ISO 2685 I N T E R N AT I O N AL S T AN D AR D S e co n d e d i ti o n 998-1 2-1 Aircraft — Environmental test procedure for airborne equipment — Resistance to fire in designated fire zones Aé ro n e fs — M é th o d e e m b arq u é s — Te n u e A d ' e s s au fe u en e n vi ro n n e m e n t d an s l es zon es d es é q u i p e m e n ts d ési g n ées « zon es de fe u » R e fe re n ce I SO n u m be r 2685: 998(E) I SO 2685: 998(E) Con ten ts P ag e S co pe D e fi n i ti o n s Te s t e q u i pm e n t Te s t re q u i re m e n ts 4.1 Te s t pro ce d u re 4.1 M o u n ti n g o f s pe ci m e n 4.1 C h o i ce o f bu rn e r 4.1 C al i brati o n o f bu rn e r 4.1 Te s t d u rati o n 4.2 Te s t acce ptan ce co n d i ti o n s Ann exes A E xam pl e s o f bu rn e rs pro vi d i n g th e s tan d ard fl am e B C al i brati o n pro ce d u re fo r bu rn e rs 12 C Te s t co n d i ti o n s fo r fl u i d s ys te m co m po n e n ts 19 D Te s t co n d i ti o n s fo r e l e ctri cal cabl e s an d co n n e cto rs 21 E Te s t co n d i ti o n s fo r s tru ctu ral co m po n e n ts 26 F C o n ve rs i o n facto rs 27 G B i bl i o g raph y 29 © I SO 998 Al l ri g h ts res erved U n l es s o th e rwi s e s peci fi e d , n o part o f th i s pu bl i cati o n m ay be re pro d u ced o r u ti l i z e d i n an y fo rm o r by an y m ean s , e l ectro n i c o r m ech an i cal , i n cl u d i n g ph o to co pyi n g an d m i cro fi l m , wi th o u t pe rm i s s i o n i n wri ti n g fro m th e p u bl i s h e r I n te rn ati o n al Org an i z ati o n fo r S tan d ard i z ati o n C as e po s tal e I n te rn e t • P ri n te d i n S wi tz e rl an d ii CH -1 21 i s o @ i s o ch G e n ève • S wi tz e rl an d © ISO I SO 2685: 998(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work of preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and nongovernmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization Draft International Standards adopted by the technical committees are circulated to the member bodies for voting Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote International Standard ISO 2685 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles This second edition cancels and replaces the first edition (ISO 2685:1 992), of which it constitutes a technical revision Annexes A and B form an integral part of this International Standard Annexes C to G are for information only NOTE — Annexes C, D and E are temporarily maintained for information purposes pending the preparation of standards regarding specific test conditions for the products concerned iii I NTERN ATI ON AL STAN DARD © I SO 2685: 998(E) I SO Ai rcraft — En vi ronmen tal test procedu re for rborne eq u i pmen t — Resi stan ce to fi re i n d esi g n ated fi re zones CAUTI ON — Precau ti ons sh al l be taken to safeg u ard th e h eal th of personn el cond u cti n g tests ag n st th e ri sk of fi re, i n h al ati on of smoke an d /or toxi c produ cts of com bu sti on Scope Th i s I n tern ati onal Standard specifi es the tests di ti on s appli ed to al l componen ts, equ i pm ents an d stru ctu res l ocated i n zon es desi g n ated as "fi re zon es" an d bu i l t to sati sfy th e m i n i m u m speci fi ed l evel for resi stance to fi re Two g rades of resi stance to fi re are appl i cabl e to com pon en ts, equ i pm en ts an d stru ctu res An n exes A an d B g i ve detai l s of th e types of bu rn ers provi di n g th e standard fl am e an d h ow th ey sh al l be u sed Thi s I ntern ati on al