What is the maximum allowable voltage outside the array boundary during rapid shutdown initiation within 30 seconds?

The maximum allowable voltage outside the array boundary during rapid shutdown initiation within 30 seconds is 30 volts. This requirement is established to ensure safety during maintenance or emergency situations when rapid shutdown systems are engaged. The voltage level is set at 30 volts to minimize the risk of electrical shock to first responders and personnel who may be working around the photovoltaic (PV) array after it has been shut down.

Understanding the context behind rapid shutdown is crucial; this system is designed to quickly reduce the hazardous output of a solar array to a safer level. During this process, preventing high voltages from persisting outside the array boundary is vital, which is why the NEC has specified this limit. The 30-volt threshold offers a balance between ensuring that the system can operate effectively while also prioritizing safety for anyone in proximity to the PV installation.

Other options present higher voltage levels which do not align with the safety measures put forth by the NEC concerning rapid shutdown systems. Hence, the choice of 30 volts as the maximum allowable voltage is in direct correlation with safety guidelines established in the NEC, ensuring a safer environment for everyone involved.