DC Solar Combiner Box
The purpose of the Solar combiner box is simple, to amalgamate all the separate PV strings into one voltage to enter the inverter sections. While that is the basic function there is a lot more then meets the eye that needs to be provisioned for. Over current and over voltage protection must also be provided. In the combining you may end up with several series units in parallel with one another. Back feeding higher output devices cannot be allowed to push power into weaker performing units and destroy the PV cell. There for rectifiers may be installed to prohibit this. Some PV combiners also have active current monitoring to maximize output production and help when diagnosing issues in string sets.
Combiner boxes are often used strategically through the PV field close to the cells to combine PV groups close together and reduce wire required by stepping voltage up early. These smaller string boxes will then feed larger combiner boxes, and so on. Smaller string boxes and combiner boxes are generally NEMA-4 as they are directly exposed to the outdoor elements. Larger combiner panels are generally rated NEMA-3R for our door, and NEMA-1 or 11 for indoor housed units.
The combiner box as minimum generally has per string fusing and over voltage shunt protector. More elaborate units will have chopping transistors and circuit breakers, along with DC LEM style current and voltage monitors.
Solutions Controls can provide from the simple small string box to the fully automated DC Combiner box as you needs dictate. Many options that are required are disconnect and isolation switches, remote monitoring equipment, and ESD (Emergency Shutdown) provisions.
We will only use quality properly matched products that are rated to perform the duties as your application requires.