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).
Dynamo high voltage operation, fuse capacity, and potential overheating issues in fuse holders.
| Identifier | WestWitteringFiles\S\September1928-October1928\ Scan096 | |
| Date | 29th September 1928 guessed | |
| -2- Contd. For instance, it is possible for the dynamo to be run continually at a moderately high voltage (about double normal) without the field fuse going, but if the dynamo is run to some higher speed, then the fuse will go. Personally we should like to find some means of getting away from this element of danger, even in circumstances which perhaps may be considered exceptional. Whilst on the subject of fuses, we think it should be pointed out that the limit of current carrying capacity of the fuse holders, without excessive heating of the contacts of the fuse holders in their clips, is practically that of the peak ampere/output of a standard machine. Unless these contacts are carefully done and watched there may be overheating trouble, as we have noticed cases occasionally on the expl. cars in which charring of the insulation of the fuse carrier has taken place. We have not, however, received any complaint of this on production. What we have in mind is that the main dynamo output fuse clips may be overloaded in cases where we put on a higher output dynamo, and we are doubtful if the capacity of the fuse carrier is really sufficient. With this in view we have examined one on chassis 12-G4 to which a higher output 20 H.P. dynamo was fitted. In this case, however, we find the contacts to be good and there is no suggestion of the possible fault referred to. The main fuse wire, however, has just begun to be slightly oxidised, and we believe that once oxidation begins, the wire | ||