The arithmetic system is good for only the balanced system, but does not work for
unbalanced or distorted systems. The 2D VA measurement system is suitable for balanced as well as unbalanced systems, but does not measure the distortion.
Conzerv meters come two options: arithmetic VA for balanced systems, and 3D VA which works for all balanced, unbalanced, and distorted systems. This results in accurate KVAh measurements and hence correct energy usage billings.