1、A-39-/9 MIL-T- 27535A(ASG) 15 MAY 1964 Yu2erseiiing uaGa (see 6.4) MILITARY SPECIFICATION TRANSFORMER, POWER, ISOLATION: SERIES CIRCUIT, AIRPORT LIGHTING, GENERAL SPECIFICATION FOR This specificqtion has been approved by the Department of the Air Force and by the Bureau of Naval Weapons. 1. SCOPE 1.
2、1 This specification covers the general requirements for isolation, series circuit, power transformers for .airport lighting. 2. APPLICABU DOCUME;NTS 2.1 The following documents, of the issue in effect on date of invitation for bids or request for porposal, form a part of this specification to the e
3、xtent specified herein: SPECIFICATIONS Military MILC-l+921 MIGC-5136 MIL-1-7798 STANDARDS Militam MIGSTD-810 MIMTI)-831 Ba526 B33586 Cable, Power, Electrical, Airport Lighting, Cable, Power, Electrical, Polychloroprene Insulation Tape, Electrical, PressureSensitive Electronic and El.ctrica1 Equipmen
4、t and Associated General Requiremefits for Sheathed, Buna Compound Insulated Adhesive, Plastic Repair Parts, Preparation for Delivery of Identification Marking of US Miiitary Property Specifications and Standards, Order of Precedence Environmental Test Methods for Aerospace and Ground Teat Reports,
5、Preparation of Base, Airport Marker Ught Metals, Definition of Dissimilar for the Selection of Equipment THIS DOCUMENT CONTAINS (4 PAGES. - 1. - - -, 9 -% Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MILT-2753 5A( 4%) See Supplement 1 for list of
6、applicable MS Standards. (Copies of specifications, standards, drawings, and publications required by suppiiers in ponnection with specific procurement functions shaild be obtained from the procuring activity or as directed by the contracting officer.) specification to the exLent specified herein. i
7、ssue in effect on date of invitation for bids or request for proposal shall 2.2 Other publications.- The following doawaents form a part of this Unless othemise indicated, the apply: Federal Aviation Amncy L-823 Ir824 Plug and Receptacle, Cable Connectors Undergroinid Electric Cable for Airport Ligh
8、ting CircLiits (Copies of FAA documents may be obtained from the Federal Aviation Agency, Washington, D. C. 20553.) 3. REQU-TS 3.1 Qualification.- The transformer furnished under this specification shall be a product which has been subjected to and which has passed the quali- fication eests specifie
9、d herein, and which has been isted on or approved for listing on the applicable Qualified Products List. 3.2 Data.- Unless otherwise specified in the contract or order, no data (other than reports an$ drawings accompnying qualification samples) are required by this specification or any of the docume
10、nts referenced in section 2 (see 6.2). 3.3 Components.- The transformer shall consist of primary and secondary coils wound upon a core and inclbsed in a waterproof case with rubber connectors molded on the primary and secondary leads, standards for necessary commodities and services not specified he
11、rein shall be selected in accordance with MILSThi43. 3.4 Selection of Specifications and standards.- Specifications and 3.5 Materials. - 3.5.1 Funnu s-woof materials.- Materials that are nutrients for fungi shall not be used when it is practical to avoid them; when used they shall be treated with a
12、fungicidal agent. to resist corrosion due to fuels, aalt spray, or atmospheric conditions as may be encountered in storage or service. 2 3.5.2 Metals.- Metals shall be corrosion resistant or suitably treated Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IH
13、S-,-,-3.5.2.1 Dissimilar metals.- Unless suitably protected against electrolytic corrosion, dissimilar metals shall not be used in intimate contact with.each other. Dissimilar metals are defined in E33586. 3.5.3 Solder.; Lead-tin solder shall not be used. 3.6 Design and construction.- The design of
14、the transformer shall be in accordance with the applicable MS standard (see 6.2). 3.6.1 The transformer shall be designed to perform under environmental, mechanical, and electrical conditions specified herein for oontinuous service at ambient temperatures from -540 C to +65“ C, either on the surface
15、, buried directly in the ground, or submerged in water. 3.6.1.1 The transformer shallbe designed and constructed so that parts will not work loose in service. It shall be built to withstand the strains, jars, vibrations, and other conditions inCident to shipping, storage, installa- tion and-service.
