National Electrical Code Articles and Information

1.      [220.1]. It provides the requirements for calculating branch-circuit, feeder, and service loads. This makes it one of the most important Articles to study and understand.

2.      [220.3]. More than 10. Table 220.3 shows over two dozen entries, some of which are repeated.

3.      [220.3]. No. This is a common source of misunderstanding and misapplication. These other Articles use Article 220 as the starting point. In fact, the first four Chapters apply generally to all installations [Figure 90.3]. Chapters 5 through 7 supplement or modify Chapters 1 through 4 [Figure 90.3].

4.      [220.5(A)]. No.

5.      [220.5(A)]. You must use nominal system voltages of 120V (not 115V), 120/240V (not 110/220), 240V, 347V, 480Y277V, 600Y347V, and 600V.

6.      [220.5(B)]. No. In such a case, the NEC permits you to drop that fraction of an ampere. Note that this is for the results of a calculation.

7.      [220.12]. Use Table 220.12 to determine general lighting loads by occupancy.

8.      [220.14(D)]. Calculate these based on the maximum volt-ampere rating of the equipment and lamps for which the luminaire is rated.

9.      [220.14(E)]. 600 VA.

10.  [220.14(I)]. Except as covered by 220.14(J) and 220.14(E)—dwelling occupancies and banks/office buildings, respectively—the minimum is 180VA for each single or multiple receptacle in one yoke. But if a single piece of equipment consists of a multiple receptacle comprised of four (or more) receptacles (four example, a four-gang receptacle box or strip), then the minimum is 90VA per receptacle. This means, for example, you would allow 180VA for a duplex receptacle unit but 360VA for a four-gang receptacle unit.