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Below are citations from the National Electric Code (NEC) that dictate that wire guarding must be installed under ground-mount arrays in which the voltage exceeds 30 volts.
Unfortunately there are installations allowed in the county in which I reside, San Luis Obispo County, that do not comply with the code. See this link for a web-page showing photographs of such an installation. These non code-compliant installations are being allowed by the San Luis Obispo building Department. I contacted the county building department but they refuse to enforce the building code. Here is a link to a web page showing the communications with the San Luis Obispo County building department. It is my opinion that the San Luis Obispo Building department is acting negligently and putting the residents of the county, especially the children, at risk.
See this link for work we have done at Miller Solar to develop safe wire guarding techniques.
The National electric Code governs electrical wiring practices in the United States. Much time and effort has been put into developing the code over the years in an effort to prevent injury, death and property damage. There are many stipulations on the code about wiring practices for Photovoltaic (PV) systems. One section, cited below, refers to the protection of high voltage PV wiring from accidental contact by people.
The relevant code sections are below:
From 2017 NEC section 690.31(A): Where PV source and output circuits operating at maximum system voltages greater than 30 volts are installed in readily accessible locations, circuit conductors shall be guarded or installed in Type MC Cable or in a raceway.
From 2017 NEC, definition of readily accessible: Accessible, Readily (Readily Accessible). Capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to take actions such as to use tools (other than keys), to climb over or under, to remove obstacles, or to resort to portable ladders, and so forth.
From 2017 NEC, definition of guarded: Guarded. Covered, shielded, fenced, enclosed, or otherwise protected by means of suitable covers, casings, barriers, rails, screens, mats, or platforms to remove the likelihood of approach or contact by persons or objects to a point of danger.
From 2017 NEC, definition of Enclosed: Enclosed. Surrounded by a case, housing, fence, or wall(s) that prevents persons from ccidentally contacting energized parts.
From book Design Guide to the 1997 Uniform Building Code (Hardcover) by Richard T. Conrad: The enforcement official who chooses to ignore the code...places both the jurisdiction and the official in serious jeopardy. Cases have ruled that both the individual and the jurisdiction can sustain liability if the action by the official was knowingly wrong. (page 415)
From Mike Holt of (Mike's response in italics):
  1. Q: Does the 2014 NEC require, for all installations where PV wire is readily accessible, guarding of the PV conductors such that they cannot be touched? A: Yep…
  2. Q: Looking a little deeper into the issue, are ground mount solar arrays typically considered readily accessible? A: Yep…

Hope this is clear – you are 100% correct.