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 results for sustained voltage, breakdown voltage, and ozone on a sample.
| Identifier | ExFiles\Box 165\1\ img016 | |
| Date | 13th May 1937 guessed | |
| Sustained Voltage Test. A sample was immersed in water and then 20 KV. (r.m.s.) 50 cycles was applied between the conductors and the water. (Minimum permissible time for failure, 5 minutes). Time for failure > 5 mins. Breakdown Voltage Test. A two yard sample was placed in water and connected to an induction coil capable of giving 120 KV., allowing sufficient length above the water to prevent flashover. The voltage was controlled by an adjustable sphere gap. The spheres were steadily separated at 15 KV/sec. until breakdown took place. The cable should have a breakdown voltage peak of at least 80 KV. Results obtained BDV. 99 KV. 95 " } Average 97.5 KV. Ozone Test. A sample of the cable was wound on an 1/8" diam. brass rod, 6 turns per 30", and the whole inserted in a glass tube 3/4" internal diameter. The assembled, but open tube, was stood in a current of air at a relative humidity of 60% for 3 minutes, and then the ends were tightly plugged. The cable was subjected to 20 KV. 50 cycles, applied between the conductor and the brass rod. (The time for failure must not be less than 8 minutes). Time for failure 1). 5 min. 14 secs. 2). 6 " 7 " [Upside down text at bottom] THE GENERAL CABLE RESEARCH LABORATORIES BIRMINGHAM 1a' ENGLAND FORM No: R231/30A | ||