Quick Answer
Rapid Shutdown Devices are required on all solar roof types that have a DC power output of 80 volts DC or more, and are installed on buildings with roofs that are less than 20 feet off the ground.
When Do Rapid Shutdown Devices Apply?
Rapid Shutdown Devices (RSDs) are required by the 2014 NEC (National Electric Code) to ensure safe and compliant operation of solar electric systems. They are typically required on systems that have a DC power output of 80 volts DC or more. This threshold can vary depending on the specific NEC edition, location, and local regulations.
Installation Requirements for RSDs
RSDs must be installed according to the manufacturer’s specifications and the NEC requirements. Typically, RSDs are installed at the inverter or module level, where they can quickly disconnect the DC power when the system is not in use. For roof-mounted systems, the RSD is usually installed near the inverter or at the DC disconnect. In some cases, RSDs may be required at the module level for certain types of solar roof installations.
Types of Solar Roof Installations Requiring RSDs
RSDs are required on all solar roof installations that meet the 80-volt DC threshold, regardless of the type of solar panel or roof system. This includes:
- Solar roof shingles with DC power output above 80 volts DC
- Solar roof tiles or panels with DC power output above 80 volts DC
- Building-integrated photovoltaic (BIPV) systems with DC power output above 80 volts DC
- All solar roof installations on buildings with roofs less than 20 feet off the ground, regardless of the DC power output.
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