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 and observations on a C.A.V. cutout device under cold and hot conditions.
| Identifier | WestWitteringFiles\F\May1921\ Scan50 | |
| Date | 18th May 1921 | |
| To R & E.{Mr Elliott - Chief Engineer} from EFC. c. to CJ. & FN. c. to Da.{Bernard Day - Chassis Design} & KP. c. to En. & By.{R.W. Bailey - Chief Engineer} c. EWT. for R.R.Inc. X.1610 - C.A.V. CUTOUT. With reference to the new sample C.A.V. cutout, recently sent down to you for your observation, we found this cutout to be quite decently definite in operation. As received from the makers it did not quite comply with our specification so was readjusted, after which the results obtained cold were quite O.K. In the cold condition we found the cutout to be definitely operated by the application of 12.4 volts .155 amp. to its shunt coil terminals. Deoperation on the shunt coil only (battery disconnected) occurred at 11.1 volts .14 amp. Deoperation with battery connected occurred at 12.1 volts .15 amp. and 1.7 reverse amperes from the battery. In the hot condition the cutout was operated at 14.4 volts .15 amp. on its shunt coil terminals and deoperated at 13.5 volts .145 amp. (battery disconnected). Deoperation with the battery connected occurred at 13.4 volts .145 amp. and .8 amp. reverse current. The usual tendency of cutout makers seems to be to adjust the cutouts to operate rather later than we feel is correct. We think that if the cutout in the cold condition operates between the limits 12.2 and 12.8, the rise of operating voltage due to increase of temperature, will be quite sufficient Contd. | ||