Standard does n ot relate to th e resistance to fi re ou tsi de desi g n ated fi re zon es, n or to fl amm abi l i ty requ i rem en ts, n or to th ose di ti on s i ndu ced by th e fl am e comi n g from th e com bu sti on ch amber Defi n i ti on s For th e pu rposes of th i s I ntern ati on al Standard, th e fol l owi n g defi n i ti on s appl y d esi g n ated fi re zon e: Regi on of an rcraft, for exam pl e com partmen ts tai n i n g m n eng i nes an d au xi l i ary power u ni ts, desi g n ated as su ch by th e rcraft desi g n er i n accordan ce wi th th e requ i rem en ts of th e approvin g au th ori ty 2 stan d ard fl am e: Fl am e h avi n g th e fol l owi n g ch aracteristi cs: – tem peratu re: 1 00 °C ± 80 °C – h eat fl u x den si ty recei ved by th e standard apparatus descri bed i n B 2: (1 ± 0) kW/m fi re resi stan t: G rade desi gn ati n g componen ts, equ i pmen ts an d stru ctu res capable of wi th standi ng th e appl i cati on of h eat by a standard fl am e for m i n fi reproof: G rade desi g n ati ng com pon ents, equ i pmen ts and stru ctu res capable of wi th standi n g th e appl i cation of h eat by a standard fl am e for m i n Test eq u i pm en t Th e bu rn er sh al l produ ce a fl am e h avi n g th e ch aracteristi cs of th e stan dard fl am e Exam pl es of th i s bu rn er (g as or l i qu i d fu el ) are g i ven i n an n ex A I SO 2685: 998(E) Test req u i rem en ts Test proced u re © I SO Th e fol l owin g procedu re appli es to al l th e fi re tests Parti cu l ar di ti on s to be appl i ed du ri n g the fi re tests sh al l be detai l ed i n th e specifi cation of th e equ i pm en t u n der si deration Mou n ti n g of specim en Th e componen t, equ i pm en t or stru ctu re sh al l be i n stal l ed on a test ri g defi n ed i n th e specifi cati on of th e equ i pm en t u n der si derati on , i n condi ti on s at l east equ i val en t to th ose en cou n tered i n th e rcraft Ch oi ce of bu rn er Th e type an d nu m ber of bu rn ers shal l be ch osen su ch th at, du ri n g the fi re test, th e cri ti cal parts of th e com pon en ts or i tem s of equ i pmen t are en vel oped i n th e test fl am e(s) from th e appropriate di recti on (s) For that, the fol l owin g di ti on s shal l be fu l fi l l ed: A ≤ 2B wh ere A i s th e m aj or cross-section of th e equ i pm en t or speci m en , i n squ are m etres; B i s the area of th e fl am e at th e n ozzl e of th e bu rner, i n squ are m etres Th e n omi nal axi al di stance between the bu rn er nose(s) an d th e su rface of th e i tem u n der test sh al l be as defi n ed i n an n ex A 4.1 Cal i brati on of bu rn er Th e bu rn er sh al l be cal i brated i n accordan ce wi th an n ex B 4.1 Test d u rati on Th e com pon en t or i tem of equ i pmen t to be tested sh al l be su bj ected to the stan dard fl am e for th e du rati on correspondi n g to i ts g rade of resi stance to fi re, i e : – m i n for a "fi re resi stan t" cl assi fi cati on (see 3) ; – m i n for a "fi reproof" cl assi fi cati on (see 4) Test acceptan ce d i ti on s As di ti on s of acceptance, the i tem sh al l be capable of wi thstandi n g th e fi re test correspondi ng to the appropriate requ i rem en ts an d/or to i ts detai l ed speci fi cati on © I SO I SO 2685: 998(E) An n ex A (norm ati ve) Exam pl es of bu rn ers provi d i n g th e stan d ard fl am e A G as bu rn er A A.1 Eq u i pm en t Su ppl y of l ow pressure compressed r The actual pressu re requ i rem en t wi l l depend on h ow th e u ser