As the comeback concert to mark the release of BTS's fifth studio album "Arirang (ARIRANG)" is set to take place on the 21st at Gwanghwamun Square in Seoul, work to supply outdoor power 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 power cables that will deliver electricity from the generators to the stage and the control tower that manages lighting, video, and sound.
An official from Wonkang Electric, who was working on cables at Gwanghwamun Square in Sajik-ro, Jongno-gu, Seoul, said on the 17th, "The amount of power we are installing is about 6,000 to 8,000 kilowatt-hours (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 concert industry, small concerts typically have one 100 kWh generator and one 200 kWh generator installed. A larger venue for TV CHOSUN's "Mr. Trot" uses one 300 kWh generator and two 200 kWh generators, for a total of 700 kWh.
Although "Mr. Trot" is an indoor show, 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 country's largest apartment complex, nicknamed "the largest since Dangun." Six thousand kWh is enough electricity for about 15,000 households for one hour.
◇ Generators installed near the Sejong Center for the Performing Arts, cable work to the stage
BTS's "BTS Comeback Live: Arirang" will run for one hour from 8 p.m. on the 21st. Because a pre-rehearsal and other preparations must be done, it is customary in the concert industry to complete stage installation at least a day in advance.
A Wonkang Electric official 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 show, the schedule is tight." Wonkang Electric has been working in two daily shifts since the 15th. During the day, eight employees and 20 part-time workers are on site; at night, seven employees and 10 part-time workers are working.
When a concert is held outdoors, generators are installed and electricity from the generators is supplied to the main stage and the control tower. Most of the generators have been placed inside a temporary partition next to the Korean Language Society's Monument to the Protection of Hangeul 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.
An official from Korea Airmen, one of the companies supplying generators for the concert, said, "We began installing generators on the 17th," adding, "About 30 to 40 units ranging from 500 kWh to 400 kWh, 300 kWh, 200 kWh, and 100 kWh will be installed according to capacity, and on the 17th alone we installed 15 large-capacity units."
For cables, four power lines for lighting, video, and sound and one grounding line make up a single set. Of the four power lines, three supply the electricity generated by the generators, and the remaining line returns unused power from the stage or control tower to the generators.
The grounding line diverts electricity outward if voltage problems cause a sudden surge to leak out, preventing current from flowing into the stage or to people.
An official in the cable industry said, "The required power for lighting, video, and sound will differ, so the work likely involved laying one set of cables tailored to each," adding, "Industrial cables are used at venues and can typically carry currents under 1,000 volts (V)."