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).
Design of the electrical distribution system, focusing on fuse protection and wiring for the chassis.
| Identifier | WestWitteringFiles\E\September1920\ Scan11 | |
| Date | 9th September 1920 | |
| To R.R. of America Inc. from R.{Sir Henry Royce} (For attention of OY.) Copy to CJ. " " EFC. ✓ ORIGINAL. R8/G10/9/20. (6) --- X.4173 (crossed out) X.4165 RE ELECTRICAL INSTALLATION ON R.R.CHASSIS. --- I am in receipt of your memo re electrical circuits. You will notice in another memo that we have designed our own electrical distribution system, and that there are fuses in all the circuits and a fuse to the only earth connection which we have, and which is necessary owing to the terminal end of the battery ignition primary circuit running to earth. Our circuits will not only be protected by fuses, but the chassis will be doubly wired throughout with the exception of the battery ignition. Should an accidental contact be made between any of the circuits and the frame, the worst thing that can happen is for the earth fuse to be blown. X.3770 It will be observed that we have not used any fuses between the battery and the dynamo, as the blowing or withdrawal of such a fuse renders it possible for the burning up of the dynamo should the engine be running at its full speed of over 2,000 revs. There is, however, a fuse in connection with the Smith cut-out which it is intended to blow, and therefore but out the excitation of the dynamo in the event of the battery being disconnected. We are not sure, however, that this is a perfectly reliable protection for the dynamo. R.{Sir Henry Royce} | ||