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).
60-hour volt-drop test of a switchbox, detailing failure, adjustments, and measurements.
| Identifier | ExFiles\Box 65\2\ scan0210 | |
| Date | 1st December 1924 | |
| ROLLS-ROYCE LTD. INSTRUCTIONS. To.......................................................19 Order No...................................... Customer's No. 2 totalled 60 hours while the number of switching operations was 28,618 after which the field contact in the switchbox failed. Each day a volt-drop test across the cutout from terminal A to earth was made after reaching final temperature. The volt drop measurement for 12 amperes gradually rose from .269 to .290 when about 20 hours continuous running and 7000 switching operations had been completed. It was found that the points were not making perfect line contact and accordingly they were carefully trimmed and readjusted and checked by watching the sparking until perfect line contact was secured. The volt drop measurement then obtained was .271 v.{VIENNA} the value undulated slightly from day to day and (Contd) Signed This Sheet must be filed on completion of the work. Top left header: RR 238 (150 BKS.) (OB 461-B-12-24) MP 306975 | ||