[RE-wrenches] Ground Mount Screening

[Drake]

Bill,

Thanks for the good idea.  Using a nonconductive material for the 
screening makes sense.  Lattice should be sufficient to keep hands, 
especially "little hands," away from the wiring.  My understanding of 
the rule is that protection is required to prevent easy access to the 
always energized DC wiring, not the 240 VAC which will de-energize 
when the wiring is disconnected.  Lattice should be adequate, if it 
makes the AHJ happy.

Drake


At 05:57 PM 10/21/2010, you wrote:
>Drake,
>
>I recommend using 4'x8' panels of lattice work that is either wood or PVC so
>that you don't have worry about grounding the material. It is reasonably
>attractive and can hide some of the ugly parts of the array. The panels can
>be held on with battens that screw into the structural member and allow for
>panels to be removed in case the array wiring needs to be maintained.
>
>Bill.
>
>
>-----Original Message-----
>From: re-wrenches-bounces at lists.re-wrenches.org
>[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Drake
>Sent: Thursday, October 21, 2010 9:35 AM
>To: RE-wrenches
>Subject: [RE-wrenches] Ground Mount Screening
>
>Hello Wrenches,
>
>We are installing a ground mount system with Enphase
>inverters.  690.31 requires readily accessible source and output
>conductors OPERATING at over 30 volts to be installed in a
>raceway.  The Vmp of the REC230PE modules is 29.4 volts.  Of course
>it would go higher in cold weather.  Do I have any argument that
>would allow us to not install the DC conductors in a raceway?
>
>The NEC Handbook comments "Most PV modules do not have provisions for
>attaching raceways. These circuits may have to be made "not readily
>accessible" by use of physical barriers such as wire screening".
>
>I have heard of a green screening material that has been used on the
>E, W and N sides of ground mounts to render the area not readily
>accessible.  Does anyone know what this is?  What else would work
>that would be more cost effective than running a chain link fence
>around the array?
>
>Thanks,
>
>Drake
>
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