Voltage at the lamp holders. They and just a normal par38 light builb standard.First think I check was if they were MH with a regular buld dropped in.I found no balast just direct connection.The lights never worked since new. And there is no way to check how everything was wired. Main panel 208/120 lights are off of B phase. Hot 255V neutral vols.008 to .8. The same electrical contractor wired 21 175w MH around the shop. They installed the wire behind the bulb and I found 3 lights that burned and the rest have crispy cooked wire. The breakers never tripped pannel is FP stablock. There is also a ton more problems ill show pix latter on.