merajdab Posted September 6, 2003 Report Share Posted September 6, 2003 Hi friends I have to test MOPN 01 motor protection relay from ALSTOM.It monitors current in two phases only and the earth fault current is obtained from a corebalance ct or residually connected cts. Here I have detailed my problems and the text is slightly long , but I would appreciate if u could pls take some time and read it to help me out. I thank all of those who chose to open it and read it. Thank u in advance. My problem is that I do not have a current injection set that could give me two currents at a phase angle of 120 deg or a phase shifter that I could use for the purpose.I have only one single phase current injection set. Hence I am confused about simulating the conditions for test with a single phase unit. Moreover I have never tested this relay before , so I request someone with deeper knowledge to please look at it and give comments. CONSIDER THE FOLLOWING DATA I thermal .88 In Te1 9 minutes Te2 Te2=Te1Tr(cooling time constant) 45 minutesE1(start inhibit threshold- % of thermal capacity) 40% -motor once stopped will not restart until the thermal capacity is above this valueE1(start inhibit threshold-% of thermal capacity) 90% - relay will give alarm when this amount of thermal capacity is spentPh Isc- Ph short circuit protection ( provided for protection against shortcircuit at the motor terminals) 1.2 starting currentIo ( earth fault setting ) .4 InI2 (Negative sequence setting ) .2 InIs ( starting current threshold) 3*I thermal Tb (Starting time) 6.0 secondsTb1(Time to trip on stall ) 1.6 seconds I have decided to test the relay in the following manner and I request you to kindly check if there is a problem 1. To check the earth fault unitInject a single phase current equal to earth fault setting in the designated terminals and verify that the trip occurs after the set time delay2. To check the short circuit current threshold IscInject a current equal to 1.2 times starting current in any one of the phase monitoring units of the relay and verify that the relay picks up after 100ms(given fixed value by the manufacturer) OrInject 1.2*starting current into both of the phase monitoring units connected in series and verify the trip as said above3. To check the negative sequence unitInject 0.2In into any one phase monitoring unit and the relay should pick up after a fixed time delay (if any).4. To check the cold thermal curveSelect a value of the current from the cold curve and inject a single phase current in both the phase monitoring units connected in series and verify the time from the curve.- to be done for at least three values.5. To check the thermal threshold E1Here I do not know , how much current I should inject in the phase monitoring units of the relay. I should ideally spend 50% of the thermal capacity and verify that the relay does not allow me to restart unless the remaining thermal capacity is 60%.6. To check the thermal threshold E2The problem here is similar to the problem mentioned for E17. Startup threshold Is.Inject a current equal to the startup threshold through both the phase monitoring units of the relay connected in series. The relay should pickup after the startup time elapses ( 6 seconds in this case)8 Rotor stall delayInject a current greater than the startup threshold through both the phase monitoring units of the relay connected in series. The relay should pick up after the fixed time delay of 1.6 seconds. Thank u all once again. isoA120 Link to comment Share on other sites More sharing options...
Guest Posted September 29, 2004 Report Share Posted September 29, 2004 hi friends i have a mopn 01 motor protection relay from alstom i need technical manual for this relay you can mail to me to mahde173@yahoo.com thank u all once again Link to comment Share on other sites More sharing options...
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