Fault diagnosis table for a C.A.V. regulator, detailing the effects with and without an armature fuse.
| Identifier | ExFiles\Box 166\7\ img084 | |
| Date | 13th November 1937 | |
| THE EFFECT OF THE ARMATURE FUSE - C.A.V. REGULATOR. Table columns are: Type of Fault, Effect with an Armature Fuse, Effect without an Armature Fuse. Failure of Second Stage of Regulator: [With Fuse] Armature fuse blows first, followed by overheating of regulator and eventual blowing of field fuse. [Without Fuse] For a period, heavy currents flow in the charging cables and switchbox contacts. When 90 amp. fuse blows, conditions become as in previous column. [Handwritten note: 15 amps more = R.L.6]. Cutout sticks when engine stops: [With Fuse] Armature fuse blows. [Without Fuse] An excessive reverse current discharges the battery and damages the dynamo. An earth on the field coils or connections: [With Fuse] The dynamo is quite uncontrolled and the armature fuse blows, protecting the external circuits. [Without Fuse] The dynamo voltage may reach about 90, and overheat or damage a number of parts of the electrical system. An earth on the Cutout: [With Fuse] Armature fuse blows. Car continues to run. [Without Fuse] 90 amp. fuse blows. Car stops. An earth on the Switchbox and Connections. (If the 90 amp. fuse holds): [With Fuse] Armature fuse blows and isolates dynamo. [Without Fuse] Dynamo overheats to provide fault current. | ||
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).