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).
Test procedures for a main switch, specifying current, voltage, and pressure parameters.
| Identifier | ExFiles\Box 64\3\ scan0216 | |
| Date | 9th March 1926 guessed | |
| -3- Contd (5) Verify that the main spring tension (combined rating and set) is such that a current of not more than 1.5 amperes through the coil and non-inductive resistance in parallel is necessary to pull the switch arm over from the "off" position. (6) It must further be confirmed by means of a spring balance that the combined rating and set of the spring is such that this main switch is definitely capable of holding on contact with a copper contact pressure of at least 2.0 lbs., when a current of 3.0 amperes, inclusive of the current passing through the parallel non-inductive resistance, is supplied toit. (7) While still warm from test (6), an alternating voltage of 205 shall be applied, through a lamp, between the windings (including the non-inductive resistance coil) and the switch arm; and also between the main switch contact pillar and the switch arm; for one minute with-out breakdown. (8) The final test of the main switch is to consist of the testing under approximate working conditions as described in Section III. Contd. | ||