sets u p th e equ i pm en t, bu t a l ow pressu re su pply (for exampl e 35 kPa) wi th a free r fl ow of 25 m /h i s u su al l y su ffi ci en t Al tern ati vel y, tappin g a h i g h er pressu re su pply th rou g h a regu l ator i s acceptable A.1 Means of control l i n g and setti n g g as and r su ppl i es M ean s of troll i ng an d setti ng gas an d air su ppli es i n cl u de m anu al valves an d m eteri n g devi ces to m easu re di fferenti al pressu re of gas an d r, an d, eventu al l y, featu re val ve u pstream pressu re m on i tori ng For fl ow setti ng , fi g u re A i n di cates h ow to proceed u si n g di fferenti al pressu re across each ori fi ce N OTE — BS 3G 00 part 2, secti on 3, su bsecti on 3 (1 983) sh ows m easu ri n g devi ces m ou n ted wi th th e bu rn er h ead , bu t i t h as been establ i sh ed th at th ey can be u sed sati sfactori l y at a sol e u p to m away i f n ected to th e bu rn er by pi pes wi th a m i n i m u m bore d i am eter of m m A Detai l s of th e bu rn er Th e desi g n of th e bu rn er i s sh own i n fi gu res A , A an d A and a photograph of th e bu rner i s sh own i n fi g u re A I m portant featu res i n cl u de: a) the m ean s of m i xi n g g as an d r for com bu sti on at th e "m i xi n g base"; b) the desi gn of th e fl am e h ead; c) th e m ean s of i n trodu ci n g cool i n g r wi th i n th e stru ctu re of th e fl am e h ead A.1 2.1 Mi xi n g base Ai r an d g as are i ntrodu ced an d m i xed i n a sm al l ch amber From th i s cham ber, th e m i xed g as and r en ters a l arger pl en u m ch am ber before reachi n g th e fl am e h ead A.1 2.2 Bu rn er h ead The bu rner h ead m u st act as a fl am e stabi l i zer and prevent fl ash back i n to th e pl en u m cham ber tai ni n g th e com bu sti bl e m i xtu re To th i s, th e bu rn er i s m ade u p of 373 copper tu bes whi ch are cool ed by r fl owi n g arou nd th em Th e cooli n g r i s su ppli ed th rou gh 332 h ol es at th e fl ame h ead, th u s m n tai n i n g th e bu rn er temperatu re at th e l evel requ i red for th e test © ISO I SO 2685: 998(E) A.1 2.3 Cool i n g r The cooling air shall be well-distributed within the structure of the flame head for the purpose described in A.1 2.2 The top plate and tubing, shown in figure A.1 , are designed to produce the correct overall effect A A Fl am e setti n g Li g h ti n g It is easier to light the burner when the gas flow is reduced, but gas-rich The following procedure is recommended: – turn on the gas at a flow rate of about 0,5 m 3/h (1 mm differential water pressure); – ignite the gas; – if ignition does not occur within a few seconds, turn off the gas, purge the burner with mixing air and wait for lowlying gas near the burner to disperse; – when ignition occurs, introduce mixing and cooling air, then immediately increase the gas flow rates and air flow rates to the intended level; – in order for the heating conditions to stabilize, allow the apparatus to run for at least before calibrating the burner or starting the test A.1 3.2 G as and r d i fferenti al pressure setti n g s Table A.1 gives the typical gas and air settings needed to achieve the characteristics of the standard flame according to the metering devices of figure A.3 Tabl e A.1 — Typi cal setti n g s for fi re testi n g Gas Mixing air Cooling air 440 Pa 265 Pa 940 Pa (45 mmH 2O) (435 mmH 2O) (300 mmH 2O) NOTE — The above values may need adjusting to achieve the characteristics of the standard flame (see 2.2) and