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).
Examination and electrical test report for sample cables.
| Identifier | ExFiles\Box 168b\2\ img278 | |
| Date | 15th April 1935 | |
| 16148 EJJ. From Hs{Lord Ernest Hives - Chair}/Wst. Hs{Lord Ernest Hives - Chair}/Wst.4/MA.15.4.35. EXAMINATION AND ELECTRICAL TEST OF SAMPLE CABLES. We have now examined and tested the sample cables labelled 1, 2 and 3 submitted to us for test under cover of your EJJ.8/MM.4.4.35. Our conclusions can be summarised as follows :- (1) Conductor examination. All three samples have been well tinned with no signs of corrosion due to sulphur effect from vulcanization of the dielectric. (2) External cotton braiding. The braiding on sample 2 is coarsely woven and insufficiently waxed for satisfactory working in conduits without the risk of fraying. Samples 1 and 3 are both closely woven with good wax finish, No.1 being slightly better than No.3. (3) Electrical breakdown test. All three samples were immersed in water for 24 hours and tested for breakdown at the conclusion whilst still immersed. Samples 1 and 3 all withstood 20,000 volts R.M.S. without breakdown. Sample 2 broke down at 17,600 R.M.S. on 7/.029 cable and 15,100 R.M.S. on 3/.036 cable. (4) Electrical leakage test. All three samples were tested for leakage on a D.C. voltage of 2000 after 24 hrs. immersion in water and were found to be satisfactory. | ||