lapelectric
New member
I recently saw a 3 lamp programable ballast which appeared to be wired wrong but was still working. The blue/white Wires that I will refer to as common because it connects to two tombstones. I see the wires both connecting to one tombstone then jumping to the other. On this installation the electrician connected one blue/white to one tombstone. The other to the second tombstone then installed a jumper between both ? Is this acceptable and if not why did the lamps lite and does this damage ballast