GLASHAUS POWER - A good Inverter Combiner Box should have a high temperature rating, typically around 60°C to 85°C. All electrical connections generate heat due to I²R losses—the power dissipated is proportional to the current squared times the resistance. The question. ikes caused by lightning or grid switching op-erations. Both conditions raise internal operating. The installation ambient temperature of the combiner box should be between -25℃ and +60℃, and the relative humidity should be between 0 and 95%. So the max wasn't excessive like yesterday at 150F. As you can see, the heat is still.