This paper presents a study of transformer monitoring and load tap-changer control. Earlier control schemes were the “paralleling balancer”, the “master/follower” and the “circulating current” schemes. These schemes had their drawbacks. The scheme as presented in this paper is implemented using programmable logic, math functions and IEC 61850 communications over fiber-optic Ethernet. The presented scheme achieves ease and speed of installation, a more integrated system with less field using, minimal control cable runs and terminations and minimal overall installation time. With SCADA control accomplished over a DNP3 loop, need for electromechanical switches is eliminated. The LTC control was field tested on three parallel 230/115KV autotransformers on the Santee Cooper system.