1、October 13, 20041SUBJECT 2446OUTLINE OF INVESTIGATIONFORUNITARY BOILER ROOM SYSTEMSIssue Number 1October 13, 2004Summary of TopicsThis is the first issue of the Outline of Investigation for Unitary BoilerRoom Systems.The UL Foreword is no longer located within the UL Standard. For informationconcern
2、ing the use and application of the requirements contained in thisStandard, the current version of the UL Foreword is located onULStandardsInfoNet at: http:/ 2004 UNDERWRITERS LABORATORIES INC.OCTOBER 13, 2004SUBJECT 24462No Text on This PageCONTENTSINTRODUCTION1 Scope .52 Components 53 Units of Meas
3、urement .64 Undated References 65 Glossary .6STRUCTURE CONSTRUCTION6 General 67 Outdoor Structures 78 Structure Base 89 Walls 810 Roof Panels .811 Doors 912 Ventilation and Combustion Air 9INSTALLED EQUIPMENT13 Equipment Location .1014 Working Space .1015 Structure Electrical Circuits 1116 Panelboar
4、ds .1117 Lighting Circuits 1218 Attachment-Plug Receptacles 1319 HVAC Circuits 1319.1 General .1319.2 Room type air conditioners 1419.3 Structure type air conditioning systems .1420 Fixed Electric Heating Equipment .1521 Emergency Lighting/Exit Signage .1522 Intrusion Alarms 1623 Smoke/Fire Detectio
5、n/Protection 1624 Piping, Tubing And Fittings 16ELECTRICAL ASSEMBLY25 General 1826 Spacings 1827 Field Wiring 1928 Grounding .2029 Internal Wiring 2130 Cable Trays 2331 Intermediate Metal Conduit (IMC) and Rigid Metal Conduit 2432 Electrical Metallic Tubing (EMT) 2533 Flexible Metal Conduit .2534 Li
6、quid Tight Flexible Metal Conduit 2635 Boxes and Fittings 2636 Transformer Protection 28OCTOBER 13, 2004 SUBJECT 2446 337 Main Disconnect 2938 Service Equipment Services Rated 600 V or Less 2939 Motors And Motor Overload Protection 3140 Control Cabinets 3241 Securement Of Components .3942 Fuses and
7、Fuse Holders .40PERFORMANCE43 General 4044 Test Voltage .4045 Power Input Test .4146 Rain Test 4147 Wind Test 4448 Dielectric Voltage-Withstand Test .46MANUFACTURING AND PRODUCTION TESTS49 General 47MARKING50 General 47INSTRUCTIONS51 General 50OCTOBER 13, 2004SUBJECT 24464INTRODUCTION1 Scope1.1 Thes
8、e requirements apply to unitary boiler room systems intended for general use rated 600 volts orless. The structure of the system is not intended for occupancy by personnel for other than operating thecontrolled equipment or performing equipment maintenance.1.2 These products consist of an overall en
9、closure, with related lighting and control power circuits, andelectrical equipment together with the associated piping and wiring between equipment.1.3 The systems as covered by these requirements are intended for installation in accordance with theStandards for Installation of Oil-Burning Equipment
10、, NFPA 31, and other codes such as the National FuelGas Code, NFPA 54, the National Electrical Code, NFPA 70, International Mechanical Code (ICC), andthe Uniform Mechanical Code (IAPMO).1.4 Equipment covered by these requirements may be operated without a qualified attendantcontinuously on duty.2 Co
11、mponents2.1 Except as indicated in 2.2, a component of a product covered by this Outline of Investigation shallcomply with the requirements for that component.2.2 A component need not comply with a specific requirement that:a) Involves a feature or characteristic not needed in the application of the
12、 component in theproduct covered by this Outline, orb) Is superseded by a requirement in this Outline.2.3 A component shall be used in accordance with its rating established for the intended conditions ofuse.2.4 Specific components are incomplete in construction features or restricted in performance
13、 capabilities.Such components are intended for use only under limited conditions, such as certain temperatures notexceeding specified limits, and shall be used only under those specific conditions.OCTOBER 13, 2004 SUBJECT 2446 53 Units of Measurement3.1 Values stated without parentheses are the requ
14、irement. Values in parentheses are explanatory orapproximate information.3.2 Unless indicated otherwise, all voltage and current values mentioned in this standard are rms.4 Undated References4.1 Any undated reference to a code or standard appearing in the requirements of this Outline shall deinterpr
15、eted as referring to the latest edition of that code or standard.5 Glossary5.1 For the purpose of this Outline the following definitions apply.5.2 COMBUSTIBLE MATERIAL Material made of or surfaced with wood, compressed paper, plantfibers, plastics, or other material that can ignite and burn, whether
16、 flameproofed or not, or whetherplastered or unplastered.5.3 STRUCTURE A General cargo container that is totally enclosed and weather-resistant, having arigid roof, rigid side walls, rigid end wall and a floor, having at least one of its end walls equipped withdoors. Identification marking Type Code
17、 “GO”.STRUCTURE CONSTRUCTION6 General6.1 An ISO Series 1 General Purpose Container covered by International Standards ISO 668, Parts 1 to5 of ISO 1496, ISO 8323, marked in accordance with ANSI/ISO 6346, sometimes referred to as“Intermodal freight container” meets the intent of these requirements.6.2
