OK 500Watts is 2A hot, more like 10-20A inruch when cold, so 10 - 20 ohms per lamp cold. Even one is very much off the bottom of the meg ohms range. A contimuity meter with a low ohms range might see it more accurately.
Now 42 posts of 2 lamps is 84 lamps, so expect between 10 ohms/84 to 20 ohms/84 . That will probably look like a short even to the continuity meter.
We expect all phases and N to be almost shorted to all but the highest test current lowest ohms range.
So The oddone out is E - we do not expect either L or N to short to E !!
But it works without blowing anything, so L-E short is not present.
My money is on an N-E fault.
Genset will not see that, but somewhere -perhaps a pinched cable in a lampholder, or at the base of the pole or underground cable spiked.
Divide and conquer ( make an all cores break in the centre - expect N-E fault in only left or only right side only. Divide faulty half in to to quarters etc.) until it is one or two poles or the link between them,
OK 500Watts is 2A hot, more like 10-20A inruch when cold, so 10 - 20 ohms per lamp cold. Even one is very much off the bottom of the meg ohms range. A contimuity meter with a low ohms range might see it more accurately.
Now 42 posts of 2 lamps is 84 lamps, so expect between 10 ohms/84 to 20 ohms/84 . That will probably look like a short even to the continuity meter.
We expect all phases and N to be almost shorted to all but the highest test current lowest ohms range.
So The oddone out is E - we do not expect either L or N to short to E !!
But it works without blowing anything, so L-E short is not present.
My money is on an N-E fault.
Genset will not see that, but somewhere -perhaps a pinched cable in a lampholder, or at the base of the pole or underground cable spiked.
Divide and conquer ( make an all cores break in the centre - expect N-E fault in only left or only right side only. Divide faulty half in to to quarters etc.) until it is one or two poles or the link between them,
