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IAEI Magazine | Author: James Rogers
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James Rogers



Electric Vehicles

There is no better time than the present to discuss the merits of alternative fuel sources. As the price of gasoline exceeds $2.00 per gallon in many parts of the country the thought of electric vehicles is much more enticing. Add to this the effort that many major automobile manufacturers have put into developing practical electric vehicles and the concept appears to be one whose time has come.

Focus on the Code

Are there any provisions in the NEC that address the de-energizing of rooftop photovoltaic (PV) wiring in an emergency situation for first responder emergency personnel?

Let’s begin with de-energizing. It is well understood that when electrical circuits and equipment are de-energized, they are disconnected from a source of power utilizing a disconnecting means. Using this analogy, your question could be rephrased to inquire if there is a requirement for a disconnecting means for PV circuits; that direct answer is yes.

Question: Both dc and ac photovoltaic systems in a common enclosure?

Section 690.4 is the first section of the 2011 NEC that covers the installation raised in the first portion of your question. There seems to be one summation that is being made for clarity, the question inquires about "both dc and ac photovoltaic systems.” The summation being made deals with a common junction box where the PV output circuit conductors and the inverter output circuits are both present on an interactive system.