The lights were using some higher voltage. The Operations Manager mentioned it to me, while the work was being done. Apparently, it's standard. Something like 320 volts (don't remember the exact number). I had not heard of it, beforehand.
230V AC is the RMS (root mean square) voltage; if you rectify it to DC, it comes out to 325V. Put another way, the /highest/ absolute potential difference between line and neutral in a 230VAC system is 325V.
