I am doing an arc flash calculations using SKM for a UV facility (2MW service) that has 480 volts UV reactors.

So when I talked to the electrician he asked me if I was going to do the calculations for the reactor panels and he told me that he needed to access those panels in order to calibrate the UV lamps. He said that the manufacturer install a second inside door where the UV reactors are behind these doors and the reactors are 2000 volts AC. When I saw the panel I realized that there is an electronic board and he needed to adjust some potentiometers using a small screw driver.

So, the service is 3 phase 480 volts, but once inside the cabinet there are 9 of these UV reactors that are 480/2000 volts single phase reactors with 50 Amps fuses on each reactor on the 480 volts side.

I do not have the UV reactor impedances. I will need to request it to the manufacturer, but the issue is that is single phase. So are the calculations accurate enough for this situation?

I found out that the reactor is a 480 volts AC input, 15 kV AC output, rated 20 kW, single phase. I do not have the impedance value.

There is no where in the drawing that says 15 kV DC and it is using a #14 wire for the 15 kV.