Using NEC Table 220.42(A), what is the min general lighting load required by the NEC for an office building?

Using NEC Table 220.42(A), what is the min general lighting load required by the NEC for an office building?

• A. 1.3 VA per sqft
• B. 1.0 VA per sqft
• C. 2.0 VA per sqft
• D. 0.5 VA per sqft

Answer: (A)

The main idea here is that the NEC uses a fixed, per-square-foot lighting load to size feeders and services. Table 220.42(A) assigns a minimum general lighting load by occupancy, so designers don’t rely only on the exact wattage of installed fixtures. For an office building, the table specifies 1.3 VA per square foot. So, to apply it, multiply the office area by 1.3 VA/ft² to get the minimum lightingVA, then divide by the system voltage to estimate the required amperes for sizing. This value reflects typical lighting density and system losses as a baseline, ensuring code compliance even if actual fixtures differ. The other numbers correspond to different occupancies or interpretations from the table, not the office category, so they don’t fit this particular scenario.

The main idea here is that the NEC uses a fixed, per-square-foot lighting load to size feeders and services. Table 220.42(A) assigns a minimum general lighting load by occupancy, so designers don’t rely only on the exact wattage of installed fixtures. For an office building, the table specifies 1.3 VA per square foot.

So, to apply it, multiply the office area by 1.3 VA/ft² to get the minimum lightingVA, then divide by the system voltage to estimate the required amperes for sizing. This value reflects typical lighting density and system losses as a baseline, ensuring code compliance even if actual fixtures differ.

The other numbers correspond to different occupancies or interpretations from the table, not the office category, so they don’t fit this particular scenario.