are established for a calorific value close to 93 000 kJ/m Di fferen ti al pressu re A Cal i brati on The burner shall be calibrated in accordance with annex B and shall meet the requirements for the standard flame (see 2.2) The nominal axial distance, h , between the burner nose and the surface of calibration equipment in practice is close to 75 mm (see figures A.1 , B.2 and B.3) A Di stan ce between bu rn er an d test speci m en The nominal axial distance h ± %, between the burner nose and the surface of the test specimen, shall be the one determined by the calibration of the flame A Sh u t-d own After the test, the gas shall be turned off first The air flow shall be turned off only when the burner has cooled sufficiently © ISO A I SO 2685: 998(E) Li q u i d fu el bu rn er The details of the liquid fuel burner specified in this annex are equivalent to those found in FAA Powerplant Engineering Report No 3A A typical liquid fuel burner complying with the requirements of this annex is shown in figure A.5 A Detai l s of th e bu rn er The liquid fuel burner shall : a) be of a modified gun type; b) have an 80° spray angle nozzle, nominally rated at 8,5 l/h (assuming a typical fuel calorific value of 42,8 x 03 kJ/kg); c) have a 31 mm burner nozzle fixed at the end of the tube, with a 52 mm high and 280 mm wide opening, as shown in figures A.6 and A.7; and d) have a burner fuel pressure regulator that is capable of adjusting the fuel flow to achieve the characteristics of the standard flame (see 2.2) A 2 Fl am e setti n g The burner shall be lit and adjusted in accordance with the manufacturer's instructions The flame shall be allowed to stabilize for at least before calibration or testing A Cal i brati on The burner shall be calibrated in accordance with annex B and shall meet the requirements for the standard flame (see 2.2) The nominal axial distance h between the end of the burner nozzle and the calibration equipment in practice is close to 00 mm (see figures A.6, B.2 and B.3) A Di stan ce between bu rn er an d test speci m en The nominal axial distance h ± % between the end of the burner nozzle and the test specimen shall be the one determined by the calibration of the flame I SO 2685: 998(E) © I SO D i m e n s i o n s i n i n ch e s , i n m i l l i m e tre s i n pare n th e s e s Fi g u re A — G as bu rn er I SO 2685: 998(E) © I SO D i m e n s i o n s i n m i l l i m e tre s M ateri al : brass Fi g u re B — Redu ci n g fi tti n g of th e stand ard h eat fl u x d ensi ty m easu ri n g tu be D i m e n s i o n s i n m i l l i m e tre s M ateri al : al u m i n i u m tu be brass fi tti n g s Fi g u re B — Su ppl y fi tti n g of th e stan d ard h eat fl u x d en si ty m easu ri n g tu be 16 © I SO 2685: 998(E) I SO D i m e n s i o n s i n m i l l i m e tre s M ateri al : al u m i n i u m tu be Fi g u re B — Exi t fi tti n g of th e stand ard h eat fl u x d ensi ty m easu ri n g tu be D i m e n s i o n s i n m i l l i m e tre s M ateri al : brass D i m en si o n s: fu n cti o n o f th e th erm o m eter Fi g u re B — Exampl e of m ou n ti n g of th e th ermometer of th e stand ard h eat fl u x d en si ty m easu ri n g tu be 17 © ISO I SO 2685: 998(E) Dimensions in millimetres Fi g u re B — Overall vi ew of th e stand ard h eat fl u x d ensi ty m easu ri n g tu be 18 © I SO I SO 2685: 998(E) An n ex C (i n form ati ve) Test d i ti on s for fl u i d system com pon en ts C G en eral Th i s an n ex speci fi es th e parti cu l ar test