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).
The fault and repair of a 20 HP Dynamo No. 21.
| Identifier | ExFiles\Box 47\4\ Scan221 | |
| Date | 15th September 1925 | |
| EFC. {E. Fowler Clarke - Electrical Engineer} absent. X. 4118 To NRC. {N. R. Chandler} from EFC. {E. Fowler Clarke - Electrical Engineer} (Repair Dept) EFC {E. Fowler Clarke - Electrical Engineer} /RJAL/T15.9.25. X.4383 - 20 HP. DYNAMO No.21. - F. {Mr Friese} SLATER. Herewith we return this machine which we think you will now find O.K. The fault was that the control brush holder was distorted from its axial alignment, which restricted free movement of the brush and so prevented proper excitation. When this was corrected, the machine functioned normally and passed the production test used for machines of this type with 29 commutator segments. Before the machine is again put into use, the control brush holder should be lowered to within not more than .090" of the commutator, as at its present distance, brush chattering may be set up at some future time and so cause de-excitation. EFC {E. Fowler Clarke - Electrical Engineer} /RJA. | ||