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).
Test results table for various Lucas cut-out devices under cold operating conditions.
| Identifier | ExFiles\Box 36\4\ scan 042 | |
| Date | 30th April 1920 | |
| X.3770. LUCAS CUT-OUT. X.1627. TEST TABLES. Cut-out number. | Cold condition Just operated at (volts, amperes) | Cold condition Just de-operated at (volts, Shunt amps, Series reverse amperes.) | Shunt Ohms. (cold) | Remarks. 19 | 12.45 | .27 | 12.45 | .265 | .1 | 46.2 | Passes. 29 | 9.8 | .225 | 11.7 | .27 | 4.4 | 43.4 | Cuts in too early and takes too much reverse current. 91 | 14.1 | .28 | 12.1 | .24 | 1.55 | 50.3 | Cuts in too late. 129 | 10.2 | .20 | 11.9 | .235 | 3.55 | 50.3 | As for 29. 14267 | 11.4 | .22 | 11.9 | .23 | 1.7 | 51.8 | Cuts in slightly too early. 15770 | 13.4 | .30 | 11.8 | .28 | 1.15 | 43.9 | Cuts in slightly too late. | ||