18、 Structures shall be made and finished with the degree of uniformity and grade of workmanshippracticable in a well equipped factory.6.3 Completed structures shall be supplied with all necessary component parts, including provisions forlifting, if required.6.4 Structures shall be fully assembled, inc
19、luding all walls, floors and roofs.6.5 Complete drawings shall be provided that show sidewall, endwall, cross sections, base details andrecommended anchoring methods.6.6 Unless the structure is of a material that will resist corrosion, both inside and outside surfaces shallbe protected by painting,
20、galvanizing, or plating, or a combination thereof.OCTOBER 13, 2004SUBJECT 244666.7 A part of the structure, such as a door or cover, that, when opened, provides access to exposed liveelectrical parts, shall be provided with a means, such as latches, locks, interlocks, or captive fasteners,for firmly
21、 securing it in place. Such fasteners shall be so located or used in multiple so as to hold the dooror cover closed over its entire length. A hinged cover more than 48 inches (1219 mm) long on the hingedside shall have at least a two point latch operated by a single knob or handle, or shall have at
22、least twocaptive fasteners.6.8 Cover plates intended to be removed for inspection purposes shall not exceed 12 ft2(1.11 m2) in areaor 60 lb (27.2 kg) in weight unless equipped with lifting means or hinges.7 Outdoor Structures7.1 A structure intended for outdoor installation shall comply with 7.2 7.7
23、.7.2 Hinges and other attachments shall be resistant to corrosion. Metals shall not be used incombinations that result in galvanic action that adversely affects any part of the device.7.3 Copper, bronze, brass containing not less than 80 percent copper or stainless steel may be usedwithout additiona
24、l protection against corrosion. Aluminum (sheet, extrusion, or cast), die-cast zinc, or othermetal shall be of a grade of alloy known to be corrosion resistant.7.4 Outdoor sheet steel surfaces shall be protected against corrosion by one of the following coatings:a) Hot-dipped mill galvanizing confor
25、ming with the coating Designation G90 of ASTM A653,Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated(Galvannealed) by the Hot-Dip Process, with not less than 40 percent of the zinc on any side,based on the minimum single spot test requirement in the ASTM A653
26、 designation.b) A zinc coating, other than that provided on hot-dipped mill galvanized sheet steel, uniformlyapplied to an average thickness of not less than 0.00061 inches (0.015 mm) on each surfacewith a minimum thickness of 0.00054 inches (0.014 mm). An annealed coating shall complywith 7.5.c) A
27、zinc coating conforming with (1) or (2) below and with one coat of an organic finish ofepoxy or alkyd-resin type or other outdoor paint applied on each surface after the metal hasbeen formed.1) Hot-dipped mill galvanized sheet steel conforming with the coating Designation G60or A60 of ASTM A653, wit
28、h not less than 40 percent of the zinc on any side, based onthe minimum single spot test requirement in this ASTM designation.2) A zinc coating, other than that provided on hot-dipped mill galvanized sheet steel,uniformly applied to an average thickness of not less than 0.00041 inches (0.010 mm)on e
29、ach surface with a minimum thickness of 0.00034 inches (0.009 mm).d) A cadmium coating not less than 0.0010 inches (0.025 mm) thick on both surfaces.e) A cadmium coating not less than 0.00075 inches (0.019 mm) thick on both surfaces, withtwo coats of outdoor paint on both surfaces. The paint shall b
30、e as described in (c) above.OCTOBER 13, 2004 SUBJECT 2446 77.5 Sheet steel with an annealed coating where the steel is bent or similarly formed or extruded or rolledat edge of holes after annealing shall be additionally painted in the affected area if the process damagesthe zinc coating. Simple shea
31、red or cut edges and punched holes are not required to be additionallyprotected.7.6 If a structure has any opening for passage of a wire or bus bar to other outdoor equipment, or to awireway, auxiliary gutter or busway, a gasket or other means shall be provided that will keep water fromentering at s
32、uch opening.7.7 All joints and seams should be welded or sealed with an adhesive caulking material suitable foroutdoor use.8 Structure Base8.1 The structure base shall be of rigidly braced structural members. The base shall be suitable forinstallation on a foundation or on piers. Instructions for in
33、stallation provided with the structure shallindicate the recommended foundation or pier location, if applicable.8.2 All materials used in the base construction shall be provided with corrosion protection.8.3 The floor shall have sufficient strength to withstand the loading imposed by all installed e
