Early Spring we converted to a Jacuzzi Saniclear 40 salt system. The box that is on the house gets VERY hot. This morning when I turned it on it was fine...chlorine was a little low in the water so I switched it to super chlorinate. I came back out in a couple of hours to switch it back...the screen on the box was black. I switched it back and after about an hour the screen had reappeared. The sun is on the box from about 11 to 1. Even when it is in the shade the box is still very hot...is that normal?