My Travel Power 220 v AV 17A alternator keeps failing. If started from cold it will run (i.e. produce an indicated 220 v) for about 15-20 minutes, this regardless of whether it is totally without load or with a moderate (1 to 2 kW) load. Then the voltage fluctuates for a minute or so before dropping to zero. The green light is (usually, but not always) on when the voltage is at 220, off when not; the red light is never seen.
If it is switched on when the engine is hot (so the alternator has been turning but not generating power for several hours) it lasts considerably less time - only 2 to 3 minutes.
It until is almost 12 years old, and has been used mostly on a very light load, with very occasional brief periods of moderate or high load. The engine has recorded a little over 8,000 hours.
The fan within the power box runs while it is producing voltage, but is stopped when it is not.
The alternator drive belt is in good condition and correctly tensioned and the alternator definitely continues to turn when it has failed to produce power.
Can anyone give me a clue of where to go from here?
Many thanks all.
Rob H