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).
The correct sizing of conductor wires for accessories in relation to the fuse size.
| Identifier | ExFiles\Box 65\2\ scan0226 | |
| Date | 22th November 1928 | |
| BY.{R.W. Bailey - Chief Engineer} from EFC. X7741a EFC2/T22.11.28. CONDUCTOR WIRES TO ACCESSORIES X7740/1 Referring to my EFC2 & 6/T2.11.28 (0 to E) and to E3/M15.11.28 last para., we suggest that we should take some steps to instruct coachbuilders and others that where accessories are wired from the distribution board or, as will later apply, from the accessory distribution board, the size of the conductor wires should be sufficiently large in relation to the fuse in the circuit as to ensue the blowing of the fuse satisfactorily in the event of a short circuit on the accessory wiring. This means that the accessory conductor wires must be much bigger than is necessary from the normal point of view for supplying the accessory current required. For any electric circuit the size of conductor should be regulated by the size of the fuse in the circuit, and not by the amount of current taken by the apparatus supplied by those conductors. A useful rule would appear to be that the C.S.A. of the conductor should be at least 20 times that of the fuse. EFC. | ||