From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Electrical system requirements for heavy and small current accessories, such as a cigar lighter.
| Identifier | ExFiles\Box 65\2\ scan0223 | |
| Date | 1st November 1928 | |
| To E.{Mr Elliott - Chief Engineer} from EFC. c.c. EY BY/RD. X7741 EFC6/T2.11.28. SS.{S. Smith} ELECTRICAL SYSTEM. X7740 ------------------- Further to our EFC2/T2.11.28, it is now pointed out that some accessories, e.g. a cigar lighter, may demand a current as heavy as 15 or more amperes, and it is queried whether the 15 ampere fuse wire will be heavy enough for such an accessory. To be quite logical, accessories demanding heavy currents should be supplied independently from the main distribution board through a 30 ampere fuse, and the accessory wiring should be of corresponding size. It might be a good rule, for instance, that the wiring of every circuit should be at least 20 times the section of the fuse in that circuit, e.g. if a fuse is 30 S.W.G. copper, the conductor wires should not be less than the equivalent of 53/36. Accessories taking small currents, such as body lights, fans, etc., should logically be fed as a group through one main fuse on the main distribution board, and separately through separate fuses on the accessory distrib- ution board. This is what you have provided - the difficulty is the case of a heavy current accessory like a cigar lighter. EFC. | ||