1、October 19, 20011SUBJECT 250AOUTLINE OF INVESTIGATIONFORHOUSEHOLD REFRIGERATORS AND FREEZERS FOR MARINE USEIssue Number: 2OCTOBER 19, 2001COPYRIGHT 2001 UNDERWRITERS LABORATORIES INC.OCTOBER 19, 2001SUBJECT 250A2No Text on This PageCONTENTSFOREWORD 4INTRODUCTION1 Scope .52 Terminology 5CONSTRUCTION3
2、 General 54 Protection Against Corrosion .55 Supply Connections .66 Wiring .77 Insulating Material .78 Electrical Connections .7PERFORMANCE9 Vibration Test 710 Shock Test 811 Salt-Spray Corrosion Test .8MARKING12 General .913 Installation Instructions .9OCTOBER 19, 2001 SUBJECT 250A 3FOREWORDA. This
3、 Outline of Investigation contains basic requirements for products covered by UnderwritersLaboratories Inc. (UL) under its Follow-Up Service for this category within the limitations given below andin the Scope section of this Outline of Investigation. They are subject to revision as further experien
4、ce andinvestigation may show is necessary or desirable.B. The observance of these requirements by a manufacturer is one of the conditions of the continuedcoverage of the manufacturers product.C. A product which complies with the text of this Outline of Investigation will not necessarily be judged to
5、comply with the Outline of Investigation if, when examined and tested, it is found to have other featureswhich impair the level of safety contemplated by these requirements.D. A product that contains features, characteristics, components, materials, or systems new or differentfrom those covered by t
6、he requirements in this Outline of Investigation, and that involves a risk of fire orof electric shock or injury to persons shall be evaluated using appropriate additional component andend-product requirements to maintain the level of safety as originally anticipated by the intent of thisOutline of
7、Investigation. A product whose features, characteristics, components, materials, or systemsconflict with specific requirements or provisions of this Outline of Investigation does not comply with thisOutline of Investigation. Revision of requirements shall be proposed and adopted in conformance with
8、themethods employed for development, revision, and implementation of this Outline of Investigation.E. UL, in performing its functions in accordance with its objectives, does not assume or undertake todischarge any responsibility of the manufacturer or any other party. The opinions and findings of UL
9、represent its professional judgement given with due consideration to the necessary limitations of practicaloperation and state of the art at the time the Outline of Investigation is processed. UL shall not beresponsible to anyone for the use of or reliance upon this Outline of Investigation by anyon
10、e. UL shall notincur any obligation or liability for damages, including consequential damages, arising out of or inconnection with the use, interpretation of, or reliance upon this Outline of Investigation.F. Many tests required by the Outline of Investigations of UL are inherently hazardous and ade
11、quatesafeguards for personnel and property shall be employed in conducting such tests.OCTOBER 19, 2001SUBJECT 250A4INTRODUCTION1 Scope1.1 These requirements cover household refrigerators and freezers for marine use intended forinstallation in enclosed accommodation spaces aboard a vessel. These requ
12、irements are in addition to therequirements specified in the Standard for Household Refrigerators and Freezers, UL 250.1.2 The refrigerators and freezers covered by the requirements in this outline are intended for installationin accordance with the requirements of the Standard for Pleasure and Comm
13、ercial Motorcraft, NFPA 302;the applicable requirements of the American Boat and Yacht Council, Inc.; and the United States CoastGuard Regulations as specified in 33 CFR 183 Subpart I Electrical Systems or 46 CFR Subchapter J Electrical Engineering, as applicable.2 Terminology2.1 Wherever the term r
14、efrigerator is employed in the following text, it is to be understood that therequirement also applies to a freezer.CONSTRUCTION3 General3.1 Provisions such as mounting holes, clamps, lugs, or equivalent means shall be provided forsecurement of the refrigerator to the vessel.4 Protection Against Cor
15、rosion4.1 All iron or steel parts of a refrigerator including bolts, nuts, screws, washers, and the like that arerelied upon for compliance with the requirements in this standard shall be provided with acorrosion-resistant finish by:a) A coating of cadmium (only in areas that are not expected to be
16、in contact with food),chromium, nickel, silver, or zinc applied by electroplating,b) Sheradizing,c) Hot-dip galvanizing,d) Enameling if the surface has been treated by bonderizing or the equivalent and by theapplication of zinc chromate primer prior to enameling, ore) Other types of paint or coating
17、s that provide equivalent resistance to corrosion asdetermined in the Salt-Spray Corrosion Test, Section 11.4.2 Cadmium and zinc chromate coatings shall not be used in:a) Food storage areas orb) Any area where indirect contact with food through condensation could occur.OCTOBER 19, 2001 SUBJECT 250A
18、54.3 The following materials are known to be corrosion resistant and need not be subjected to the saltspray corrosion test:a) Silver,b) Copper,c) Brass,d) Bronze,e) Copper-nickel,f) Aluminum alloys with a copper content of 0.4 percent or less,g) Wood, andh) Polymeric material.5 Supply Connections5.1
