Each lug should read no more than +/– 0.3 to 0.9 volts of rated output. Both the LX-150 and LX-300 models have a 12V, 13V, and 14V lug inside the controller. The FX MultiTap Transformer allows you the opportunity to utilize the voltage tap that will provide each circuit with the proper voltage. For cable runs in the “distant zone” you would typically select the 13 or 14 volt tap. For cable runs in the “close zone,” you would typically install the cable run into the 12 volt tap depending upon the wattage load and size of cable.