Abstract: A modular wiring system is disclosed for lighting and power distribution in office buildings, factories and the like. The modular wiring system utilizes a five-face connector assembly as its principal component for the distribution and control of power to lighting fixtures and power receptacles. The connector assemblies may be one of four types for providing different power configurations at the connector faces. The five-face connector assemblies all utilize the same housing and are economical to manufacture by using specially designed bus bars to obtain the desired power configurations and to provide the terminal connections. Other components of the wiring system mate with the five-face connector assembly to provide an efficient lighting or convenience power system which may be easily field modified.