COMPUTER INTEGRATED OVERLOAD RELAY TESTING ANDDATA MANAGEMENT SYSTEM USING NI MY-DAQ INSTRUMENT

Thermal overload relays used for motor protection are most demanded in the commercial and domestic market. Batch line process is followed for overload relay assembly and testing. Testing Phase include test for several conditions like trip test, no trip test, mid trip test for suitable current ratings specified in the datasheet and continuity test. Existing test system carries out the testing procedure by human intervention to manually set up the test cases and test reports are generated. It's observed, the thermal overload relays passed in the test phase incurs high failure rate in the market scenario. The problem of thermal overload relay testing is addressed in this work, considering the combination of modern enabling technologies for data acquisitions and test measurement meters. An overload voltage protection PCB is developed to safety measure the data acquisition device. A computer integrated experimental test set-up is proposed to automate the overload relay testing process using NI myDAQ LabVIEW instrument. G-programming is used to implement the overload relay testing algorithm. Graphical user interface build in LabVIEW supports the testing operator to set the reference current ratings and reference trip time. Test reports data such as trip/non-trip/mid trip time current curves can be monitored and stored for various test cases are stored in the database through LabVIEW.