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).
Abstract of a translated paper by Dr. Bultemann on the properties and breakdown of electrical insulation.
| Identifier | ExFiles\Box 24\2\ Scan084 | |
| Date | 24th January 1921 | |
| X. 1109 (filed 24-1-21) X.1109 - INSULATION. (Abstract of Translation of Dr. Bultemann's Paper 9.12.1917). To investigate, find puncture voltage and leakage current, allowing dampness of air. For breakdown use transformer several K.W's. Test stand should consist of flat plates. Compress material well between these. High stresses for short time less harmful than the converse. No apparent relation between breakdown voltages and dielectric strength. Differences of commercial frequencies have no effect on breakdown voltage. Heating effect due to displacement current increases rapidly with current. Production of ozone and nitric oxides. Particles in suspension in a liquid move under influence of potential gradient. Increase of temp. of dielectric reduces breakdown voltage. Spec. ind. capacity has no influence on breakdown but alters potential gradient. Hence necessity for homogeneous insulating materials. High frequency alt. voltages cause greater heating. But losses in liquid insulators, independent of frequency. Energy loss increases with temperature. Contd. | ||