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 for modifying a Lucas improved switchbox for use with the temporary Lucas 'Goshawk' earthed electrical system.
| Identifier | ExFiles\Box 51\2\ Scan081 | |
| Date | 19th January 1922 | |
| X 4338 19.1.22. INSTRUCTIONS FOR MODIFICATIONS TO LUCAS IMPROVED SWITCHBOX WITH COMPOUND MAGNETIC CIRCUIT TO RENDER THIS SUITABLE FOR USE WITH THE TEMPORARY LUCAS 'GOSHAWK' EARTHED ELEC. SYSTEM. x3749 b x4338 x4349 (1) Remove the internal portion from the box. (2) It is necessary to remove two of the connecting bars from the back of the base-plate:- (a) The bar connecting the top element of the four-point dynamo switch to the extreme right hand terminal near the field fuse (right and left hand being used when looking upon the front of the switch-box). The top element of this four-point switch will not be connected to anything, therefore the nut may be replaced with a suitable washer. The terminal which has been disconnected therefrom will, with the modification, be an earthing terminal for the earthed side of the inspection lamp plug socket and the earthed end of the shunt coil of the cutout. (b) The link connecting the two positive terminals of the switchbox to the right hand pillar of the inspection lamp plug socket. A short link should then be made to reconnect these two terminals, and a further short link, which may be a wire link, to connect these again to the top (tall) left hand terminal nearest the switch, i.e. the terminal connected to the insulated contact of the cutout. (If there is, as in the first few switchboxes, a wire link through a sisterflex tube connecting this terminal through the lighting switches at the top, this connection can be lengthened and attached to the middle (bottom) left hand terminal, this connection being the same electrically but more even on account of avoiding the depth of three connections at the point at which it was previously). The three terminals which are now connected together will serve as a positive distributing point - see diagram of system. To complete the modifications a connection should then be made between the right hand pillar of the inspection lamp plug socket and the earthing terminal left free by (a), replacing on this connection the free end of the shunt winding of the cutout. The switchbox should then be right for the Lucas Goshawk temporary system in accordance with our diagram. EFC. {E. Fowler Clarke - Electrical Engineer} | ||