November 4, 1940
NEW VARMETER - Gadgets
General Electric Co. Schenectady, N. Y.
2/4/2008 Courtesy < http://www.wbdg.org/ccb/NAVFAC/OPER/mo201.pdf >
A varmeter measures reactive power. VARIABLE SPEED ELECTRIC DRIVE SYSTEMS
A varmeter operates as a wattmeter with the current coils connected in series with the circuit and the voltage phase shifted 90 electrical degrees from the voltage across the circuit. Varmeters usually have the zero point at the center of the scale, since reactive power may be leading or lagging. The varmeter has an advantage over a power factor meter in that the scale is linear, and small variations in reactive power can be read. A power factor meter may be difficult to read near unity power factor.