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).
Instructions for testing springs, brushes, and the insulation resistance of a machine.
| Identifier | ExFiles\Box 168a\3\ img264 | |
| Date | 7th January 1930 guessed | |
| -2- Test the springs for cracks, by forcing these back as far as possible, when they should not become cracked. Note (1) It is possible that a spring which is noticeably weak is cracked and requires replacing. Note (2) It will usually be found that a spring which is good has a uniformly expanding spiral. (e) The connections of the pigtail connectors are not in any way damaged. (f) The initial bedding of the brush shows partial contact reasonably well distributed over the working surface. (Preliminary bedding of brushes). (2) The insulation resistance of the machine should be taken and should not be less than 1 megohm. N.B. (a) For the running tests it will be necessary to insert a variable resistance in the field circuit of the dynamo. This should be connected between the field terminal and the negative (earthed) brush. A second variable (carbon) resistance is used in the main circuit with which to adjust the terminal volts. (b) Where there is armature end-play, it may be necessary to insert washers, between the temporary driving pulley, and bearing so as to keep the armature up towards this bearing, i.e. in the position which it will have when fitted on the chassis. A | ||