d i ti on s for fl am m abl e fl u i d systems an d pn eu m ati c system s com pon en ts C Stan d ard fl am e Th e com pon en t u n d er test sh al l be su bj ected to a stan d ard fl am e (see 2 an d an n ex A) C Vi brati on Fl exi bl e h ose assem bl i es an d com pon en ts sh al l be vi brated al on g or perpendi cu l ar to th e axi s of th e com pon en t at a frequ en cy of 33 H z an d wi th a m i n i m u m am pl i tu d e of , m m C Parti cu l ar d i ti on s C Pressu re Th e pressu re sh al l be th e workin g pressu re of th e com pon en t or, wh ere specifi ed , th e system pressu re m ay be su bsti tu ted du ri n g th e test C Fl ow rates U n l ess m ore cri ti cal fl ow rates are specifi ed for th e parti cu l ar i n stal l ati on , th e fl ow rates for th e fu l l test peri od sh al l be g i ven as i n C to C N OTE — Fi re tests i n accord an ce wi th th e Am eri can stan d ard SAE AS 055 D for eq u i val en t fl ow rates are si d ered eq u i val en t q u al i fi cati on C.4.2.1 – Fu el and l u bri cati n g systems Pi pes an d fl exi bl e h ose assem bl i es: fl ow rate, i n l i tres per m i n u te, sh al l be equ al to 0, 03 d wh ere d i s th e i n tern al d i am eter, expressed i n m i l l i m etres – Oth er com pon en ts: th e fl ow rate sh al l be d etermi n ed i n th e sam e way u si n g th e i n tern al d i am eter of th e i n l et cou pl i n g Th e fl u i d sh al l be th e system fl u i d or equ i val en t C.4.2.2 – Hyd rau l i c systems Pi pes an d fl exi bl e h ose assem bl i es: fl ow rate, i n l i tres per m i n u te, sh al l be equ al to 0, 006 d wh ere d i s th e i n tern al d i am eter, expressed i n m i l l i m etres – Oth er com pon en ts: th e fl ow rate sh al l be d etermi n ed i n th e same way, u si n g th e i n ternal d i am eter of th e i n l et cou pl i n g Th e fl u i d sh al l be th e system fl u i d or equ i val en t C.4.2.3 Pneu m ati c systems Th e fl ow rate i n pn eu m ati c pi pes, h oses an d com pon en ts sh al l be zero u n l ess oth erwi se speci fi ed 19 I SO 2685: 998(E) C © I SO Test proced u re for h oses Th e h o s e to be tes te d s h al l be n o t l e s s th an 60 cm l o n g H o s es s h al l be m o u n ted h o ri z o n tal l y an d s h al l i n cl u d e o n e ° be n d On e en d fi tti n g an d at l e as t cm o f h o s e s h al l be e n ve l o pe d by th e te st fl am e C Fl u i d tem peratu re C Li q u i d Th e tem pe ratu re of th e fu e l , l u bri can t or h yd rau l i c fl u i d i n si de h oses s h al l be at l e as t °C to 1 °C Th e fl u i d te m pe ratu re fo r o th er co m po n e n ts sh al l be th e s am e u n l e ss o th e rwi s e spe ci fi e d C Th e Pn eu m ati c te m pe ratu re of th e r or g as i n si de th e co m po n e n t s h al l be n ot l ess th an th e m axi m u m n o rm al d es i g n te m pe ratu re C Test acceptan ce cri teri a C Fu el , l u bri cati n g an d h yd rau l i c system s In ad d i ti o n to co m pl yi n g wi th , s ys te m co m po n e n ts s h al l sh ow no e vi d e n ce of l e akag e o ve r th e te s t pe ri o d s pe ci fi e d i n C In Pn eu m ati c system s ad d i ti o n to co m pl yi n g pe ri o d s pe ci fi e d i n 20 wi th , s ys te m co m po n e n ts s h al l sh ow n o e vi d e n ce of s i g n i fi can t l e akag e o ve r th e te s t © I SO I SO 2685: 998(E) An n ex D (i n form ati ve) Test d i ti on s for el ectri cal cabl es an d n ectors D G en eral Th i s an n ex speci fi es th e parti cu l ar test d i ti on s for el ectri cal