172 Modern Commercial Wiring Copyright Goodheart-Willcox Co., Inc. 180 volt-amperes per outlet. This receptacle load is in addition to the show-window lighting load. CODE ALERT Lights in Show Windows According to Section 410.14, chain-supported fi xtures used in a show window shall be permit- fi ted to be externally wired. No other externally wired fixtures shall be used. fi SAMPLE PROBLEM 12-3 Problem: le A department store has t tw o lighted show w windows, one 25′ long and t th e other 20′ lon ng . What are the branch-circuit i t requirements for fo the show-window load? Solution: Compute the load d based on linear feet of show window: Total length = 25′ + 20′ 2 0 = 45′ Show-window load ad = 45′ × 200 VA/ft = 9000 VA The lighting is a c co ntinuous load, so the show- window load is s multiplied by 1.25 to determine e the circuit load ad requirements: Circuit requirements e = 9000 VA × 1.25 = 11,250 VA The circuits c supplying power for the show-win- ho dow lighting li must have a minimum ca c ap acity of 11,25 2 50 volt-amperes. In n addition, receptacles are required ui for every 1 12 ′ of show window. A total of five fi receptacles fi fi (two for the 20′ window and t th ree for the 25′ window) are needed. The receptacle e load can then be computed: 5 × 180 VA = 900 VA Total load = 11,250 0 VA + 900 VA = 12,15 1 50 VA Track Lighting Track lighting is often used in commercial buildings for accent lighting. It is discussed in Part XV of Article 410 of the Code. The minimum load for track lighting is 150 volt-amperes for every 2′ of track. To compute the track lighting load requirements, simply determine the total length of track lighting, divide by two, and mul- tiply by 150 volt-amperes. Sign and Outline Lighting Article 600 of the Code discusses sign and out- line lighting. A structure must have at least one circuit exclusively used to supply sign or out- line lighting. The circuit must be designed for a minimum load of 1200 volt-amperes. SAMPLE PROBLEM 12-4 Problem: Determin ne the track lighting load fo f or a 22′ long section o of track. Solution: Every 2′ 2 requires 150 volt-ampe er es, so the length (in f fe et) is divided by 2′, and t th en ′ multiplied by 150 0 volt-amperes: Track lighting ng load = length__ __ 2′ × 150 VA A = 22′ __ 2′ × 150 VA = 1650 VA If this is a continuous c load, the circu ui t require- ments wou ul d also include a 1.25 facto t or . CODE ALERT Lighting Track According to Section 410.2, a lighting track is a manufactured assembly designed to support and energize luminaires (lighting fixtures) that fi are capable of being readily repositioned on the track. Its length can be altered by addition or subtraction of sections of track.