Downloaded from https://www.everyspec.com MIL-S'l'J)..T04A 10000ICE .1 1 nanD! 1968 MILl'l'ABY S'l'AIDARD BLECDIC POWER, AIRCRAPl', ClWlAC'1'BBIS'l'ICS AID U'lILlZA'l'IOR OF '!'bie actice should be t11e4 in front at Nll1ta.ry Stan4ard MIL-S'l'D-T04A, dated 9 .AQswlt 1966. !l'O ALL AC'l'IVI'l'IES: 1. Malte the tollowing pen and ink chan ... : (a) pqe 1, paragraph 1.3: Delete, ad substitute: "1.3 Baeis tor characteristics. 'lbe characteristics aDd limits delineated and epeci fied 1n this standard are baaed on the utilization restrictions and requirements atated in aection 6 ad the notes and ..

sumptions stated in section T ot this standard." (b) Paae 1, paragraph 3.3.2, last 11ne; Delete "limite" and substitute "level", (c) Page 5. paragraph 5.1.3.5: Delete, ad substitute: "5.1.3.5 Wave torm.- 'lbe voltage wave torm aha.ll be within the f'ollowing limits: (a) Deviation tactor: The wave torm shall not deviate f'rom corresponClina points of' the tundamental by more than 5 percent ot the peak value ot the fundamental. (b) '.rotal harmonic content: 8 percent of' the tundamental (J'DIS) when measured with a Clisto%'tion meter as distortion of'the tundamental frequency. (c) Individual harmonic content: 5 percent ot the f'uDclamontal (rms) when measured with a harmonic analyzer.

Crest tactor: 1.~1 +0.15 (see 1.6.8). (Note: Deviation tactor computed trom the aatual creat tactor ~ exceed the deviation f'actor at the peak ot the wave torm.)" " "(b) Emergency power sources - '!'be frequency shall be maintained at 400 :t.40 cps with the voltage within the limits of'table I. Below 360 cps, the t're quency/voltage (F/V) ratio shall not tall below 3.0 (F/V)." (d) Page 6. parasraph 5.1.5: Revise item (b) to read as tollows: (e) Page 1. paragraph 5.2.3. last two linee: Delete last sentence. (t) Page 9. paragraph 6.8.1,1, aecond and tbird lines: Dele+e !!Iecona aentence. Ipse - MIse ./

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Downloaded from https://www.everyspec.com HIL-STD-704A Notice -1 7 February 1968 (g) Peae ~2. parearaph 1.6.4: De~ete. and sUbstitute: "7.6.t. E1ectric-system characteristics. Characteriatj,cs covered in this standard are based on the electric paver source beins: (1) Constant speed drives (.peed control in h7Q,raulic or mechanical torque converter). (a) AC or dc generators 4rlven by: (2) Constant speed turbines (speed control on air or gas turbine). (3) Barrow range, variable speed tran8misaions (turboprops, helicopter rotors. etc.). (b) DC generators driven by: (~) Wide range, variab~e .peed transm1saioQs (piston engines).

(c) Inverters (d) Transformer-rectifiers (e) Batteries Components of the power system are to meet the reqUirements ot their detail specifica tions, and the system is to provide the characteristic8 specified in this stanl2ar4." (h) Page ~3. parasraph 1.6.7: Change "85 percent" to "80 percent". (i) Page 15. table II, under column tit~ed "LARDING": De~ete: Substitute: "2~ ... 28.5" t123.5 _ 28.5" "20 - 28.5" "22.5 - 28.5" "~9 .. 28.5" "21.5 - 28.5" (j) Pages ~7. ~8, and ~9. figures ~, 3. and 4, respectively: Delete. and substitute new figures 2. 3. and ~ attacbed (pages 3. ~, aa~ 5 ot this notice). (k) Page 32, figure ~7: Delete,and substitute new figure 11 attached (page 6 or this notice). 2.

Retain this Botice and insert before table ot content Custodians: Preparing activity: A.rmy ... AV Navy - AS Bavy ... AS Air Force - II ProJect No. MI6C-Ot.~1 Peae 2 of 6 pages

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Downloaded from https://www.everyspec.com ,""' en !J g NSSL -Normal Steady Stat. Limit. (,) I ASSL- Abnormal Steady « Stat. Limits ESSL- EmergerM:Y Steady State L.imlts .I .2 .5 2 -..l8'~ }A8 "':lefor 500 .01 .02 .05 G .. crQO'l "-Micro .econd. o TIME (SECiONDSJ ~"103 ~"d lit I 'i' '1 P-I O\&l ~ 0 FIGURE 2",. Transient surge ao voltage etsp ~ loci. liIdte tor '0111 v &lw category A equ1pnent i > It "

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Downloaded from https://www.everyspec.com ~!:Il~ """" O'\~ "".1~ I:" '1:1 C1I go ~ ~ '1/D"3 o III ~ ~ I r III '1 '"" ...:a « ~ to > a-. (XI .;: OF EQUIVALENT STEP FUNCTIONS OF THE SEVEREST OVERVOLTAGE SURGE 2001,1:>1"1 ,':' I ,. :~~ en ~ g 1'.:1 I C 40 20 o ~O .01 .02 pt .05 .1 .2 .5 2 5 fO ""-Microlecondt TIME (St:CONDS) FIGURE '3, 'l'ransient surge ac voltaae etep ~10lJ. :tocl1iJdtl for catego1'7 B equ1pnent

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