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).
Procedure detailing the 'Load Test' (Test 2) for a motor.
| Identifier | ExFiles\Box 35\4\ scan 127 | |
| Date | 19th August 1922 guessed | |
| -3- Contd. TEST 2. LOAD TEST. The motor, loaded up by means of a brake, shall now be run from a 12 volt battery of ample capacity, the brake torque being adjusted until the current taken is 100± 1. amperes, and the motor run for 10 minutes with a current within these limits. During the last 5 minutes of the test the torque shall be 34 to 36 lb-inches and the speed must not be less than 125 times the motor terminal voltage, which shall be 10.0±.1 Until the motor has been made to pass the light test it should not be put on the load test, because it would be found that a motor taking excessive current on the light test, due to bad magnetic circuit, would also take an excessive current for a given torque, on the load test for the same reason, and conversely a motor which has passed the light test will not, as a rule, give a torque below the lower limit. On the load test, provided the motor has a sufficiently good magnetic circuit to pass the light test, the specification that the ratio of the speed to the terminal voltage must exceed a certain figure, ensures that the electric circuit is good, that is to say, that no undue amount of resistance is introduced in the shape of bad connections or brush contacts. Any such defects as these, by absorbing voltage will lower the speed of the motor, because, other things being the same, the speed is proportional to the voltage that remains when the voltage required to drive the current through all the ohmic | ||