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).
Testing procedure for a dynamo, including insulation resistance, main and final bedding of brushes, and output checks.
| Identifier | ExFiles\Box 70\4\ scan0056 | |
| Date | 19th May 1925 guessed | |
| -2- Contd. (2) The insulation resistance of the machine should be taken and should not be less than 1 megohm. N.B. For the running tests of the dynamo there must be no armature end play. It may be necessary to insert washers between the temporary driving pulley and the pulley end 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. (3) Main bedding of brushes. The dynamo shall now, starting cold, be run on load at about 950 r.p.m. charging a 12 volt battery of ample capacity and the condition of the brush bedding observed and improved from time to time, if necessary. This should continue until the working surface of each brush shows evidence of making contact across the whole thickness of the brush (i.e. in the direction of the commutator circumference at some place for an axial distance not less than .050"). (4) Final bedding of brushes. With end cover removed the dynamo shall now be run on load at 1050 r.p.m. for 3 1/2 hours charging a 12 volt battery of ample capacity. This should render the brush bedding finally satisfactory. (5) At the termination of the above run, and after a quick final examination and passing of the brush bedding and commutator condition, observations shall be made of the output of the machine at this same speed of 1050 r.p.m. which output should lie between 11.0 and 12.0 amperes, the terminal voltage being adjusted to 15.0 ±1. Contd. | ||