How many 20A branch circuits are required for 80 linear feet of show window lighting space?

To determine the number of 20A branch circuits required for 80 linear feet of show window lighting space, one must consider the allowed load per circuit and how much lighting will be used in that specific setting.

Typically, a 20A circuit is capable of supporting a certain amount of wattage. For lighting, the National Electrical Code (NEC) usually recommends calculating the load based on a specific wattage per foot of lighting, which can vary depending on the type of fixture being used. However, common practice is to use 2 watts per linear foot for general lighting calculations.

For 80 linear feet, the total wattage would be:

80 feet x 2 watts/foot = 160 watts.

Next, calculate how many 20A circuits are needed. The formula to find the total amperage per circuit is:

Total watts / Voltage = Amperage.

In most cases, for branch circuits in the U.S., the standard voltage is 120 volts. Therefore:

160 watts / 120 volts = approximately 1.33 amps.

Since this is well below the 20 amps that a single circuit can handle, you may think initially that only one circuit is needed. However, commonly specified guidelines suggest providing a minimum number