First Solar Fused Combiner Box w/Wiring Harness 10 Wires w/MC3 Connectors
The outdoor rated plastic box has dimensions of 15 X 17 X 6 inches. Installed in the box is a DIN rail with 11 fuse holders made by Ferraz Shawmut model ULTRASAFE. The ratings for each fuse holder is 800 volt, 30 amp UL and 690 volt, 32 amp IEC. One fuse holder contains a fast acting fuse (KLKD 20) rated at 20 amps for up to 600 volts DC or AC. Ten fuse holders contain a 2 amp fuse type KLKD 2 also rated for 600 volts DC or AC. Attached to the fuse holder with the 20 amp fuse is the 'common' wire that goes to ten solar panel 'strings'. Attached to the fuse holders with the 2 amp fuse is an individual wire (labeled #1 thru #10) which goes to the positive side of the ten solar panel 'strings'. The wire that is used for all connections is 12 AWG type RHW-2 or USE-2 rated for 600 volts. Type RHW-2 and USE-2 is the designation for cable that is exposed to sunlight and does not fall apart from the UV affects of the sun. This combiner box and wiring harness is intended to use the First Solar panels in ten groups or 'strings' consisting of 5 panels each. 5 panels are normally connected in series with each other and this is accomplished easily by simply plugging the positive and negative MC3 connectors on the solar panels into the matching connectors on the combiner box wiring. Each First Solar panel can produce (under standard test conditions) 72.5 watts which is developed when the solar panel produces 1.07 amps at 67.75 volts. These numbers are normally called the Maximum Power Point amps (MPP amp) and Maximum Power Point volts (MPP volts). Grid tie inverters work most efficiently at a voltage input between 300 and 500 volts. The five First Solar panels connected in series produce about 338 volts.