Question 21

A grid-interactive PV system with battery backup is being installed with a ground-mounted PV array located
200 ft, from the inverter and batteries. The dc PV output circuit has overcuit has overcurrent protection rated from 30A. To reduce voltage drop between the array and batteries, the output circuit wire size was determined to be 6 AWG. The fused dc disconnect between the inverted and batteries is rated for 300A. What is the required size of the equipment grounding conductor between the metal battery case and the inverter?
  • Question 22

    The point-of-utility connection of a residential utility-interactive PV system is in the main distribution panel. If the busbars of the main distribution panel are rated at 200A, and if the distribution panel has a 200A main breaker, the rated output current of the inverter cannot exceed.
  • Question 23

    The AHJ for enforcement of the NEC has which responsibility?
  • Question 24

    A grid-connected PV system on a dwelling is producing 30% less power than expected. The conductors from threes strings of modules enter into a 3-pole fused dc disconnect, and each ungrounded conductor is connected to a separate pole. On the inverter side of the switch terminals, the three strings are combined. The dc disconnect switch is opened. The voltages on the array side of theswitchare 440 on string #1, 444V on string
    #2, and 0V on string #3. The dc disconnect is then closed and the inverter resumes operating, still producing about 30% less power than expected. A clamp-on ammeter is used to measure the dc current of each string of each string of modules where they enter the rooftop junction box. The operating currents of each string are
    3.9A for string #1, 3 85A for string #2, and 4.3 A for string #3. What is the MOST likely with the system?
  • Question 25

    An installer is using 1/2 in lag boits to secure roof-monitoring hardware to rafters through a roof deck. Which of the following should the installer predrill?