cabl es an d n ectors D Vi brati on Th e cabl e or n ector specim en sh al l be vi brated across th e axi s of th e com pon en t at a frequ en cy of between 30 H z an d 60 H z an d wi th a m i n i m u m accel erati on of g n D D Parti cu l ar d i ti on s for el ectri cal cabl es Stan d ard fl am e Th e cabl e speci m en sh al l be su bj ected to a stan d ard fl am e (see 2 an d an n ex A) D Si n g l e core cabl es Th ree test speci m en s 0, 75 m l on g sh al l be sel ected at ran d om from a q u an ti ty of cabl e an d prepared for test i n th e fol l owi n g m an n er Each l en g th of cabl e sh al l h ave th e m i d d l e h al f-m etre i m m ersed i n on e of th e l i sted fl u i d s at am bi en t tem peratu re for 24 h A separate typi cal speci m en sh al l be u sed for each fl u i d: a) avi ati on fu el ; b) en g i n e l u bri cati n g oi l ; c) h ydrau l i c oi l After rem oval of su rpl u s fl u i ds from th e cabl es, each l en g th i n tu rn sh al l be m ou n ted on to a frame as sh own i n fi g u re D Each sam pl e sh al l be wrapped on ce arou n d wi th two n i ckel -ch rom e ri bbon s wi th th ei r i n n er edg es spaced 25 m m ± mm apart Th e sampl e an d test ri bbon s sh al l be wei g h ted, as sh own i n fi g u re D , an d th e test assem bl y adj u sted so th at th e area wrapped by th e ri bbons i s l ocated at th e appropriate di stance above th e bu rn er wh ere th e tem perature i s 1 00 °C After ten si on i n g wi th wei g h ts, th esam pl es an d test ri bbon s sh al l be l ocked at th e pu l l ey posi ti on to avoi d th e wei g h ts g i vi n g h i g h l oadi n g u n d er vi brati on /resonan t d i ti on s Th e test sam pl e sh al l be n ected to a ci rcu i t as sh own i n fi g u re D Sampl e ti n u i ty i s sh own wh en a cu rrent fl ow of A i s reg i stered wi th th e el ectri cal su ppl y swi tch ed on Th e i n su l ati on d eg radati on d etection ci rcu i t sh al l be ch ecked by depressin g th e test swi tch ; an i n d i cati on of 25 m A fl ow sh ou l d be reg i stered D 3 Mu l ti -core cabl es Th ree test speci m en s sh al l be prepared for test as d escri bed i n D Each test speci m en sh al l be m ou n ted on to th e test frame over th e bu rn er i n a m an n er si m i l ar to th at sh own i n fi g u re D , u si n g th e appropriate wei g h t Th e test sam pl es sh al l i n tu rn be n ected to a ci rcu i t as sh own i n fi g u re D 3, test Pre-test ch ecks sh al l be carri ed ou t as d escri bed i n D Vi brati on on th e m ou n ti n g fram e sh al l be as d escri bed i n D 21 I SO 2685: 998(E) D © I SO Mu l ti -screen ed cabl es M u l ti -core screened cabl es are overal l screen (m etal brai d ) cabl es i n cl ose tact wi th th e i n d i vi d u al cores Th ree test speci m en s sh al l be prepared for test as d escri bed i n D Each test speci m en sh al l be m ou n ted on to th e test frame over th e bu rn er i n a m an n er si m i l ar to th at sh own i n fi g u re D , u si n g th e appropriate wei g h t Th e test sam pl es sh al l i n tu rn be n ected to a ci rcu i t as sh own i n fi g u re D 3, test Pre-test ch ecks sh al l be carri ed ou t as d escri bed i n D Vi brati on on th e m ou n ti n g fram e sh al l be as d escri bed i n D D Acceptan ce cri teri a Th e cables sh al l be d ecl ared fi re resi stant i f th ere i s ti n u i ty th rou g h th e test speci m en for m i n of fl am e i m pi n g em en t, an d th e resi stan ce of th e i n su l ati on du ri n g th e same peri od i s n ot