What is the required height for the label indicating the presence of rapid shutdown in PV systems?

The requirement for the label indicating the presence of rapid shutdown in photovoltaic (PV) systems is specified in the National Electrical Code (NEC) under Article 690. According to these regulations, the height of the letters on the label must be a minimum of 3/8 inches. This standard is set to ensure that the label is legible and can be easily read by emergency responders and anyone interacting with the system.

Using a height of 3/8 inches helps ensure visibility while not being excessively large, which could lead to clutter on the label. It's essential in safety-related applications to have clear and concise labeling that communicates critical information effectively without overwhelming other necessary data. Therefore, the correct answer highlights the appropriate requirement for clear communication regarding the safety features of PV systems.