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).
Results of an electrical breakdown test on various grades of wire, with a recommendation for future use.
| Identifier | ExFiles\Box 69\2\ scan0018 | |
| Date | 18th September 1930 guessed | |
| -3- (5) Electrical breakdown test. The samples of wire were wound on to a 1" diameter metal bar and an A.C. 50~ voltage impressed between the conductor and the bar. Two samples of each grade were tested. McLeod - 360 and 480 volts Dudlo - 450 and 490 volts Prescot - 60 and 280 volts Concordia - 113 and 336 volts Connolly - 332 and 346 volts These results shew that the Prescot wire is very poor and if used on production would, we consider, contribute very largely to coil failure. The best wire all round we consider to be the Swiss sample handled by McLeods. Dudlos (U.S.A.) and Connollys (British) are very nearly as good, while Concordia would be improved considerably if the enamel insulating properties were better. We therefore recommend Connollys as the best British wire for use on our coil secondaries providing Mr. Brock can obtain uniformity of wire diameter". EFC. Copy of specification of test attached. | ||