1、AMSC N/A FSC 5950 INCH-POUND MIL-PRF-27/348C 13 July 2012 SUPERSEDING MIL-PRF-27/348B 17 January 1986 PERFORMANCE SPECIFICATION SHEET TRANSFORMERS, POWER, 270 VOLTAMPERES, 3-PHASE This specification is approved for use by all Departments and agencies of the Department of Defense. The complete requir
2、ements for procuring the transformer described herein shall consist of this document and the latest issue of specification MIL-PRF-27. (For dash numbers 01 through 06) Primary (For dash nos. 01 thru 06) WYE, 115 V to Com 1,2,3 line 4 Com WYE, 200 V L-L 1,2,3 (For dash numbers 07 through 18) SECONDAR
3、Y WYE, L Com Connect 6-8-10, Load 5-6, 7-6, 9-6 DELTA, L-L Connect 6-7, 8-9 5-10, Load 5,7,9 WYE, L-L Connect 6-10, 8-10, Load 5,7,9 PRIMARY (For dash nos. 07 thru 12) Delta, 115 V L-L 1,2,3 PRIMARY (For dash nos. 13 thru 18) Delta, 200 V L-L 1,2,3 CIRCUIT DIAGRAMS FIGURE 1. Dimensions and configura
4、tions. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-27/348C 2 NOTES: 1. Dimensions are in inches. 2. Metric equivalents are given for general information only. 3. Unless otherwise specified, tolerance is .04 (1.0 mm). 4. Marking shall be o
5、n top and side of case. 5. Terminal 4 is missing for dash nos. 07 thru 18. FIGURE 1. Dimensions and configurations - Continued. Inches mm .010 0.25 .02 0.5 .090 2.29 .1640 4.165 .20 .25 5.1 6.4 .28 7.1 .40 10.2 .82 20.8 1.22 31.0 1.99 50.6 2.50 63.5 3.04 77.2 3.15 80.0 3.69 93.7 Provided by IHSNot f
6、or ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-27/348C 3 REQUIREMENTS: (When numbers in parentheses, i.e., (1-2) are used, they indicate the winding and the extreme terminals of the winding.) Electrical ratings: Primary voltage at 400 20 Hz Wye connected (dash
7、numbers 01 through 06). (1-4): 115 V ac. (2-4): 115 V ac. (3-4): 115 V ac. (1-2): 200 V ac. (1-3): 200 V ac. (2-3): 200 V ac. Delta connected (dash numbers 07 through 12) (1-2): 115 V ac. (1-3): 115 V ac. (2-3): 115 V ac. Delta connected (dash numbers 13 through 18) (1-2): 200 V ac. (1-3): 200 V ac.
8、 (2-3): 200 V ac. Secondary voltage: See table I. Secondary current: See table I. Working voltage: 535 volts peak, maximum. Design and construction: Dimensions and configuration: See figure 1. Duty cycle. Continuous. Case: Epoxy fiberglass. Terminals: Solderable turret type. Height: 0.28 .040 inch (
9、7.11 1.02mm). Diameter: 0.090 .010 inch (2.29 0.25mm). Weight: 2.8 pounds, maximum. Operating temperature range. -55 to +130C. Altitude: 70,000 feet. Terminal strength: MIL-STD-202, method 211, test condition A, 5 pounds. Dielectric withstanding voltage (Secondary connected wye): At atmospheric pres
10、sure (each winding): 1500 volts rms. At barometric pressure (each winding): 670 volts rms Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-27/348C 4 Electrical characteristics: Rated load: With rated voltage across the primary at 400 Hz, the v
11、oltage across each winding of the secondary, wye connected, shall be as specified in Table I within 5 percent at the current specified in TableI. Regulation: Shall not exceed 10 percent when computed as follows: 100)()()(xloadratedVoltageloadratedVoltageloadnoVoltage TABLE I. Electrical ratings - se
12、condary. Dash numbers M27/348- Wye (L-Com) 4 wire 1/ Delta (L-L) 3 wire 2/ (each winding) Wye (L-Com) 4 wire 3/ (each winding) DC resistance 1/ Wye (L-Com) (each winding) Load current Load current 01, 07, 13 02, 08, 14 03, 09, 15 04, 10, 16 05, 11, 17 06, 12, 18 Volts rms 5 15 20 28 48 115 Amperes r
13、ms 7.50 6.00 4.50 3.22 1.88 0.79 Volts rms 20.8 26.0 34.6 48.5 83.1 200 Amperes rms 4.33 3.47 2.60 1.86 1.09 0.45 Ohms 25% .0142 .0232 .0383 .0843 .231 1.41 1/ Wye, line to common, connect (6-8-10), load (5-6), (7-6), and (9-6). 2/ Delta, line to line, connect (6-7), (8-9), and (5-10), load (5-7-9).
14、 3/ Wye, line to line, connect (6-10), (8-10), load (5-7-9). Efficiency (at rate load): Shall be a minimum of 90 percent when computed as follows with secondary connected wye, L-com (Secondary voltage) (Secondary current) X 100 (Primary phase voltage) (Primary phase current) DC resistance (dash numb
15、ers 01 through 06): Primary: (1-4): 1.2 ohms 25 percent. (2-4): 1.2 ohms 25 percent. (3-4): 1.2 ohms 25 percent. DC resistance (dash numbers 07 through 12): Primary: (1-2): 0.80 ohms 25 percent. (2-3): 0.80 ohms 25 percent. (3-1): 0.80 ohms 25 percent. Provided by IHSNot for ResaleNo reproduction or
16、 networking permitted without license from IHS-,-,-MIL-PRF-27/348C 5 DC resistance (dash numbers 13 through 18): Primary: (1-2): 2.18 ohms 25 percent. (2-3): 2.18 ohms 25 percent. (3-1): 2.18 ohms 25 percent. Secondary: See table I. Temperature rise: 50C with rated voltage and current at 400 Hz, the
17、 secondary shall be wye connected at an ambient temperature of 80C. Shock (specified pulse): MIL-STD-202, method 213. Marking location: See figure 1. Part or Identifying Number (PIN): M27/348-(dash number from table I). VERIFICATION: Extent of qualification: Qualification testing and approval to M27
18、/344-07 and M27/349-18 shall be sufficient to grant qualification approval to MIL-PRF-27/344 through MIL-PRF-27/349 inclusive, all parts. Qualification testing and approval to M27/348-18 shall be sufficient to grant qualification approval to M27/348-01 through M27/348-18. Changes from previous issue
19、. The margins of this specification are marked with vertical lines to indicate where changes from the previous issue were made. This was done as a convenience only and the Government assumes no liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to eva
20、luate the requirements of this document based on the entire content irrespective of the marginal notations and relationship to the last previous issue. Referenced documents. In addition to MIL-PRF-27, this document references the following: MIL-PRF-27/344 MIL-PRF-27/349 MIL-STD-202 Custodians: Prepa
21、ring activity: Army - CR DLA - CC Navy - EC Air force 85 DLA - CC Review activities: (Project 5950-2009-098) Army CR4, MI Navy - AS, MC, OS Air Force - 19, 99 NOTE: The activities listed above were interested in this document as of the date of this document. Since organizations and responsibilities can change, you should verify the currency of the information above using the ASSIST Online database at https:/assist.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
