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).
Investigation into the failure of cutouts in distribution boxes 83 and 717 due to open circuited shunt windings.
| Identifier | ExFiles\Box 47\4\ Scan236 | |
| Date | 8th September 1924 | |
| EFC. {E. Fowler Clarke - Electrical Engineer} AC.21. 8th Sept. 1924. CUTOUTS IN DISTRIBUTION BOXES 83 (Chassis 47-GO) AND 717 (Chassis GH.21). Both these cutouts, which were returned on account of failure, were found to have open circuited shunt windings. No.83, on being dismantled, was found to have the wire broken away from the metal tab, on which the last few (outside) turns are soldered together, and the connecting flex attached. There were signs of local burning, probably after the breakage had occurred, but none of corrosion. The remainder of the coil was sound. It is not very apparent how the wires should have become broken, unless by movements of the flex caused by repeated connection and disconnection at terminal B. No. 717 cutout. In this the wire was unbroken, but it was not soldered to the connection tab (outside) there being only a small spot of solder which had "taken" to the metal. On disturbing the connection, the circuit became completed. The cutouts are now in the lab. dismantled. RJA. | ||