l ess th an 000 Ω I f th e cable i s to be d ecl ared fi reproof, th e test peri od sh al l be exten d ed to m i n D D Parti cu l ar d i ti on s for el ectri cal n ectors Stan d ard fl am e Th e n ector sh al l be su bj ected to a stan dard fl am e (see 2 an d an n ex A) D Wi ri n g of speci m en n ector Th e n ector sh al l be wi red as sh own i n fi g u re D 4, u si n g fi re resi stant wi ri n g Each contact sh al l be n ected i n seri es Th e l oad sh al l be set to g i ve a stan t cu rren t equ al to th e n om i n al val u e speci fi ed for th e conn ector D Mou n ti n g of n ector speci m en Th e m ated conn ector pai r, tog eth er wi th th e requ i red accessories, sh al l be m ou n ted as sh own i n fi g u re D D 4 Acceptan ce cri teri a Conn ectors wi th a requ i rem en t for el ectri cal fu n cti on i n g sh al l be d ecl ared fi re resi stan t i f n o el ectri cal fai l u re occu rs over a peri od of m i n Du ri n g th e m i n appl i cati on of th e fl am e, swi tch sh al l be cl osed an d swi tch sh al l be open After m i n , open swi tch an d cl ose swi tch El ectri cal fai l u re wi l l be assu m ed i f, d u ri n g th e fi rst m i n , th ere i s an y el ectri cal d i scon ti n u i ty or i f, d u ri n g a fu rth er m i n , th ere i s an y l eakage i n excess of th e val u e speci fi ed for th e n ector I n th e case of n ectors i n ten ded for u se i n fi rewal l appl i cati on s, n o fl am e sh al l pass from on e si de of th e m ou n ti n g pl ate to th e oth er, n or sh al l th ere be an y spontan eou s i g n i ti on on th e si d e of th e pl ate away from th e fl am e, over a peri od of m i n Th e above tests m ay be carri ed ou t si m u l tan eou sl y 22 © I SO I SO 2685: 998(E) Fi g u re D — El ectri cal cabl e test ri g Procedu re: a) N ote th e l i n e cu rren t (approxim atel y A) b) Operate th e swi tch an d observe a 25 m A readi n g c) Leakage cu rren t fl ow sh al l n ot exceed 2, m A d u ri n g th e test peri od Fi g u re D.2 — Ci rcu i t d i ag ram for si n g l e-core cabl es 23 I SO 2685: 998(E) © Procedu re: a) N ote th e l i n e cu rren t (approxim atel y A) b) Operate th e swi tch an d observe a 25 m A readi n g c) Leakage cu rren t fl ow sh al l n ot exceed 2, m A d u ri n g th e peri od of tests an d Fi g u re D.3 — Ci rcu i t d i ag ram for m u l ti core cabl es Fi g u re D — Test ci rcu i t d i ag ram for conn ectors 24 I SO © ISO I SO 2685: 998(E) Dimensions in millimetres Fi g u re D — Test ri g for conn ectors 25 I SO 2685: 998(E) © I SO Ann ex E (i n form ati ve) Test d i ti on s for stru ctu ral com pon en ts E Th i s G en eral an n ex speci fi es th e parti cu l ar test d i ti on s for stru ctu ral com pon en ts (for exam pl e en g i n e m ou n ti n g s, cowl i n g s, fi rewal l s) E Stan d ard fl am e Th e com pon en t sh al l be su bj ected to a stan d ard fl am e (see 2 an d an n ex A) E Vi brati on Com pon en ts sh al l be vi brated at an am pl i tu d e of 0, m m at th e n on -resonan t freq u en cy cl osest to 50 H z I t i s expected th at al l m etal l i c m atri x stru ctu res, n on -m etal l i c stru ctu res an d oth er n on -m etal l i c fi re barri er coati n g s wi l l be vi brated du ri n g th e fi re-test Larg e m etal l i c stru ctu res m ay n ot be requ i red to be vi brated E Test peri od s For th e fi rst m i n of th e test, stru ctu ral com pon en ts sh al l be tested wh i l e su bj ected to l oads correspond i n g to n orm al m an oeu vres an d an y su peri m