Tune to P5 Pannel blowing fuses

[Croydon Lights]

I need some help with my Tune to P5 panel that keeps on blowing fuses after a couple of hours running
The pannel is made up off 3 x 4 outdoor P5 panels with a 7.5 amp fuses providing power to each two panels
There is no vent for heat to escape or circulation, could this be cause of the problem ?

 

[AAH]

The current for 2 P5 panels is potentially over the 7.5A rating of the fuses depending on the panel brightness. If there is a gradual buildup of heat then the fuse trip current will decrease. For a 30 degree temperature rise there will be a drop in the capacity of about 5%. If you're running at higher than the rated current of the fuse then the trip curve also comes into play.
I'd drop a fuse out and put a multimeter across the fuse terminals on the current range and have a look at what current you are actually drawing while displaying stuff.