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).
Tests conducted on S.U. Electric Petrol Pumps to investigate a reported delivery fault.
| Identifier | ExFiles\Box 163\1\ img003 | |
| Date | 11th September 1933 | |
| x6007 From Hs{Lord Ernest Hives - Chair}/Wst. C. to By Hs{Lord Ernest Hives - Chair}/Wst.1/MA.11.9.33. S.U. ELECTRIC PETROL PUMPS. GWH.{George W. Hancock - Head Chateauroux} reported that when these pumps were wired by taking one common feed to one pump and looping in the second pump from the first there was a different delivery of petrol in Pts/hr., than when each pump was fed independently from a common course. As we were unable to explain this we carried out careful tests with two pumps with the wiring arranged in different ways. We found that we couldn't reproduce the fault and that we got the same delivery for the same pump temperature which everway the pumps were connected. We found however that the temperature of the pumps made all the difference to the delivery, and this may have caused GWH.{George W. Hancock - Head Chateauroux} to obtain the different readings, the pumps being at different temperatures when he took the readings. At the same time we took careful measurements of the current taken by these pumps when running free and when pumping for a maximum head, and we give below a table giving the results we have obtained :- Temp. oC. pump body. | Delivery Pts/Hr. | Volts. (Running Free.) | AMPS. (Running Free) | Volts. (When Pumping.) | Amps. (When Pumping.) ---|---|---|---|---|--- 22 | 136 | 11.9 | 2.5 | | 25 | 126 | 11.75 | 2.45 | | 30 | 120 | 11.75 | 2.42 | | 35 | 120 | 11.72 | 2.3 | 11.75 | 2.8 38 | 118 | 11.75 | 2.25 | 11.75 | 2.85 40 | 115 | 11.75 | 2.25 | 11.75 | 2.9 | ||