16、 provided all requirements specifled herein and on the applicable MS standard are met, and the design is approved by the qualifying activity. with the requirements of the applicable MS standard, within a frequency range of 50 to 60 cycles per second. 3.6.1.3 Windings.- The windings shall be complete
17、ly insulated from each The exact shape and design of the transformer may be optional, 3.6.1.2 Rating.- The transformer shall be designed to operate in accordance other and the core. The transformer shall be designed to operate indefinitely on load, short-circuit, or open-circuit conditions in the se
18、condarywith rated current and frequency in the primary. capacity to allow for lamp aging and secondary contact losses. case so as to produce a competely watertight assembly. shall be less than 1/4 inch thick. assembly shall be eliminated or adequate provisions made so they will not cut the case if t
19、he transformer is dropped or handled roughly. The case shall be constructed so moisture accidentally getting into the leads or connectors cannot be conducted through the leads into the transformer. The case shall be molded from rubber or rubber-like compounds and may be molded .direbtly on the trans
20、- former or premolded and compound filled. Insofar as is practicable, internal air pockets shall be eliminated and the assembly shall be sufficiently rugged to withstand rough handling. The case shall be capable of withstanding exposure to sun, oil, gasoline, moisture, and acid and kaline soils. The
21、 case shall form a permanent watertight junction with the leads. The case and the trans- former shall be designed so that it can be installed in a MS2.4526 light base. It shall be possible to install the transformer in this base so that the leads are horisontalwithout excessive bending of the leads.
22、 No part of the trans- former and leads shall extend more than 8 inches above the bottom of the base. The transformer shall have sufficient 3.6.2. Case.-. ,The transformer shall be enclosed in a permanently sealed No portion of the case Sharp corners and edges of the core and coil 3 Provided by IHSN
23、ot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IL-T-27535A( ASG) 3.6.3 Cables.- The transformer shall be provided with a two-conductor securely fastened to the transformer in such a manner that carrying by the cables will not loosen the electrical connections or da
24、mage the water seal. connector shall be molded on the outer end of each lead, as specified on the applicable MS standard. .secondary cable and two single-conductor primary cables. The cables shall be A Cable lengths shall be 3*6.3.1 Primary cables,- Primary cables shall be single conductor, 5,00OV,
25、No. 8 AWG stranded cable conforming to MIL-C-4921 or FAA-I.-824, type B. shall be marked H1 and H2. figure 6a of:FAA-L823 and the H2 cable shall connect to the receptacle shown on figure 6b of 2iLk-L-623. Secondary cable - The secondary cable shall be 600V, two-conductor , No. 12 AWG flexible cord c
26、onforming to MLLC-5136 or FAA-L-824, type A and shall terminate in a 600V, two-pole receptacle in accordance with FAA-L-823, as speci- fied on the applicable MS standard. Each conductor shall have not less than 37 strands. The receptacle shall be so wired that the large contact: will connect to the
27、XI lead of the transformer secondary and the smaller contact will connect to the X2 lead. The cables The H1 cable shall connect to the plug shown on 3.6.3.2 3.6.4 Caps. the high voltage lead in water alongside a transformer and by suspending it in air. Zero and meximum readings of the test instrumen
28、t shall be periodically Dc test Minimum insulation volt age resistance in megohms TABLE I. Insulation resistance 750 2,000 300 750 Secondary Primary 4.7.4 Insulation resistance (individual tests).- Each transformer shall be subjected to one complete cycle of the test specified in 4.7.3, by the quali
29、fying activity, the following modifications may be made in the test specified in 4.7.3. When approved 4.7.4.1 The heating cycle specified in 4.7.3.2 may be conducted by heating the transformers in an oven, or by short circuiting either the primary or secondary coil and circulating slightly more than
