ev
45、aluation of a component refrigeration system can only be determined in combination with the end product application. The reverse cycle heating function of a heat pump dryer is an example of a component refrigeration system. 3.14 ULTIMATE STRENGTH The highest stress level which a refrigerant-containi
46、ng component can tolerate without rupture. NOVEMBER 11, 2011 REFRIGERATING UNITS - UL 427 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONSTRUCTION 4 General 4.1 Ferrous metal parts used to support or retain electrical components in posi
47、tion shall be protected against corrosion by metallic or nonmetallic coatings, such as plating or painting. Exception: This requirement does not apply to parts, such as washers, screws, bolts, and similar parts, when corrosion of such unprotected parts would not affect compliance with the requiremen
48、ts in this standard. 4.2 Exposed unimpregnated asbestos material shall not be used in an air handling compartment. The unprotected edge of a gasket sandwiched between two parts is considered to be exposed. 4.3 A component shall: a) Comply with the safety standard covering that component; b) Be used
49、in accordance with its rating(s) established for the intended conditions of use; c) Be used within its established use limitations or conditions of acceptability; d) Comply with the applicable requirements of this end product standard; and e) Not contain mercury. Exception: A component of a product covered by this standard is not required to comply with a specic component requirement that: a) Involves a feature or characteristic not required in the application of the component in
