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).
Grading and sizing of fuse wire for main and accessory electrical distribution boards.
| Identifier | WestWitteringFiles\T\November1928\ Scan006 | |
| Date | 2nd November 1928 | |
| To E.{Mr Elliott - Chief Engineer} from EFC. c. BY.{R.W. Bailey - Chief Engineer} BY/RD. ORIGINAL EFC2/T2.11.28. X7745/1 SS.{S. Smith} ELECTRICAL SYSTEM. Referring to your LeC's 2595/6/8 and the question of fusing, it has been noted that you have indicated two strands of fine wire for the main distributing fuses in the distribution box, and a single strand of fuse wire for the distributing fuses on the accessory distribution box. We assume that this is R's proposal for grading the sizes of fuses without using two sizes of wire. It will therefore be necessary for us to fix upon some smaller size of copper wire than the present 30 S.W.G. and make it quite clear to all concerned that two strands must be used on the main distribution board and one strand only on the accessory distribution board. I should be pleased if you would confirm that this is the intention. We consider it most desirable that the fuses on the accessory distribution board should be lighter, and we should have said 30 ampere for the main distribution board as at present, and 10 ampere for the accessory distribution board. At present the body lighting is sometimes run on such relatively fine wires that if a short occurred, say at a lamp socket, the wires might be burnt up before the main 30 ampere fuse relieved the situation. It is therefore most desirable to have finer fuses to protect such finer circuits. In places where we cannot have finer fuses, e.g. the supply to the inspection lamp socket and instrument board lights, then it is definitely better to run wires of heavy section, even through only a small current is required through them. | ||