Which NEC article covers energy management and demand response devices?

• A. Article 300.
• B. Article 210.
• C. Article 220.
• D. Article 500.

Answer: (C)

The key idea is how to determine how much load the service and feeders must carry. Energy management and demand response devices influence the actual demand the electrical system must supply, so the rules for sizing come from the load calculation provisions. Article 220 covers branch-circuit, feeder, and service calculations and the use of demand factors to size equipment, which is exactly where controllable or demand‑responsive loads are accounted for when determining service and feeder sizes. The other articles deal with how wiring is installed or where certain locations apply, not with calculating load for sizing. So energy management and demand response devices are addressed through Article 220.