I was just reading that as you posted. Thanks. Yes, that is 100F. If you could laid out the heatsink and casing flat it measure 42"x17" of cooling surface. The drivers have over temp. protection. I'm thinking these are just underdriven to prevent them from heat issues.
Look ...
I'm not aware of the exact type of arrays used ...
I mean ,lately in Asian market ,there are so many led arrays....
(with almost 99.99% of them made from Brigededelloux Oiriginal chips ,originating of course ,
from a mysterious place,somewhere in Ca,USA ,that exports some thousands of tons of led chips ( every month ) ,
trying to cover the needs of the Asian Led manufacturers ...Anyway ...
Those four arrays can't be more than 50 W each.
So,most probably they 've a Vf or 32-35 VDC and If of 1400mA max ....
And those four are not connected in series ...
(Then total Vf would have been ~ 128-140 V ) ...
Worst case they are all connected parallel .....
( Same vf each ,string , Io max / 4 = 2.65 /4 = 0,660 ...
660 mA ...Way underdriven than the arrays max of 1400mA ..
actual power dissipation of each array ,ain't 50W but more like 23,2 W ..
If one fails ...
Then the rest three will run at 0.833 A
At ~ 31 Watt ..
If one more fails ...
Then the rest two are close to their spec max ...
If one of them fails,it drags the other along ,towards the silicone heaven ...
There's another type of lower wattage somewhat that operates at 9.5-10.5 V ...
And max If of 3500mA ...
Those can actually be connected in series ....
Say 4x10=40 V ...
And they run at 2.65 ...
That case sounds more possible ...
But actual power of each array is not 50 W ,but more like 10.5x 2.65 = 27.8 W (at best case ) ...