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).
High tension D.C. testing of Redmanol coil cases at temperatures up to 100°C, proposing a specification for insulation tests.
| Identifier | ExFiles\Box 69\1\ scan0051 | |
| Date | 4th May 1927 | |
| X4077 Y8710 To R.{Sir Henry Royce} from EFC. c. BJ. PN.{Mr Northey} c.Wor.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} c. E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. Mr. Brock. EFCl/T4.5.27. HIGH TENSION D.C. TESTING OF REDMANOL COIL CASES AT TEMPERATURES UP TO 100°C. Y3173 X4079 In regard to our EFCl/T29.4.27, we now give the results of some tests taken on half a dozen redmanol coil cases of the type at present going on production, the apparatus used for this purpose being that as described in the aforementioned note. These results will be found in my assistant's report PC.132, copy of which is attached. On the basis of the results given in this report, a proposed form of Specification of Test for these coil cases is as follows :- "Specification of Insulation Test at Temperature of Redmanol Coil Cases. With the six-volt RR. trembler coil No. 6162 operating on a voltage of from 5.5. to 5.75 volts, and with the coil cases to be tested with the two electrodes in position (the inner electrode connected to the H.T. D.C. supply, and the outer to earth) placed in the oven. (1) With the supply switched on and the voltage measuring spark gap open so as to ensure that no sparks pass, and with no condenser connected external to the rectifying unit, the reading of the Weston galvanometer should be carefully noted, time being allowed to obtain a settled condition. (2) With the supply still on, the spark gap should be gradually closed until a breakover just occurs, when the supply may be switched off, the gap measured, and the equivalent voltage computed. (3) The ratio of the voltage so obtained to the reading of the galvanometer in microamperes should then, for an ambient temperature lying between the limits 15 to 25°C, not be less than that given in the following table :- Contd. | ||