30、 rated current through the other coil. atures in the coils, case, and leads of a transformer than the 5-hour open- circuit conditions, and the transformers shall be heated for not less than 2 hours. 8 The heating cycle, however, shall produce equivalent or greater temper- Provided by IHSNot for Resa
31、leNo reproduction or networking permitted without license from IHS-,-,-MIL-T-27535A( ASG) 4.7.4.2 Primary conn:eictors of several transformers may be plugged directly hgether and the transformers heated, soaked, and tested as a group, as for one transformer. primary coils of the group shall be not l
32、ess than that specified for a single transformer, are completed. not subjected to the impact test shall be determined by the resistance method and shall not exceed 55“ C when the transformer is operated under any of the following conditions with the rated current in the primary: The minimum acceptan
33、ce insulation resistance for the combined No connector in the group shall be unplugged until after the tests 4.7.5 Temperature rise.- The temperature rise of the transformer windings (a) Rated load (b) Short Gircuit (c) Open circuit 4.7.6 Destructive examination.- One transformer shall be cut open a
34、nd examined internally and externally to determine compliance with all requirements of this specification. tests conducted in accordance with the specified procedures of MIL-STD-810. 4.7.7.1 High temperature.- The transformer shall be subjected to high temperature in accordance with Method 501, Proc
35、edure I, except the temperature shall be 65“ C. 4.7.7 Environmental.- The transformer shall be subjected to the following 4.7.7.2 Low temperature.-: The transformer shall be subjected to low temperature in accordance with Method 502, Procedure I. determine that preservation, packaging, packing and m
36、arking are in accordance with section 5. (See 5.1;) 5. PREPARATION FOR DELIVERY 4.7.8 Inspection for delivers.- The transformers shall be inspected to 5.1 Preservation, packaging, rn ckina, and markinec.- Transformers shall be preserved and packaged in accordance with level A or C of MTGE-17555, as
37、specified (see 6.2). They shall be packed in accordance with level A, B, or G, as specified (see 6.2), and marked in acooedance with MILE-17555. 6. NOTES 6.1 Intended use.- The transformers are intended for use in both permanbnt and advance airport Lighting series circuit installation. 6.2 Ordering
38、data.- Procurement documents should specify: (a) (b) (c) (d) Title, number, and date of this specification. MS part number (see 3.6.). Levels of preservation, packaging, and packing required (see 5.1). Reports or drawings, if other than 4.4.2 (see 3.2). 9 Provided by IHSNot for ResaleNo reproduction
39、 or networking permitted without license from IHS-,-,-MIL-T-27535A (AS) 6.3 Qualification.- With respect to products requiring qualification, awards will be made only for such products as have, prior to the time set for opening of bids, been tested and approved for inclusion in the applicable Qualif
40、ied Products List whether or not such products have actually been so Usted by that date, The attention of suppliers is called to this requirement and manufscturers are urged to arrange to have the products that they propose to offer to the Federal Government tested for qualification in order that th
41、ey may be eligible to be awardedcontracts or orders for the products covered by this specification. The activity responsible for the qualified products list is the Systems Enginming Group, Wright-Patterson Air Force Base, Ohio 45433, ATTN: obtained from that activity. dated 23 May 1963, MILT-4949A(A
42、SGy dated 28 May 1958, MfLT-k950A(ASG) dated 7 July. 1958, and MIL-T-7641B(ASG) dated 28 September 1955. SEHCC, and information pertaining to qualification of products may be 6.4 Suuerseding data.- This s ecification superseds MILT-27535(USAF) Custodians: Air Force - (il) Navy - Weps Preparing activ
43、it : Air Force - (lly Rev5ewer activity: Air Force - (il), (85) Navy - Weps Review/user information is current as of the date of this document. coordination of changes to this document, draft circulation should be based on the information in the current Federal Supply Classification Listing of DoD standardisation documents. For future 10 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
