The new AC powerless panel meter, Model TAC,
monitors 1 or 3 phase, “delta” or “Y” AC power lines.
The unit features multicolor 0.8-in., 3-?-digit LED
displays. It is powered by the signals that it measures
for AC volts, amps, watts and hertz. The burden on
the AC volts is only a few milliamps directly from
the mains or from a P.T. The amps use the customer’s
existing C.T. to derive the signal and power.