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).
Minor criticisms and suggestions for an electrical installation diagram.
| Identifier | ExFiles\Box 65\2\ scan0137 | |
| Date | 25th September 1928 | |
| To E.{Mr Elliott - Chief Engineer} from EFCt c.c. BJ. BY.{R.W. Bailey - Chief Engineer} X7740 EFC2/T25.9.28. EAC.10. ELECTRICAL INSTALLATION. Lec.2595. EL/M22.9.28. X 7780 There are one or two rather minor criticisms which we think it just worth while to make in connection with Lec.2595:- (1) The lever side of the motor armature operated switch is not included as being earthed to frame, as would seem to be desirable for the sake of completeness. (2) One one of your previous diagrams we noticed that the switchbox was labelled "Switchbox from rear". We think perhaps it would be desirable to indicate that on this diagram also. (3) Though probably only diagrammatic, we notice that your charging switch would appear to show that the field circuit is broken last by the switch, whereas you will remember that we advocated that the field circuit shall be broken first, so that when the armature circuit breaks it breaks dead. Incidentally it might be mentioned that if you are not too far on with the design of this switch it is some advantage to make the time between the two breaks as large as possible so that if the switch is operated very quickly there is more time for the dynamo to dis-excite between one break and the other. (4) Your arrows showing the directions of the current may perhaps be considered not quite consistent in this respect - that you show the battery discharging, whereas you show the dynamo charging. We should think that it is | ||