posed l oads resu l ti n g from vi brati on n orm al l y experien ced i n fl i g h t After th e fi rst m i n , fi reproof g rade tests sh al l be carri ed ou t u si n g l oads correspond i n g to th ose wh i ch apply after en g i n e sh u t-down E Acceptan ce cri teri a Stru ctu ral componen ts sh al l m eet th e acceptance cri teri a of an d sh al l be capabl e of wi th stan di n g th e l oads specifi ed i n E th rou g h ou t th e test peri od 26 © I SO I SO 2685: 998(E) Ann ex F (i n form ati ve) Con versi on factors N OTE — F I n cl au ses F , F an d F 5, exact val u es are pri n ted i n bol d face type Len g th m mm ft in 1 000 3, 280 84 39, 370 0, 001 0, 003 28 0, 039 37 0, 304 304, 12 0, 025 25, 0, 083 33 1 m (m etre) mm (m i l l i m etre) ft (foot) in (i n ch ) F Vol u m e fl ow rate US UK g al /m i n g al /m i n 0, 832 67 0, 227 , 200 95 0, 272 77 4, 402 86 3, 666 m /h U S g al /m i n (U S g al l on per m i n u te) U K g al /m i n (U K g al l on per m i n u te) m ³/h (cu bi c m etre per h ou r) F Pressu re l bf/i n l bf/i n i n H 2O kPa m bar 0,036 27 6,894 76 68,947 27,680 1 0,249 089 2,490 89 0,1 45 04 4,01 63 10 0,01 504 0,401 463 0, 1 (pou nd force per sq u are i n ch ) i n H 2O (i n ch of water) kPa (ki l opascal ) m bar (m i l l i bar) 27 I SO 2685: 998(E) F © I SO Tem peratu re Deg rees Cel si u s = (d eg rees Fah ren h ei t F − 32) H eat an d rel ated val u es H eat: CH U (cen ti g rade h eat u n i t) = , Btu (Bri ti sh th erm al u n i ts) Btu (Bri ti sh th erm al u n i t) = , 055 06 kJ (ki l oj ou l es) Cal ori fi c val u e (vol u m e basi s) kJ /m (ki l oj ou l es per cu bi c m etre) = 26, 839 × 10 -6 Btu /ft (Bri ti sh th erm al u n i ts per cu bi c foot) Cal ori fi c val u e (mass basi s) Btu /l b (Bri ti sh th erm al u n i t per pou n d ) = 2,326 kJ /kg (ki l oj ou l es per ki l og ram ) Power: CHU/s (centigrade heat unit per second) = , 899 kW (ki l owatts) Btu /s (Bri ti sh th erm al u n i t per second ) = , 055 06 kW (ki l owatts) H eat fl u x d en si ty CH U /(ft · s) (cen ti g rade h eat u n i t per squ are foot secon d ) = 20, 441 74 kW/m Btu /(ft · s) (Bri ti sh th erm al u n i t per squ are foot second ) = 1 , 356 52 kW/m F Accel erati on g n = 9, 806 65 m /s 28 (m etres per secon d squ ared) 2 (ki l owatts per squ are m etre) (ki l owatts per squ are m etre) © I SO I SO 2685: 998(E) An nex G (i n form ati ve) Bi bl i og raph y [1 ] I SO 228-1 :1 994, Pi pe th reads wh ere pressu re-ti g h t j oi n ts are n ot m ade on th e th reads — Part : Di m en si on s, tol eran ces an d designation [2] BS 3G 00, Part 2, Secti on 3, Su b-secti on 3: 973, Speci fi cati on for g en eral requ i rem en ts for equ i pm en t fo r u se i n rcraft Al l equ i pm en t En vi ron m en tal di ti on s Resi stan ce to fi re i n desi g n ated fi re zon es [3] FAA Powerpl an t En g i n eeri n g Report n ° 3A, Stan dard Fi re Test Apparatu s an d Procedu re , M arch 978 [4] FAA AC 20-1 35, Powerplan t i n stal l ati on an d propu l si on system com pon en t fi re protection — Test m eth od s, stan d ard s an d cri teri a [5] AS1 055D: 997, Fi re testi n g of fl exi bl e h ose, tu be assem bl i es, coi l s, fi tti n g s, an d si m i l ar system com pon en ts 29 I SO 2685: 998(E) © I SO I CS 49 020 Descri ptors: rcraft, rcraft e q u i pm e n t P ri ce bas e d o n pag e s e q u i pm e n t, te s ts , e n vi ro n m e n tal te s ts , fi re te s ts , d e te rm i n ati o n , fi re res i s tan ce , te s ti n g co n d i ti o n s , tes t