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).
Recommendation for a procedure to test the efficiency of electric motors to accurately measure power consumption.
| Identifier | ExFiles\Box 76\2\ scan0023 | |
| Date | 4th December 1911 | |
| Handwritten note (top left): Tech! Cttee. Let this be done C.J. but not so as to interfere with present difficulties which have to be overcome Handwritten note (top right): 28th meeting (6) Handwritten note (left margin): X632 Stamp (top left): E S = 11 = XII = Stamp (right): 11 | XII | 11 | D Bertolini's Palace Hotel, Naples. 4th Dec 1911 As I know our bill for power current is getting a formidable item, I recommend the following procedure- Every motor that is to be used in the works, and one of each type and size which is in the Works, shall be tested in the Engine Testing Dept. as follows:- The motor shall be coupled to the large continuous current dynamo, the efficiency of which we know, and tested at its full rated power and at the average load it usually carries. These two loads are important to us and the efficiency (all day) is the most important of all. The ingoing current should be read by electricity metre of exactly the same type as that used by the Corporation to make out our bill. The volts can be read by any correct reading voltmeter. If our old continuous current dynamo is unsuitable as a load, a water cooled pulley with rope dynamometer can be very easily arranged, and for this purpose, I think, may be considered best. It is quite different to testing petrol engines. F.H.R. Footer: R.R. 235. (20 H) 823 (W) (11.9.11) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1923 | ||