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 report detailing starter motor resistance estimation at various loads for a G2 motor.
| Identifier | ExFiles\Box 64\1\ scan0282 | |
| Date | 7th September 1928 | |
| STARTER MOTOR RESISTANCE ESTIMATION AT VARIOUS LOADS. Date:- 7 Sept 1928 Motor:- G2 Back E.M.F. / speed = .01184 torque / current Table Data: Current (amperes) (C), Conductor torque (lb-ins.) (Ts), Back E.M.F. / speed, Speed on brake (R.P.M.) (N), Back E.M.F. (volts) (e), Impressed P.D. (volts) (E), Ohmic volt loss, Motor resistance (ohms). 20, —, —, —, —, —, 11.60, —, — 30, —, —, —, —, —, 11.40, —, — 40, 15.7, .004645, 2240, 10.41, 11.20, 0.79, .01975 50, 21.0, .00497, 2000, 9.94, 11.00, 1.06, .0212 60, 26.3, .00519, 1825, 9.47, 10.80, 1.33, .0222 80, 37.0, .00548, 1520, 8.33, 10.40, 2.07, .0259 100, 48.2, .00571, 1290, 7.365, 10.00, 2.635, .02635 120, 60.0, .00592, 1085, 6.425, 9.60, 3.175, .0264 140, 71.7, .00607, 900, 5.46, 9.20, 3.74, .0267 (Handwritten annotation next to last 3 resistance values: .0266) 160, 84.0, .00622, 710, 4.43, 8.80, 4.37, .0273 180, 96.5, .00635, 535, 3.39, 8.40, 5.01, .0281 200, 109.0, .00646, 380, 2.45, 8.00, 5.55, .0277 220, —, —, —, —, —, 7.60, —, — 240, —, —, —, —, —, 7.20, —, — 260, —, —, —, —, —, 6.80, —, — Direct observations of resistances at 20°C. Field winding = .0138 ohm. } .0217 ohm Armature " = .0079 ohm. } Total motor resistance at 200 amperes = .027 ohm. Brushes 2° advanced. 7.9.26. EFG. | ||