TEST METHOD FOR CHECKING TRUNK LINE WORK VOLTAGE AND PHASE AND POWER SUPPLY DEVICE USED THEREFOR

PROBLEM TO BE SOLVED: To provide a test method capable of significantly facilitating checks of a voltage and a phase on a branch circuit before and after built-up and switching work of trunks for a substation or the like.SOLUTION: After a trunk line 11 for newly installed power and a trunk line 12 for newly installed electric lamps are connected with an existing trunk line 1 for power and an existing trunk line 3 for electric lamps, respectively, a low voltage is applied to each of the connected trunk lines 11 and 12 from a newly installed substation B side, one position of a power board 6 and a distribution panel 9 which can facilitate checking work is selected in each branch circuit 5 or 8, and voltage and phase checks are performed at positions of the power board 6 and the distribution panel 9 located at the position.