In recent years, research into energy saving has been increasing in view of dealing with environmental problems and effectively using energy resources. In a plant, power consumption monitoring of individual inductive devices like motors would have significant impact on energy savings in the long run. However, the current practice of measurement of power consumption of the whole plant rather than individual devices results in penalties for energy losses due to variation of demand charges in a plant. Therefore, electrical power consumption monitoring on a real-time basis is essential to keep it from exceeding the critical demand level. Power meters are practical energy saving devices that can help monitor electricity consumption in a plant. This paper discusses the development and implementation of a micro-controller based portable digital power meter that has the capability to measure three phase power supply for a single device in order to optimize power usage in a plant. It could also be used as an educational tool for undergraduate studies. © 2012 IEEE.