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).
Properties and selection of appropriate fuse wire.
| Identifier | ExFiles\Box 61\2\ scan0403 | |
| Date | 1st October 1920 | |
| X.26787- To Wd.{Mr Wood/Mr Whitehead} from EFC. c. to Wd{Mr Wood/Mr Whitehead}/Ms. c. By.{R.W. Bailey - Chief Engineer} EFC4/T1.10.20. X.2515 - FUSE WIRE. We have recently received from the London Electric Wire Co. 5 samples of fuse wires; two under cover of their letter ref: R of Sept. 6th of No.17 and No.30 S.W.G., and three under cover of their letter ref: R of Sept. 28th of Nos. 17, 18 and 30 S.W.G. The average fusing currents of these in their appropriate fuse holders we find to be as follows :- First sample No.17 S.W.G. 49 amperes. " " " 30 " 3.55 " Second " " 17 " 65.5 " " " " 30 " 5.3 " Specimen No.18 S.W.G. 52.0 " Fuse wire at present being used for Lucas junction box of 19 S.W.G. 24.0 amps. It will be seen from the above that neither No.17 specimen is suitable for the junction box fuse, further that there is a great difference in the material of these wires, which alters the fusing current although of the same diameter. What we require is a wire that will fuse at about 30 to 35 amps. in the junction box in place of the originally specified 25, with which our present standard agrees. It would appear that the right wire to ask for is of the same gauge 19 S.W.G. as our present standard but made in the harder material, of which these later samples have been made. There should be little difficulty in obtaining this. Contd | ||