CanadianSparky;
probably the most prevalant 3 ph is 208/120Y folowed by 480/277Y .
Virgil;
i worked for a lot of different contractors here that knew nothing of safety practices or PPE, they would simply joke that i was not to get paid for 'welding'. Some would even make up service drops bare handed. It took me quite a while to realize my upbringing in this trade was outragoeusly flawed, so don't be impressed with my ignorance. [Linked Image]
Today if i visit similar situations i will ask the customer if he/she would like me to trace out the circuit or shut the main off, and i'll usually leave one of my computer generated panel scheduled for them.
There are, however, situations that require that i do live work. A common case in point is making on an overhead service drop, i would be interested in how others go about this. [Linked Image]