Sub-Metering System


GridNavigator’s electricity metering solution is a multi phase sub-metering system that accurately reports the energy consumption of a three-phase, or single phase load. The configuration challenges that every installer faces have been eliminated using the GridNavigator EMS smartphone app’s real-time views of the RMS voltage & current, Apparent Power and Power Factor of each phase. A feature-rich app (available on both iOS and Android) shortens the installation time and lowers the cost. GridNavigator’s electricity metering solution also includes a demand forecasting service. "Traditional" demand management is usually done by observing quasi-real-time values (either campus/building demand, or utility demand) and then doing demand management at that time. The demand LIMIT is usually set lower than the true target, so that the controls have time to operate and shed loads or limit power usage.

The BMS is always "working behind" -- it is never in front of energy usage; it is always reactive, with gross controls. Demand forecasting provides greater insight: not only it forecast peak power consumption, but it also predicts when this peak will occur, and the rate-of-change of both usage and demand. This allows the Building Automation System to apply more intelligent controls: widen setpoints, but only for as long as necessary to get through a demand peak; intelligently shed loads or reset CHW or HW supplies; limit flows, clamp air exchanges and limit maximum flows. With predictive control, the operations do not have to be as "bang-bang" and control as gross as with the traditional demand management approach that only relies on latent values. Much greater occupant comfort is possible, and finer control can be achieved. Some critical peak situations, where the peaks are predicted to be short, would have little effect on occupant comfort, whereas traditional demand management would have initiated more draconian equipment shutdowns, and the concomitant discomfort for humans. GridNavigator electric metering is also linked to Energy Star rating system. Each month the automated link sends the collected data usage to EPA and obtains the new Energy Star rating for the facility. This industry standard rating helps facility manager and owners with the critical information necessary to provide occupants’ comfort, to accurately program energy usage, and to ensure maximum energy savings.