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 procedures for an intermittent load test and inspection notes for motor commutators and brushes.
| Identifier | ExFiles\Box 35\4\ scan 129 | |
| Date | 19th August 1922 | |
| TEST 3. -5- 19.8.22. INTERMITTENT LOAD TEST. (This test will consist of switching the motor on and off intermittently under load (about 10 secs. on and 10 secs. off) for a period of 3 minutes). During the test the motor should be observed for satisfactory general starting and running (in particular the commutator and brushes should be watched). NOTES RE TESTS 1, 2 & 3. (a) Before, between and after the light and load tests, the commutator and brushes should be carefully examined. The commutator should be found to be free from grease or varnish; this latter is difficult to detect when the motor is hot. The contact surface of the brushes should be examined after the light test to see that there is sufficient area of contact, which we consider should exceed 80% of the total. Running the light test on the motor considerably improves the bedding of the brushes for the load test. (b) Brushes should a-gain be carefully inspected for freedom in the holders without excessive clearance. (c) A very good test for each brush consists in, on the load test, lifting off the companion brush opposite to itself, under which circumstances the brush under test has to carry the full current. If it does this without shewing signs of distress, which are indicated by jumping of the ammeter needle, it may be depended upon to be quite satisfactory when working in conjunction with it-s companion brush, provided Contd. | ||