Channels, Fall 2016

Page 102 Newman, Tomlinson, Dearing, Harmon • AC Power Monitoring System Project Specifications After meeting with our advisor and our customer, we established a set of specifications for our project to create feasible outcomes as well as develop a manageable scope for the project. After deliberation and multiple modifications, the following specifications were developed:  System o The system must be safe to install and operate. o Thirty individual circuits must be monitored for their energy consumption. o Energy consumption data must be displayed to the user in an organized and understandable manner. o The system will be installed on a circuit breaker box in Cedarville University’s Chemistry Lab Building. o Any user should be able to install the system with simple instructions. o The system should be easily mounted on the wall next to circuit breaker box.  Safety o Direct connections to any active part of the breaker panel must be fully enclosed and electrically isolated from the rest of the system. o The voltage signal coming from the breaker box must be stepped- down to the monitor. o Current transformers should be non-invasive to avoid disconnecting wires within the breaker panel. o Current transformers must have voltage protection built in to avoid high-voltage open circuits on their output.  Power o All power must come either from the two 120-V 60-Hz outlets that are inside the circuit breaker box, or through a direct connection to the bus bar.  The Raspberry Pi should be powered by its supplied AC-DC converter, so it takes one outlet.  The other outlet must supply power for the rest of the system, as well as be the monitored voltage signal. o Positive and negative supply voltages must come from the same source.  PIC supply voltage: +5  Operational Amplifier positive supply voltage: +3.5 < V cc < +18  Operational Amplifier negative supply voltage: -3.5 > V cc > -18  Calculations o Our system must be able to calculate the following information about each circuit:  Instantaneous Current  Instantaneous Voltage  Instantaneous Power