Series Fuse Rating Solar Panels

As i read it a 15 a dc breaker would be safe and the minimum size would be 6 a 3 75 x 1 56 and rounded up.

Series fuse rating solar panels.

Commercially made solar panels over 50 watts have 10 gauge wires capable of handling up to 30 amps of current flow. This means each seriesneeds a fuse breaker placed in the combiner box as shown here. For example if you have four 100w panels connected in series each producing 20 volts and 5 amps the total output would be 80 volts and 5 amps. Now in the case of 3 panels in series and 4 strings in parallel if one string shorts the max amperage to short is 39 12 which exceeds the 30 amp max current rating of the 10 awg wire.

Thus if the modules used in this system had 15a series fuse ratings then the ocpds placed in the combiner box could be either 14a or 15a. In this case the battery wires and ac dc inverter will be safely disabled by the fuse. In 690 9 c the standard values for ocpds used in pv source circuits shall be considered in 1a increments up to 15a. Fusing solar panel arrays wired in parallel.

If each module s short circuit current is 4 2 amps then you could parallel 3 modules. Mnepv breakers are available in a 6 a rating and that size breaker should not be subject to nuisance tripping. We then take the total amperage and multiply it by a safety factor of 25 5a x 1 25 giving us the fuse rating of 6 25a or 10a if we round up. If you connect these panels in series there will be no increase in current flow so fusing is not required for this string.