1. (Refer to Figure 4.) The following data concerning the installation of an electrical unit is known: current requirements for continuous operation â11 amperes; measured cable length â 45 feet; system voltage â 28 volts (do not exceed 1 volt drop); cable in conduit and bundles. What is the minimum size copper electrical cable that may be selected? A. No. 10. B. No. 12. C. No. 14.