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).
Specification for the running test of a 20/25 HP dynamo.
| Identifier | ExFiles\Box 60\2\ Scan019 | |
| Date | 12th May 1931 | |
| SPECIFICATION OF RUNNING TEST OF 20/25 HP. DYNAMO. Armature :- 28 slot 16 conductors. Brush angles:- 15° 121° Poles :- .015 air gap and trailed. The machine is assumed to have all mechanical adjustments correct and brushes approximately bedded. (1) In order to get the brushes finally bedded and the commutator surface with its working skin formed, the machine should be run with end cover removed for 3 1/2 hours at 2,100 R.P.M. with a terminal voltage between 16 and 17. (2) At the end of the above run, with the voltage adjusted to 16.5 +- .1 the output of the machine should fall within the limits 10.5 to 12.0 amperes. (3) With the dynamo still hot it should show an open circuit voltage of 14.0 at not more than 900 R.P.M. (4) Now run the machine at varying speeds up to 4000 R.P.M. and observe that noise, brush sparking and mechanical balance are reasonable. Afterwards confirm the condition of the machine by a general inspection. (5) Apply an alternating voltage of 200 through a low c.p. lamp between terminals and case and confirm that no failure of the insulation occurs. He/CAP. | ||