NABCEP Grid Interconnection 3

Question 1

During the utility interconnection application process, what typically triggers a 'Supplemental Review' (or detailed study)?

Accepted Answer

The system fails initial fast-track screening due to potential adverse grid impacts

Answer

Use of string inverters instead of microinverters

Answer

All commercial systems regardless of grid impact

Answer

Use of battery storage in addition to solar panels

Question 2

What is the purpose of a 'Permission to Operate' (PTO) letter issued by the utility?

Accepted Answer

Official utility authorization confirming the system has passed all inspections and may begin exporting power to the grid

Answer

Building department authorization to begin solar installation work

Answer

Permission to install a revenue-grade bidirectional meter

Answer

Authorization from the AHJ to energize the AC disconnect switch

Question 3

Which NEC article primarily governs the installation requirements for solar photovoltaic systems in the United States?

Accepted Answer

Article 690 (Solar Photovoltaic Systems)

Answer

Article 480 (Storage Batteries)

Answer

Article 705 (Interconnected Electric Power Production Sources)

Answer

Article 230 (Services)

Question 4

NEC Article 705 is relevant to grid-tied solar installations because it covers:

Accepted Answer

Interconnected electric power production sources and their connection to premises wiring

Answer

Battery energy storage system requirements

Answer

Solar panel module construction and ratings

Answer

Grounding and bonding methods for PV arrays

Question 5

What power factor range must grid-tied PV inverters typically maintain at the point of interconnection under IEEE 1547?

Accepted Answer

Between 0.85 lagging and 0.85 leading

Answer

Unity power factor (1.0) at all times

Answer

Greater than 0.85 lagging only

Answer

Greater than 0.95 lagging at all load levels

Question 6

What does the 'interconnection queue' refer to in the utility approval process for solar PV projects?

Accepted Answer

The ordered list of distributed generation projects awaiting utility grid impact studies and interconnection approval

Answer

The ranked waiting list of solar installers seeking utility certification

Answer

The sequence of electrical connections made during PV system installation

Answer

The priority hierarchy of overcurrent protection devices in the system

Question 7

A utility may require 'transfer trip' protection on a larger commercial or utility-scale solar installation in order to:

Accepted Answer

Remotely and rapidly disconnect the solar generation system from the grid during utility emergencies or maintenance

Answer

Transfer the facility's load to battery backup power during a grid outage

Answer

Transfer excess solar power to neighboring customer accounts

Answer

Upgrade the inverter's power output capability during periods of peak grid demand