Is it exposed to sunlight?

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sketchy

Senior Member
Location
MN
If I install EMT on the racking of a roof mounted solar array, UNDER the PV modules, is this considered to be exposed to sunlight?
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Do the PV modules have quick disconnect cables to allow them to be removed for servicing or is it a high voltage DC string?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
If I install EMT on the racking of a roof mounted solar array, UNDER the PV modules, is this considered to be exposed to sunlight?

Exposed to sunlight in NEC usually refers to the conductors or the jacket, regarding UV damage, so for that part with EMT it does not matter.
If you are looking at temperature derating factors for conductors in EMT on a roof, the part of the EMT totally shaded by the array would not be exposed to the temperatures listed for that same distance above a roof and exposed. The latter table factors in both direct heating and air heating from the hot roof.
But it would not hurt to use those same derating factors anyway as it would allow you to run the same wires and EMT exposed part of the way without the inspector freaking out.
 

north star

Senior Member
Location
inside Area 51
~ : ~

Article 310.15(B)(2)(c), in the `08 NEC, requires an
adjustment / derating, because the raceway(s) are
installed above the rooftop!.........Also, see Table
310.15(B)(2)(c).

~ : ~
 

sketchy

Senior Member
Location
MN
But the EMT will be shaded by the modules. So to me that means out of direct sunlight.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
But the EMT will be shaded by the modules. So to me that means out of direct sunlight.
But nevertheless, above the roof. Look at the exact wording of the rule: 310.15, 2011
...exposed to direct sunlight on or above rooftops
That seems to support you completely, but I would make sure that at no time during the day can sunlight get past the array to touch any part of the EMT run.
YMMV.
 
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Smart $

Esteemed Member
Location
Ohio
But nevertheless, above the roof. Look at the exact wording of the rule: 310.15
That seems to support you completely, but I would make sure that at no time during the day can sunlight get past the array to touch any part of the EMT run.
YMMV.
IMO, some direct rays of sunlight getting through the "cracks" of the array should not satisfy the condition... but ultimately determined by AHJ. However, 310.15(A)(2) Exception can be argued as negating the direct rays portion.
 
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suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
Does this array move? If not, the sun travels more than 180 degrees during the summer. It could get early morning or late evening sun from the NE and NW.
 
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