As BTS holds a comeback concert on the 21st at Gwanghwamun Square in Seoul to mark the release of its fifth full-length album, "Arirang," work to set up outdoor power supplies to run lighting, video, and sound is also picking up speed.
As of the 18th, generators are being installed near the main stage on the north side of Gwanghwamun Square, and work is steadily underway to lay cables that will send electricity from the generators to the stage and to the control tower that manages lighting, video, and sound.
A representative from Wonkang Electric, who was working on cable installation at Gwanghwamun Square in Sejong-ro, Jongno-gu, Seoul, said on the 17th, "The installed power capacity is about 10,000 to 12,000 kilowatts (kWh)," adding, "The distance from the generators to the stage is about 350 meters (m), and we have to lay cables along this section."
According to the performance industry, small concerts typically have one 100 kWh generator and one 200 kWh generator installed. At the larger TV CHOSUN "Mr. Trot" venue, one 300 kWh generator and two 200 kWh generators are used, for a total capacity of 700 kWh.
Although "Mr. Trot" is an indoor performance, the generator capacity for the BTS concert is more than eight times that. It also exceeds the amount of electricity used in one hour by "Olympic Park Foreon (12,032 households)," the largest apartment complex in Korea, nicknamed "the largest since Dangun." Ten thousand kWh is enough electricity for about 25,000 households for one hour.
◇ Generators set up near the Sejong Center for the Performing Arts, cable runs to the stage
BTS's "BTS Comeback Live: Arirang" performance will run for one hour from 8 p.m. on the 21st. Because advance rehearsals and other preparations must be conducted, industry practice is to finish stage installation at least a day earlier.
A Wonkang Electric representative said, "We have to power up the main stage today (the 17th)," adding, "We started work at 3 p.m. on the 15th, and considering the scale of the performance, the schedule is tight." Wonkang Electric has been working in two daily shifts since the 15th. During the day, eight Wonkang Electric employees and 20 temporary workers are on site, and at night, seven employees and 10 temporary workers are working.
When a performance is held outdoors, generators are installed and electricity produced by the generators is supplied to the main stage and the control tower. Most of the generators have been installed inside a temporary partition set up next to the Korean Language Society's Korean Script Protection Monument near the Sejong Center for the Performing Arts, not far from the main stage on the north side of Gwanghwamun Square. Some generators are installed about 20 meters from the main stage.
A representative from Korea Airman, one of the companies supplying generators for this performance, said, "We began installing generators on the 17th," adding, "About 30 to 40 units ranging from 500 kWh, 400 kWh, 300 kWh, 200 kWh, to 100 kWh will be installed according to capacity, and we installed 15 large-capacity units on the 17th alone."
For cables, four power cables and one grounding wire form a single set for each of lighting, video, and sound. Of the four cables, three carry the electricity generated by the generators, and the remaining one returns unused electricity from the stage or control tower back to the generators.
The grounding wire prevents electricity from flowing to the stage or to people by diverting it outward if an instantaneous surge causes a voltage problem that pushes electricity outside the system.
A representative from the cable industry said, "The power needs likely differ for lighting, video, and sound, and they would have laid a set of cables accordingly," adding, "Venues use industrial cables, which typically can carry currents of up to 1,000 volts (V)."