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).
Inspection and testing procedures for the 20 HP Switchbox.
| Identifier | ExFiles\Box 56\4\ Scan130 | |
| Date | 19th October 1926 | |
| X5730 19.10.26. X.5781sb.{Mr Bull/Mr Bannister} R.R. 20 HP. SWITCHBOX. X.5730. (1) Inspect the following points :- (a) The switch motion for correct operation as judged by the sensation of operating the switches. (b) Similarly, the operation of the gauge light press button. (c) The correct fit of the inspection lamp plug in its socket. (d) The locking mechanism for correct operation. (2) The insulation of the various switch contacts from the case of the switchbox shall now be tested by applying an alternating voltage of 200, through a low c.p. lamp, between the case and each terminal in turn, both switches meanwhile being in their "off" positions. (3) Now test the correctness of the switching operations as follows :- (a) First connect terminal No.6 to the positive of a 12 volt battery, and connect one terminal of a 12 volt lamp (preferably a large c.p. O.M.F. lamp taking 4 amperes) to the negative end of the battery. The wire from the other terminal of the lamp is used to touch successively on the various distributing terminals Nos.1 2, 3, 4 and 5, and it shall be verified in this manner that no light is obtained on these terminals with the switches in the 'off' position, but that :- (1) With S and T switched on, light is obtained from terminal No.5 only. (2) With HS{Lord Ernest Hives - Chair} and T switched on, light is obtained from terminals Nos. 4 and 5. (3) With I only switched on, light is obtained from terminal No.3 only. (4) With I and C switched on, light is obtained from terminals Nos.1, 2, and 3. --- | ||