ABB ret650 Commissioning Manual

Also see for ret650: Applications manual Commissioning manual Commissioning manual Product guide Applications manual

Contents

1. The test above can be repeated to check a positive setting of StartFreqGrad.2. The tests above can be repeated to test the RESTORE signal, when thefrequency recovers from a low value.6.6.3.2 Completing the testContinue to test another function or end the testing by setting the parameterTestMode to Off under Main menu/Tests/IED test mode/1:TESTMODE. Ifanother function is tested, then set the parameter Blocked to No under Main menu/Tests/Function test modes/Frequency/SAPFRC(81,df/dt)/X:SAPFRC for thefunction, or for each individual function in a chain, to be tested next. Remember toset the parameter Blocked to Yes, for each individual function that has been tested.6.7 Testing control functionsThe save of persistent parts of function block states/values topersistent memory uses an exponential back-off algorithm, whichrapidly increases the time between save operations when there arefrequent changes in such states/values. This means, that when e.g. apulse counter is exercised periodically, the time between saves ofits counter value to persistent memory will occur more and moreseldom until there is one hour between save operations. If the IEDis restarted by turning auxiliary power off and back on, then up toone hour of counter value increments will be lost. This back-offalgorithm is necessary to avoid wearing out the FLASH memorythat is used to save the states/values. When changing parametervalues using LHMI or PST, there is a save of this type of memorybefore rebooting, so in this case normally no information is lost.When there are long periods of inactivity, the time between saveoperations decreases slowly again, until it reaches the minimumtime between saves, which is approximately once per second. Aftercommissioning is complete, the possible loss of information shouldnot be an issue, since in normal operation an IED is switched offextremely seldom. But during certain tests, if the IED is rebooted,then data of this kind will sometimes revert back to old values.6.7.1 Voltage controlPrepare the IED for verification of settings as outlined in 5.1 "Preparing the IED toverify settings".Values of the logical signals for TCMYLTC are available on the local HMI underMain menu/Tests/Function status/Control/TCMYLTC(84)/X:TCMYLTC. The1MRK 504 126-UEN - Section 6Testing functionality65Commissioning Manual