The code uses the term "thread forming" instead.
Perhaps you have problem understanding what 'generally' means?
With all that you have said a handy box cover is to thin to tap threads into and be code compliant so thanks for the trip to nowhere.
Could these be used? I know they are a PITA, but they are a compliant means to attach a ground conductor without worrying about threads.
Cheers and Stay Safe,
Marky the Sparky
Nobody mentioned this, but it will draw 2.3 times the current. Is the branch sized generously enough that at 2.3 times, it stays under 80% rule?
I've never seen documented statement that 120-277v ballasts lock out, but that above would be a reason they might do so. Just depending on how loaded it was on 277v, running on 120v can leave the wiring at varying degree of overload.
Last edited by Electric-Light; 02-28-17 at 04:50 PM.