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).
Electrical tests of Aero H.T. ignition cable sleeves made from different moulding powders.
| Identifier | ExFiles\Box 61\1\ scan0160 | |
| Date | 6th March 1931 | |
| X6011 Hy.{Tom Haldenby - Plant Engineer} from EFC. c. Sft{Mr Swift}/Mr.Brock. EFC2/ADL6.3.31. X.6102. AERO H.T. IGNITION CABLE SLEEVES. X.6011. The following is a copy of my assistant's report WE.86 on some H.T. insulating sleeves E.21468 made from various moulding powders :- "We have carried out electrical tests, as specified on the drawing, on six insulating sleeves E.21468 moulded in various materials, two in Redmanol, two in British Dyestuffs powder grade AL.228/31 and two in Stokes powder. The tests consisted of immersing the sleeves in water at atmospheric temperature for 24 hours, wiping dry and then ascertaining the flash over voltage. The following figures were obtained :- Redmanol.............. 17,000 volts R.M.S. B.D.C................... 17,400 volts R.M.S. Stokes.................. 13,500 volts R.M.S. As the minimum specified voltage is 15,000 R.M.S. it will be seen that the Stokes sample is unsuitable. It was also noticed that whereas the Redmanol and B.D.C. sleeves did not track with a single flash over, the Stokes did. It appears, therefore, that the Stokes powder has greater tracking proclivities." EFC. | ||