it was a direct replacement for incadescent lamps in series circuits but it use the transfromer
and high voltage regulated at predefined current. now power companys are ripping up series streetlights because it hard to maintain esspecialy when you have a break in the circuit.
let say you have 100 250 watts series
those ballast runs at 37.8 volts each
runing 6.6 amp. that why it take such high voltage. that what make me want one becase can
invert a low voltage mercury ballast in solar application. double tranforming them at
120 volts then you got the CWA ballast there for; it would make the worse effeincy possble
in this application.