In most cases, no, as long as there is a DC disconnecting means at or in the inverter.I plan on installing a combiner box to combine 5 strings into 1 than runs to the inverter. Is a disconnect required?
A touch safe fuse holder disconnects the fuse from both directions.But if the combiner box fuses the strings, wouldn't a disconnect be required per 690.16(A)?
A touch safe fuse holder disconnects the fuse from both directions.
In my installation it goes from service - meter - disco - sub panel - inverter (inside building) - combiner box (maybe combiner/disco) - array. The AHJ said a disco wasn't needed, hence my confusion.
The code does not specify that the fuse isolating disconnecting means must be load break rated. If you have a load break rated DC disco in or at the inverter and touch safe fuse holders in the DC combiner, in most situations that is all you need. If the DC goes inside a building, then other rules may apply.But most of the time cannot not serve as a load-breaking disconnect for DC.
Therefore use depends on what the purpose of the disconnect is seen to be.
If the DC goes inside a building, then other rules may apply.
So after watching Mike Holt's dvd on solar, I think that not only do I need a combiner/disconnect, but it has to be fused as well. Am I seeing this install clearly?
Any time you have more then two strings in parallel, you need one OCPD per string at or below the maximum series fuse value listed for the panel. The easiest way to furnish this is to use a combiner containing either fuses or CBs.
Or does 690.9 (A) exception apply? An overcurrent device shall not be required for PV modules or PV source circuit conductors sized in accordance with 690.8(B) where one of the following appliesb) the short-circuit currents from all sources do not exceed the ampacity of the conductors or the maximum overcurrent protective device size specified on the PV module template
So I guess the question I have now is does the output current from the combiner to the inverter need to be fused? I will be combining 6 strings, 7.9 Isc, which equals 73.9 amp. That 73.9 amp load is where I am having confusion.
The code says that the conductors from the combiner to the inverter need to be protected.