erickench
Senior Member
- Location
- Brooklyn, NY
There are two things about this NEC section that puzzles me. First, NEC 690.8(A)(1) states:
The maximum current shall be the sum of parallel module rated short-circuit currents multiplied by 125 percent.
Since when is maximum current higher than short circuit current? I would've thought that the nameplate current is the maximum current and the short circuit current would be higher.
Second, NEC 690.8(B)(1) states the following:
The circuit conductors and overcurrent devices shall be sized to carry not less than 125 percent of the maximum currents as calculated in 690.8(A).
If we were to assume that the maximum current is 125 percent of the so called short-circuit current(or nameplate current) then we would be applying the 125% factor twice in performing the calculation. Here's what I mean:
short-circuit current multiplied by 125% and then multiplied again by 125% to obtain the conductor ampacity and OCPD rating.
Has anyone ever seen the nameplate of a PV module? Does the nameplate designate it as a short-circuit or maximum current? Anyone?
The maximum current shall be the sum of parallel module rated short-circuit currents multiplied by 125 percent.
Since when is maximum current higher than short circuit current? I would've thought that the nameplate current is the maximum current and the short circuit current would be higher.
Second, NEC 690.8(B)(1) states the following:
The circuit conductors and overcurrent devices shall be sized to carry not less than 125 percent of the maximum currents as calculated in 690.8(A).
If we were to assume that the maximum current is 125 percent of the so called short-circuit current(or nameplate current) then we would be applying the 125% factor twice in performing the calculation. Here's what I mean:
short-circuit current multiplied by 125% and then multiplied again by 125% to obtain the conductor ampacity and OCPD rating.
Has anyone ever seen the nameplate of a PV module? Does the nameplate designate it as a short-circuit or maximum current? Anyone?
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