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).
Examination of a dynamo, distribution box, and switch fault on chassis 50-RC, identifying a design weakness.
| Identifier | ExFiles\Box 70\3\ scan0200 | |
| Date | 1st September 1926 | |
| X878361 To BY.{R.W. Bailey - Chief Engineer} from EFC. c. Mr. Brock. EFC5/T1.9.26. CHASSIS 50-RC.{R. Childs} DYNAMO, DISTRIBUTION BOX AND SWITCH. We have duly examined these units and though we agree that the owner has been careless in his subsequent treatment of the distribution box, we think the evidence goes to shew that the original fault was an RR. one of poor contact between the bolt to which dynamo A wire is attached and the base of the fixed cutout contact point support, and there must have been a high temperature at this point because it is clear that the solder underneath the base has run. We think that the subsequent charring of the dynamo B fuse holder and a partial burning of the series winding, and the condition of the dynamo itself, is probably due to the effect of the high voltage and current at which the dynamo has been running as a result of the poor contact referred to. We should not view this entirely as defective production. We consider there is a definite weakness in the design at this point which should be corrected. Apparently there is only a spring/pressure washer connection at this point which has to carry the whole external output of the dynamo. Further, it has to be remembered that the current at this point, being the negative brush current, the connection at this point is as previously explained even more important than at some of the other points in the system, as for instance, connections at the B dynamo fuse. We are of the opinion that there should be a better designed terminal for this A wire | ||