19、 Supply leads provided for connection to the branch circuit shall utilize only stranded copperconductors employing insulation:a) Of the flame retardant and moisture resistant type as specified in Article 310 of the NationalElectrical Code, ANSI/NFPA 70, orb) That has been investigated for marine use
20、, orc) That complies with the mechanical water absorption and applicable flame tests of theStandard for Thermoplastic-insulated Wires and Cables, UL 83.The conductors shall be at least No. 16 AWG (1.3 mm2), if separate, or No. 18 AWG (0.82 mm2)ifinamulticonductor sheath.OCTOBER 19, 2001SUBJECT 250A6
21、6 Wiring6.1 All internal wiring, other than motor or transformer windings, shall be Type 2 or Type 3 strandedcopper in accordance with Table 8-14.4 of the Fire Protection Standard for Pleasure and CommercialMotor Craft, NFPA 302.6.2 The insulation of internal and external wiring shall be:a) Rated fo
22、r the voltage and temperature to which they may be exposed,b) Moisture resistant and fire retardant, andc) Acceptable for the marine environment (resistant to oil, solvents, and salt water).7 Insulating Material7.1 Porcelain shall not be used as a base for mounting uninsulated live parts if the mate
23、rial is rigidlyfastened by machine screws or the like.8 Electrical Connections8.1 Aluminum or aluminum alloys shall not be used for terminal connections or for parts in direct contactwith copper conductors even if the aluminum alloy parts are plated.PERFORMANCE9 Vibration Test9.1 A refrigerator shal
24、l withstand 12 hours of vibration without:a) Leakage, cracking, displacement, breakage, or damage to components to an extent thatpresents a risk of fire, electric shock, or injury to persons;b) Reduction of electrical spacings to less than minimum acceptable values;c) Defeat of the ignition-protecte
25、d feature, if provided; andd) The door opening.Exception: A product marked in accordance with the requirement in 12.1 need not comply with thevibration test.9.2 A sample is to be mounted to the platform of a vibration machine in accordance with themanufacturers installation instructions and connecte
26、d to a source of rated supply.9.3 The sample is to be subjected to a variable-frequency vibration test along each of three rectilinearaxes (two perpendicular horizontal axes and a vertical axis) for 4 hours in each plane at a peak-to-peakamplitude (total platform displacement) of 0.020 0.002 inch (0
27、.51 0.06 mm). The frequency of vibrationis to be continuously varied, at a uniform rate, from 10 to 60 to 10 cycles per second every 4 minutes.OCTOBER 19, 2001 SUBJECT 250A 710 Shock Test10.1 A refrigerator shall withstand 1000 shock impacts without:a) Leakage, cracking, displacement, breakage, or d
28、amage to components to an extent thatpresents a risk of fire, electric shock, or injury to persons;b) Reduction of spacings to less than the minimum acceptable values;c) Defeat of the ignition protected feature, if provided; andd) The door opening.Exception: A product marked in accordance with the r
29、equirement in 12.1 need not comply with the ShockTest.10.2 The sample used for the Vibration Test, Section 9.1 is to be used for this test. The sample is to bemounted on the platform of a shock machine, as specified in 9.2, with its center of gravity as close aspossible to the geometric center of th
30、e machine platform, and connected to a source of rated powersupply.10.3 The sample is to be subjected to 1000 vertical shock impacts, each having a 10 g peak acceleration322 feet per second per second (98 m/s2) and a duration of 20 to 25 milliseconds as measured at thebase of the half sine shock env
31、elope.10.4 Following this test, the sample is to be subjected to the Temperature and Pressure Test, and theDielectric Voltage-Withstand Test, as stated in the Standard for Household Refrigerator and Freezers, UL250.11 Salt-Spray Corrosion Test11.1 Metal alloys and corrosion-resistant finishes not kn
32、own to be inherently resistant to corrosion are tobe tested for equivalence to the materials specified in 4.2. The metal alloys are to be subjected for 200hours to the tests described in the Standard Practice for Operating Salt Spray (Fog) Apparatus, ASTMB117. The results are acceptable if there is
33、no pitting, cracking, or other deterioration more severe thanthat resulting from a similar test on passivated AISI Type 304 stainless steel.OCTOBER 19, 2001SUBJECT 250A8MARKING12 General12.1 A refrigerator not shown to comply with the requirements of the Vibration Test, Section 9, or ShockTest, Sect
34、ion 10, shall be permanently marked, where readily visible after installation, with the followingor the equivalent: For Use Only on Vessels Over 20 Meters in Length.12.2 A refrigerator shall be permanently marked in an area that is visible prior to installation with thefollowing or equivalent wordin
35、g: Refer to Installation Instructions for Proper Installation.13 Installation Instructions13.1 The installation instructions shall have a separate section for marine installation that specificallydescribes the:a) Proper installation of the refrigerator to reduce the likelihood of tip over as a resul
36、t of pitchand roll,b) Proper ventilation needed,c) Ambient temperature range that should not be exceeded,d) Proper branch circuit protection, ande) Applicable installation code for the intended use.13.2 The instructions shall state that the refrigerator shall be installed in enclosed accommodation spacesonly and shall not be installed in areas requiring ignition protection.OCTOBER 19, 2001 SUBJECT 250A 9OCTOBER 19, 2001SUBJECT 250A10No Text on This Page
