I was confused by your talk about the voltage yesterday because one of the early things I learnt is that voltage requirement drops when you run a board at lower current. This I learned from LED Gardener - he runs a demo in one of his vids with a multi meter and a constant current that shows how voltage drops when lower current goes to the board.
Exactly why my first guesstimate was lower than the actual wattage you supplied.
You ARE putting 50V into each board @ 0,7A, or else there's something wrong with the watt meter, or the driver is putting out more current than stated in its specs.
If you pull 186w from the wall, the boards get: 186w AC * 0,94% driver efficiency = 174,84w DC
175w DC / 5 boards = 35w DC per board
35w DC / 0,7A = 50V per board
Now we've established that you can put a max of 50V and 0,7A (or 35w DC) into each board with the driver you have.
Or if we assume the boards run at 48V the driver MUST put out 0,729 A, this is certainly plausible, but I would definitely put more eggs in Meanwell's spec basket than in that of an unknown board with changing max ratings.
Apparently I could run them as crazily high as 1600ma with really good heatsinks
Max rating has NOTHING to do with heatsink, this is very important to understand.
Again, the producer is obviously not giving you the actual
electrical max rating, but giving you a guideline on how to run them.
The max current is fixed, it never changes, and going above it will fry the unit regardless of heatsink/cooling.
The maths just don't add up, so there's a false part somewhere in the eqaution that much is sure, it could be me, I might have calculated it wrong and missed my mistake on the second and third check, but I trust my calculations when they're checked thrice almost as much as I trust Meanwell's HLG drivers.
Now we're down to the board or the watt meter and so far there hasn't been conflicting specs out on the watt meter, so using logical abduction the board is most likely the false part in the eqaution
Look at HLG's QB120 they have 120 diodes and can supposedly be run above 65w DC without heatsink.
Max rating: 24,4V and 2,8A.