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).
Testing procedures for a main switch, detailing electrical and mechanical test requirements.
| Identifier | ExFiles\Box 70\4\ scan0139 | |
| Date | 5th March 1928 | |
| Contd. -2- EFC4/T5.3.28. (5) The coil of the main switch shall be connected to the terminals of a six-volt battery, through an ammeter, and the amperes taken by the coils (with non-inductive resistance in parallel) at 6 volts at atmospheric temperature, shall lie within the limits 2.20 and 2.40 amperes. (6) Verify that the main spring tension (combined rating and set) is such that a current of not more than 1.6 amperes through the coil and non-inductive resistance in parallel is necessary to pull the switch arm over from the "off" position. (7) 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 to it. (8) While still warm from test (7), an alternating voltage of 205 shall be applied, through a light fuse, between the windings (including the non-inductive resistance coil) and the base; and also between the main switch contact pillar and the base; mxxxxxxm for one minute without breakdown. (9) The final test of the main switch is to consist of the testing under approximate working conditions as described in Section III. Contd. | ||