Quote Originally Posted by dhouston View Post
. . . Most residential meters measure watts but most commercial and industrial sites have demand meters which measure peak current. . . .
And as I understand it, the leg of the circuit which is consuming the greatest power is the one which you pay for, which is to say if you have 3 phase comming into the building and you are using 120 1 phase @ 2000 watts and 3 phase @ 2000 watts you will be billed @ 4000 watts.