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Change of Resistance Test Stand. Project Members: Colin Payne-Rogers Jacob Lennox. Project Guide/Mentor: Dr. Benjamin Varela. Primary Customer: Joe Manahan. Sponsor: Cooper Crouse-Hinds. Project Description.
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Change of Resistance Test Stand Project Members: Colin Payne-Rogers Jacob Lennox Project Guide/Mentor: Dr. Benjamin Varela Primary Customer: Joe Manahan Sponsor: Cooper Crouse-Hinds
Project Description Project Goal: To Design/Build a prototype test stand to measure the temperature of a maximum of 6 coils using a linear regression 4-wire resistance method. Project Overview: The test stand will include but is not limited to a cart/apparatus, laptop with LabView, data acquisition hardware, control circuitry and switching hardware, power dissipation circuitry and hardware. The apparatus is intended to use LabView to allow the user to run the test with minimal intervention. The prototype will be tested at RIT at 120VAC due to safety concerns.
Customer Specifications • Design and Build a Relay Circuit • Operation: 120-480VAC, 50-60Hz • Amphenol cable or similar connection • Controls electrical power for the operation • Select and Purchase a Digital Multimeter • Resolution: 0.01Ohms • Able to be calibrated • Select and Purchase a Data Acquisition System • Additional temperature measurement using thermocouple
Customer Specifications • Write a LabView program for the test stand • Communicate with and control measurement hardware • Measure the resistance of a maximum of 6 coils • 40 readings every 30 seconds (one reading at a time) • Operator flexibility on coil selection (for measurements) • Plot Resistance versus Time for each coil • Make a Linear Regression of the data to calculate the temperature of the data at the beginning of the test • Store the data in up to 9 different portable format files • Operator input: time, date, coil material • Selectable functions: pre-run test, run auto-test, view results, print results, terminate • All of the components must be contained in a rolling enclosure • Test Stand must comply with UL 844
Meeting Priorities • Agree on general circuitry concepts • The method to use for switching between each of the six coils • The method of power dissipation • Power dissipation circuit separate from control circuit • Digital Multimeter selection • Using the NI PXI system • Labview Licensing • Basic License • Data reduction in Excel
System Design LabView (Laptop) Printer Multi-Function DAQ Digital Multimeter 16/32 Channel Switch Power Circuit Relays Lamp/Ballast
System Decomposition • Design or purchase relay circuit • It appears as if we will be able to purchase a relay circuit to satisfy our needs • Need to design a method for switching between power and data collection circuits • Select and Purchase Multimeter • National Instruments PXI-4065 • Requires PXI Chassis • Select and Purchase Compatible Laptop • Create Labview interface
Relay Circuit • NI PXI-2566 • Allows switching between 16 relays • NI has modules with more relays • Fully software programmable with Labview • Can only withstand 125 VAC • How many channels will we need? • One for each coil or 4 for each coil
Power Circuit • Other Accessories • Multifunction Data Acquisition • Connector Block • Shielded Cable • Can control power switching and thermocouple • Hardware watchdog • Guards hardware in the event that there is a software failure
Switching From Power to Data Acquisition • Cannot be done with same relay circuit • PXI Switch cannot handle 480VAC • Need to add a separate relay that can withstand 480VAC • Electromechanical relay that can withstand 480VAC • Will be controlled directly through a digital output using the Labview interface • How is it being done now?
Risk Assessment • Safety of testing at 480VAC – technical risk • Only test at 120VAC at RIT, test at 480VAC at CHC • Hardware failure at 480VAC – technical risk • Hardware watchdog • “safety” relay circuit