MiCOM P921/P922/P923 - Schneider - error

P92x/EN CM/F22Page 22/26Commissioning GuideMiCOM P921/P922/P9236. ON-LOAD CHECKS - VOLTAGE INPUT CONNECTIONSThe following on-load measuring checks ensure the external wiring to the voltage inputs iscorrect but can only be carried out if there are no restrictions preventing the energisation ofthe plant being protected.REMOVE ALL TEST LEADS, TEMPORARY SHORTING LEADS, ETC. AND REPLACEANY EXTERNAL WIRING THAT HAS BEEN REMOVED TO ALLOW TESTING.IF IT HAS BEEN NECESSARY TO DISCONNECT ANY OF THE EXTERNAL WIRINGFROM THE RELAY IN ORDER TO PERFORM ANY OF THE FOREGOING TESTS, ITSHOULD BE ENSURED THAT ALL CONNECTIONS ARE REPLACED IN ACCORDANCEWITH THE RELEVANT EXTERNAL CONNECTION OR SCHEME DIAGRAM.USING A MULTIMETER, MEASURE THE VOLTAGE TRANSFORMER SECONDARYVOLTAGES TO ENSURE THEY ARE CORRECTLY RATED. CHECK THAT THE SYSTEMPHASE ORDER IS CORRECT USING A PHASE METER.COMPARE THE VALUES OF THE SECONDARY PHASE VOLTAGES WITH THERELAY'S MEASURED VALUES, WHICH CAN BE FOUND IN THE MEASUREMENTSMENU.The values measured by the MiCOM relay should be within 1% of the applied primaryvoltages. However, an additional allowance must be made for the accuracy of the testequipment being used.