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).
Instructions on preventing reversed magnetic polarity when reinstalling a dynamo for a 40/50 model.
| Identifier | ExFiles\Box 26\2\ Scan238 | |
| Date | 2nd May 1923 guessed | |
| X. 995. ADDITIONAL WORDING TO PAR. ENTITLED "DYNAMO CONNECTIONS" P.40 UNDER RUNNING INSTRUCTIONS OF ELECTRICAL SECTION OF 40/50 INSTRUCTION BOOK. --------- When, for any reason, the dynamo is removed from the chassis, care should be taken that it is not replaced with reversed residual magnetic polarity, which may result from an electrical test such as running the dynamo as a motor with wrong connections from an independent battery. Should the dynamo be thus replaced, though there is a probability of its being corrected by the chassis battery, there is danger in the process of the cutout contact points being damaged by the arcing which may there occur. To be sure of avoiding this, on first running the engine, after the components have been replaced, the switchbox cover should be removed and the cutout contacts held together by hand for a moment, during which the engine should be accelerated and the charging switch put on. This will ensure the dynamo polarity in relation to the battery being made correct in the first instance and eliminate the possibility of damage to contact points. | ||