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).
Redesign of an accessory distribution board to include an earth terminal.
| Identifier | WestWitteringFiles\T\January1929-February1929\ Scan078 | |
| Date | 28th January 1929 | |
| FROM E.{Mr Elliott - Chief Engineer} C. to HS.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} EPG. SECRET. E3/M28.1.29. X7741 ? ACCESSORY DISTRIBUTION BOARD WITH EARTH TERMINAL. Owing to the difficulty of obtaining single pole body light fittings etc. and also the danger of relying on coachbuilders for establishing reliable earths it was agreed to use double pole wiring for accessories, and provide an earth terminal for same somewhere on the dashboard. The most suitable place without doubt is the accessory distribution board itself, and we have been able to re-arrange this to include the earth terminal and at the same time make the base and cover shorter and more compact than before. We attach herewith blueprint of LeC. 2652. shewing the proposed design. Economy in space has been effected by using a common base plate for the upper fuse posts on the face of the board for carrying the present fuse guides. This dispenses with two bolted connections and leaves room for the POSITIVE battery cable and insulated fixing to dash at top of board. The NEGATIVE terminal is arranged as an extension of the dash fixing at the bottom of the board with enlarged cable ports each side to accommodate twin wires from the various accessories. Any shorting across the positive and negative terminals at the bottom of the board will only at the worst blow one of the fuses. As before this distribution board should be mounted on a sub-base on the wiring conduit. E.{Mr Elliott - Chief Engineer} | ||