34、quipment andany equipment normally used during maintenance of the installed equipment.8.4 The floor finish shall be slip-resistant, either by use of slip-resistant coatings or surface configuration.Removable floor coverings (such as rubber mats) may be supplied, but shall not serve as the sole means
35、for slip-resistance.9 Walls9.1 For outdoor structures, if a wall is constructed of multiple panels, the panels shall overlap or interlockto preclude the entrance of water, as described herein.9.2 Thermal insulation may be provided in the walls.10 Roof Panels10.1 For outdoor structures, roof panels s
36、hall overlap or interlock to preclude the entrance of water asdescribed herein.10.2 For outdoor structures, where roof panels meet at the ridge line, a ridge cap shall be provided. Theridge cap shall overlap or interlock with the roof panels to preclude the entrance of water as describedherein.OCTOB
37、ER 13, 2004SUBJECT 2446811 Doors11.1 Where access to the structure interior is required for operation or maintenance, a minimum of onedoor shall be provided.11.2 Doors shall have exterior hardware of corrosion resistant materials, or provided with plating toprevent corrosion.11.3 Personnel doors sha
38、ll be provided with automatic closing means. Where a personnel door locksautomatically upon closing, it shall be possible to open the door from inside the structure without the useof a key or tool.12 Ventilation and Combustion Air12.1 Structures shall have sufficient ventilation in the form of louve
39、rs or vents to provide cooling. Louversor vents must be provided with hoods, or otherwise designed to preclude the entrance of water. Hoodsmay additionally provide sound attenuation. Louvers provided for ventilation may be gravity actuated ormotorized. The amount of square footage for air entering t
40、he structure is to be computed as detailed in12.2 12.4.12.2 Structures shall have two permanent openings, one commencing within 12 inches (30 cm) of the top,and one coming within 12 inches (30 cm) of the bottom of the enclosure. Each opening shall have aminimum free area of 1 square inch per 4,000 B
41、tu/h (5.5 sq. cm per kW) of total input rating of allequipment in the enclosure.12.3 Structures may have one permanent opening commencing within 12 inches (30 cm) of the top of theenclosure having a minimum free area of 1 square inch per 3,000 Btu/h (7.3 sq. cm. per kW) of total inputrating of all e
42、quipment in the enclosure.12.4 In calculating the free area in 12.2 and 12.3, consideration shall be given to the blocking effect oflouvers, grills, or screens protecting openings. Screens used shall not be smaller than 1/4 inch (6.3 mm)mesh. When the free area through a design of louver or grill is
43、 known, it shall be used in calculating thesize opening required to provide the free area specified. If the design and free area are not known, it shallbe assumed that metal louvers and grills have 60 75 percent free area. Adjustable louvers and grillsshall be fixed in the open position or interlock
44、ed with the equipment so that they are opened automaticallyduring equipment operation.OCTOBER 13, 2004 SUBJECT 2446 9INSTALLED EQUIPMENT13 Equipment Location13.1 Equipment shall be mounted to the floor, wall, or ceiling.13.2 Equipment with ventilating openings shall be mounted so that the ventilatio
45、n openings are notobstructed.13.3 Wall- or ceiling-mounted equipment shall be mounted so that operating mechanisms, push buttons,selector switches, and the like are located no more than 6-1/2 feet (2.0 m) from the floor or work platform.13.4 When provided, work platforms shall be provided with perma
46、nent ladders or stairs.13.5 Equipment mounted above areas likely to be used by personnel operating the equipment shall bemounted more than 6-1/2 feet (2.0 m) above the floor or work platform and shall have no operatingmechanism or switches for operator use. Where the electrical equipment exceeds 6-1
47、/2 feet (2.0 m), theminimum headroom shall not be less than the height of the equipment.14 Working Space14.1 Equipment shall be installed within the structure so as to permit a minimum of 90 degree opening ofall doors or hinged panels.14.2 The minimum headroom around installed equipment shall be 6-1
48、/2 feet (2.0 m), measured from thefloor or working platform.14.3 Illumination shall be provided for all workspaces. The interior structure lights may be relied upon tomeet this requirement, unless obstructed when the equipment door or cover is opened. Lighting circuitsshall comply with Section 17.14
49、.4 The width of workspace in front of equipment shall be the width of the equipment or 30 inches (760mm), whichever is greater. The height of workspace in front of equipment operating at 600 V or less shallextend 6-1/2 ft (2.0 m) above the floor or platform. The depth of the workspace shall comply with Table110.26(A)(1) of the National Electrical Code, ANSI/NFPA 70 and is to be measured from the enclosureopening with the door or cover open. Where equipment is located on both sides of an aisle, the workspacerequired by Condition 3
