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).
Experiments and assembly instructions for cartridge type electrical system fuses.
| Identifier | ExFiles\Box 166\7\ img021 | |
| Date | 5th September 1933 | |
| 86071. E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. c. to By.{R.W. Bailey - Chief Engineer} c. to PN.{Mr Northey} c. to EP.{G. Eric Platford - Chief Quality Engineer} Hs{Lord Ernest Hives - Chair}/Wst.1/MA.5.9.33. R.R. ELECTRICAL SYSTEM FUSES. Further to our Hs{Lord Ernest Hives - Chair}/Wst.1/MA.26.5.33.., we have carried out further experiments with cartridge type fuses following our recommendation for the exclusive use of the cartridge type on our chassis. Our tests further confirmed that this type of fuse gives the most satisfactory and consistent results and as you now have a design in hand for a distribution board fitted with these fuses we are sending you the following notes we have made up as a result of our tests. Cartridge type chassis electrical fuse. In assembling fuses the wire should be just held taut, it should not be stretched tight or allowed to hang loose. If the latter is not observed then when the wire is heated it will sag due to expansion and touch the side of the glass container, in the case of the cartridge type, thereby increasing the current carrying capacity of the fuse. In the case where the wire is stretched tight the carrying capacity is reduced due to the tension reducing the wire diameter. The glass container or cylinder should have an internal diameter large enough to prevent the fuse wire from touching the walls of the container when the former is hot. The metal fuse caps and holders should be of ample size so that the heat generated in the fuse wire is dissipated efficiently thus preventing the solder melting. | ||