The ornamental design for an electric powermeter, as shown and described.
FIG. 1 is a top, front and left side perspective view of an electric power meter;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is a top, front and left side perspective view thereof in an opened position; and,
FIG. 9 is a top, front and right side perspective view thereof in the opened position.
The dashed broken lines in the figures show portions of the electric power meter that form no part of the claimed design. The dot-dash broken lines in the figures show boundaries of the claimed design.