AE 868
Commercial Solar Electric Systems



Lesson 8 Scenario

Assuming the client, for whom you designed the interactive PV system in Lesson 6, closed the deal with the solar firm you work for. The next day, the design manager asks for the actual PV system design and documentation to be prepared. You happen to be a new employee with a good electrical engineering design background. However, your background is not directly related to PV systems. As you are familiarizing yourself with the PV electrical design process, you receive a call from the manager saying you are assigned a new project that requires electrical design to comply with the local codes. Fortunately, the NEC is adopted by the AHJ at the place where the system will be installed.

You previously learned that International Solar Energy Provisions adopted the NEC articles that relate to PV systems. So your first task is to understand and interpret the PV terminologies on the NEC and then interpret the articles that specify PV design requirements.

You noticed that NEC articles require an understanding of maximum voltage design, conductor ampacity and correction factors, voltage drop calculations, grounding and lightning, and the protection requirements.

In this lesson, we will train our PV designers to perfectly interpret the NEC articles that pertain to PV systems, and we will walk them through sizing and calculation processes to address the design issues mentioned earlier. Learning about NEC articles allows better understanding of the PV system as it integrates with other electrical systems. The knowledge available in this lesson is of interest to a wide range of audiences including designers, business owners, installers, or inspectors.

Learning Outcomes

At the successful completion of this lesson, students should be able to:

  • Identify applicable fire and safety regulations affecting PV design and installation.
  • Compare theories and practices for overcurrent protection and arc-fault protection.
  • Calculate the voltage and current limits for various circuits of PV systems.
  • Determine appropriate conductor ampacities and overcurrent protection ratings and types of conductors used for PV applications.
  • Identify grounding requirements and electrical grounding methods.

What is due for Lesson 8?

Lesson 8 will take us one week to complete. Please refer to the Calendar in Canvas for specific time frames and due dates. Specific directions for the assignments below can be found within this lesson and/or in Canvas.

Complete the following Lesson Assignments:

*Students who register for this Penn State course gain access to assignments, all readings, and instructor feedback, and earn academic credit. Information about registering for this Penn State course is available through the Renewable Energy and Sustainability Systems Online Masters and Graduate Certificate Programs Office (link is external).


If you have lesson specific questions, please feel free to post to the Lesson 8 Questions discussion forum in Canvas. While you are there, feel free to post your own responses if you, too, are able to help a classmate with a question. If you have questions about the overall course or wish to share and discuss any "extra" course related commentary (interesting articles, etc.), please feel free to post to the General Questions and Discussion forum.