Various organizations, including manufacturers, universities, and specifically tailored groups devoted to the application of direct current to devices in our daily lives, are deeply involved in the research, study, and application of DC circuits, DC devices, and DC microgrids.
Some actions can make the residential, commercial, and even larger PV systems more resilient and robust under the impending threat of more frequent severe weather.
As appliance and HVAC system efficiencies increase, load-side PV connections associated with smaller PV systems will be with us in great numbers.
Supply-side connected PV systems require renewed attention due to the more detailed requirements added to the 2020 NEC.
There have been substantial changes in various sections of the 2020 NEC, particularly in Article 706, which deals with energy storage systems (ESS). These changes suggest that we tread carefully when applying the various Code sections to a particular energy storage system.
This article will present an overview of some of the new PV systems that have evolving requirements in the NEC. They will include energy management systems (EMS), microgrid interface devices (MID), power control systems (PCS), DC microgrids (DCM), and energy storage systems (ESS).
PV disconnects provide a means to separate various portions of a circuit or equipment from other portions of the circuit or equipment in the same system.
Several different wiring methods may be used to route the power from the PV array to the utilization equipment.
Numerous Code requirements apply to the PV array and other equipment located in the vicinity of the array. These include conductors, DC combiners, arc-fault protection equipment, and rapid shut down equipment. This article addresses some of these requirements as they are found in the 2020 National Electrical Code (NEC).
A PV system is relatively simple in concept, but after the NEC requirements are added for safety, the execution of the system requires considerable attention to detail. There are also significant numbers of electrical inspectors that are new to the field of inspecting PV systems.