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).
Switchbox contact life tests.
| Identifier | ExFiles\Box 65\2\ scan0012 | |
| Date | 7th November 1928 | |
| RR 238 (150 BKS.) (DB{Donald Bastow - Suspensions} 461-8-12-24) NP 3C6975 X7730. ROLLS-ROYCE LTD. INSTRUCTIONS. To: F.E.C. Order No.: AD 17. Customer's No.: X Switchbox Contact Life Tests. The first of these tests in which the field contact is broken first - and the cut-out shunt is connected to Terminal C of the distribution board has been completed. The switchbox, having a lag of about 8° or .07" in the blade movement between the breaking of the field and the armature contacts was connected to a 20 hp dynamo running at about 1500 rpm, and by means of a revolving crank and a wire was made to switch on and off at about 50 cycles per minute. The contacts failed after 12 1/2 hours running making 37500 operations: the field contact Signed: (Contd) This Sheet must be filed on completion of the work. | ||