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).
Proposals on conductor-to-fuse ratios and wiring configurations for the accessory distribution board.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan201 | |
| Date | 23th April 1929 guessed | |
| -4- Contd. we have the 20 to 1 rule for the proportion of the cross section of the conductor to the fuse, that calls for a conductor of 53/36's, so long as a lighter fuse is not put anywhere in the circuit. We are of the opinion that coachbuilders should be instructed that it is for this reason necessary to use quite heavy flexible with which to wire the body lights, a in spite of the fact that the current taken may be comparatively smbll. In our opinion the absolute minimum should be 40/36's, i.e. the same as we use for some of our circuits of lesser importance. We should be pleased to have your agreement concerning our recommendations to these proposals, because we feel that at the present moment the matter is not in an entirely satisfactory state. Perhaps it should be remarked that in view of the fact that the accessory distribution board is on the dash and quite close to the main distribution box and/or ammeter, the provision of the two supply wires to the accessory distribution box,in place of one, would introduce very little disadvantage as compared with the advantage gained. There would, of course have to be some indication on the accessory box as to which two points were supplied via the ammeter and which one point were not. A further suggestion is that all three fuses on the accessory distribution board might be independent with a link to give either two adjacent pairs a common supply. Then if the two supply wires, one via ammeter and one not via ammeter, were connected to the outer fuses, the third or middle fuse could be connected to either supply as desired. EFC. | ||