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).
Letter from the American branch to the UK branch detailing generator testing procedures and amperage settings.
| Identifier | ExFiles\Box 60\4\ Scan014 | |
| Date | 26th January 1931 | |
| X6099. ROLLS-ROYCE OF AMERICA, INC. SPRINGFIELD, MASS. EFC Btn-2 January 26, 1931. [STAMP: RECEIVED FEB 16] [STAMP: RECEIVED FEB 16] [STAMP: P.C.D RECEIVED FEB 5 1931] Rolls Royce, LTD., Derby, England. Attention: Mr. Hives Dear Mr. Hives: Re: Generator Testing [Handwritten: X.6099.] Generators are run about 1 1/2-2 hours under load and then while still warm, brushes are reset to 25 volts maximum and output curves taken. SK-415 shows the readings for three late generators at this stage. The brushes are then reset to 15 amps. hot and in this condition they are put on the chassis. [Handwritten: ? amperes] When cold every generator must give a maximum of 32 amps. with maximum brush setting - this is to assure that the full output is available. I enclose also print A-12982 showing full range of adjustment. Note that we: (a) Test at 25 amps. maximum when hot. (b) Set for chassis at 15 maximum when hot. (c) Check maximum (maximum adjustment) - 32 amps. when cold. The normal running load we figure are; Ignition - 5 amps. Lamps - 10 amps. and this should be taken care of by a 15 amp. setting. If, however, excessive night running is done, or short runs in cold weather, or extra fittings such as heater fan, searchlight, and screen wiper, a higher setting up to 25 amps. may be used to suit the circumstances and keep the battery properly charged. Yours truly, [Signature] RBB/VB Encl.2 | ||