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).
Specification of test for a 20/25 switchbox.
| Identifier | ExFiles\Box 166\3\ img002 | |
| Date | 16th October 1931 | |
| X.6069. SPECIFICATION OF TEST FOR 20/25 SWITCHBOX. X.6087. X.6016. Type :- Two-rate charge. Pull output with side and tail lamps on. Armature circuit broken before field circuit. (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, with the exception of terminal N (or central terminal); both switches meanwhile being in their "off" positions. Afterwards between the case and terminal N (or central terminal) with the right hand switch in each of the I and I & C 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) 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, 5 and R, 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 :- | ||