Installing Solar Electric Since 1983

 

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Site Inspections

Below are links to a checklist, code citations, photographs and diagrams to assist the building inspector in performing thorough and efficient inspections of solar electric installations.
We suggest inspections start at the PV modules and work downwards.
Check list: Linked is a written checklist that can be taken on site inspections. Feel free to modify this to suit your department. Below are photo links to illustrate code citations and concepts.

Below are details on some of the issues covered in the checklist.

Modules over the ridge:

We have found that the wind forces on a row of modules extending over a ridge far exceed those exerted on modules below the ridge and flat against the roof. This case study shows an example of this. Here are more photos of this phenomena. We recommend that installations such as this require a structural analysis.

PV wiring protected from damage:

Section 300.4 indicates:

300.4 Protection Against Physical Damage. Where subject to physical damage, conductors shall be adequately protected.

This link shows some installations that exhibit potential for damage to occur to PV wiring. We submit that the abrasive nature of roofing guarantees that loose wiring will eventual exhibit exposed conductors. We remind building officials that these days, voltages in PV wiring systems often approaches 600 VDC and is FATAL. The link also shows some ideas for how to minimize the potential for the wire to become damaged.

Many manufacturers prohibit use of unprotected wire where children or small animals can access these wire. Here is a link to the SolarWorld installation instructions. (See highlighted note on page 2.)

This link illustrates some actual cases of electrocution deaths in related accidents.

Also, section 110.12 indicates that all work be done in a workmanlike manner. Photos in the above links illustrate some problems some installers have with this concept.

PV ground wire either protected in conduit or #6AWG or larger:

Applicable code sections:

690.43 Equipment Grounding. Exposed non–current-carrying metal parts of module frames, equipment, and conductor enclosures shall be grounded in accordance with 250.134 or 250.136(A) regardless of voltage.

250.120(C): Equipment Grounding Conductors Smaller Than 6 AWG. Equipment grounding conductors smaller than 6 AWG shall be protected from physical damage by a raceway or cable armor except where run in hollow spaces of walls or partitions, where not subject to physical damage, or where protected from physical damage.

At issue is this point: Are grounding conductors protected at the back of a roof mount rack? We submit not in that balls and frisbees tend to become stuck under roof mount racks and children will probe for them with whatever object is handy. Also, we have heard often about squirrels chewing insulated wires. We are very clear that any wiring at the back of a ground mounted rack is not protected by the rack and needs protection by conduit, wire shield or fencing.

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