a. This British Standard states the requirements for ' Nyvin' type cables for aircraft wiring. The cabies are suitable for use in circuits in which the voltage between conductors, between a' conductor and a metal braid sur-rounding it and berween a conductor and the aircraft structure nowhere exceeds 600 volts r.m.s. and in which the frequency does not exceed 1600 c/s.
the cables are suitable for use where, in continuous service, no combination of ambient temperature and conductor current produces a stabilized conductor tem-perature in excess of 105℃. They are suitable for tixed wiring in aircraft at temperatures down to ?5℃. but are not suitable for severe flexing at temperatures beiow -30℃.
The cables do not support combustion but they do not comply with the requirements of British Standard G. 100 in respect of fire resistance.
The cables are suitable for use in areas where ester-base fluids are present
b. The generic name ' Nyvin' is applicable only to cables covered by this British Standard and complying with all its requirements.
c. The standard includes the following ranges of cables: (i) Nyvin. Cable with a copper conductor and an
insulation of PVC compound and giass braid with an outer protective covering of nylon.
(ii) Nyvinal. Similar to the Nyvin range but with a conductor of aluminium instead of copper.
(iii) Nyvinmer. Similar to the Nyvin range but with the addition of a metal braid.
(iv) Nyvinmctsheath. Similar to the Nyvin range but with the addition of a metal braid and a sheath comprising a polyester film tape, a nylon fibre or ribbon braid, nylon lacquered, to prevent abrasion in installations where Nyvinmet cable is in 〓 with cables without a metal braid.
(v) Dunyvin, Trinyvin, Dunyvinal and Tr.nyvinal. Two-or three-core cables consisting of two or three ? Nyvin or Nyvinal cables twisted together.
d. The cables are classified and identified by a series of numbers indicative of the conductor cross-sectionai arca. The numbers correspond to those used for equivalent American cables. An indication of the relationship between this system of identification and that provided by 〓 Standard E. 21, ' Pren type electric cables for aircraft,' is given in Appendix A for information. The maximum current ratings for Nyvin and Nyvinal cables are quoted in Appendix B.