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).
Proposal of a 'semi-earthed electrical system' for the E.A.C. chassis.
| Identifier | ExFiles\Box 61\2\ scan0199 | |
| Date | 24th October 1923 | |
| X3374 To R & E.{Mr Elliott - Chief Engineer} from EFC. c. CJ. & BJ. c. BY.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} DA.{Bernard Day - Chassis Design} c. Wor.{Arthur Wormald - General Works Manager} CK.{Mr Clark} EFC4/T24.10.23. X.9960 - E.A.C. CHASSIS ELECTRICAL SYSTEM. X.3374. X.9560. X.4087 We should like again to put before you for your consideration, more particularly in connection with the E.A.C. electrical system, the arrangement of connections which we call "the semi-earthed electrical system". Our reason for this is that we consider such a system combines in a general way the advantages of both the insulated and the earthed systems and is therefore the most generally or alround satisfactory solution of the problem when armature reaction control of the generator unit is utilised. The system is shown diagrammatically on the attached blueprint. As compared with a completely insulated system, the difference is that the return currents of ignition, lamps, etc. pass through the frame and therefore the earthing fuse. As compared with a completely earthed system, such as utilised on our 20 H.P., the difference is that the emergency fuse, instead of being placed in the positive main, is placed on the negative side of the battery, and only includes those circuits which are through the frame. We suggest thatt the points in favour of such a system are :- | ||