Eaton CUTLER-HAMMER MD-3000 series Installation, Operation And Maintanance

For more information visit: www.EatonElectrical.comInitial ReleaseSECTION 3: OPERATION3-1 INTRODUCTIONThis section specifically describes the operation andfunctional use of the MD-3000 Protective Relay. It doesnot address in detail rear power connections. This iscovered in SECTION 5 entitled “INSTALLATION,STARTUP AND TESTING.” It would be helpful to becomefamiliar with the relay’s wiring diagram before proceedingwith the rest of this section (Figure 3-1).3-2 POWER-UP AND SELF TESTINGWhen the proper ac or dc control voltage is applied topower supply input terminals, the unit will initiate a “PowerOn Reset” to its chip circuitry. This causes the unit’sfirmware to perform some self-testing and initialization ofits ROM, RAM and E2 (non-volatile) memory. If anyproblem exists, a diagnostic message will be displayed inthe Settings/Test Time/Trip Cause Window. A complete listof messages and their meanings are listed in Table 3.2.Additionally, if a problem does exist, the “Operational LED”will light red and the “Protection Off Alarm” relay will notenergize. When all self checks are good the “OperationalLED” will blink green.3-3 PANEL OPERATIONSBegin by reviewing the material presented in SECTION 2entitled “FUNCTIONAL DESCRIPTION.” Since basicdefinitions and explanations were given in SECTION 2, nofurther explanation as to function will be offered in thissection. It is assumed that the operator is now familiar withMD-3000 terms, available settings and overall capabilities.3-3.2 PROGRAM MODEMD-3000 PROTECTIVE RELAY SETTINGS MUSTBE PROGRAMMED BEFORE THE RELAY IS PUTINTO OPERATION. CARE MUST BE TAKEN WHENPROGRAMMING THE MD-3000 WHILE THEBREAKER IS CLOSED AND CURRENT ISFLOWING. AN INCORRECT SETTINGCONFIGURATION COULD CAUSE THE RELAY TOTRIP THE BREAKER WHEN SETTINGS ARESAVED.Notes:1. The settings that are altered during a programmingsession will not be saved until the Save Settingspushbutton is pressed and released.2. When programming is concluded and new set pointssaved, the Program Mode pushbutton should bepressed and released to exit the Program Mode.3. The Program Mode is also exited if the Resetpushbutton is pressed and released or if there is noprogramming activity for approximately 2-1/2 minutes.To enter the Program Mode, open the protective accesscover and press and release the Program Mode On/Offpushbutton. The Program LED will blink green, indicatingthat the Program Mode has been entered. The presentvalue of the first set point to be programmed (DifferentialPickup) will appear in the Settings/Test Time/Trip CauseWindow, which will be referred to as the Alpha-numericDisplay for the rest of this discussion. The DifferentialPickup LED will be blinking green. The Raise or Lowerpushbuttons can now be used to change the value of theset point. Keep in mind that the Raise and Lowerpushbuttons will roll over from highest to lowest and lowestto highest respectively. If either of the pushbuttons is helddown and not released, their function is accelerated. Thisis true for all white pushbuttons on the panel face.Pressing and releasing the Select Settings pushbutton willcause the unit to step to the next set point. This is theTime setting. The Time LED will blink green.After the Raise and/or Lower pushbuttons are used toarrive at the desired Time setting, the Select Settingspushbutton can be pressed and released to step to thenext set point, which is the Frequency setting.When this selection is made and the Select Settingspushbutton is pressed and released, the relay steps to thePhase CT Ratio Setting.The programmed value for the phase CT will appear in thealphanumeric display. Once this selection is made andprogrammed, the Select Settings pushbutton is pressedand released to move to the last set point.To save the new settings at any time, press and releasethe Save Settings pushbutton. When the Save Settingspushbutton is pressed and released, the unit will blank thealphanumeric display for two seconds, and then displaythe last setting. At this moment, the unit will use the newset points for protection. After pressing the Save Settingspushbutton, the Program Mode can be exited by any oneof three ways:1. Press and release the Program Mode On/Offpushbutton.2. Press and release the Reset pushbutton.3. Perform no programming activity for 2 1/2 minutes.THE SAVE SETTINGS PUSHBUTTON MUST BEPRESSED AND RELEASED BEFORE EXITINGTHE PROGRAM MODE. OTHERWISE, THECHANGED SETPOINTS WILL NOT BE SAVED. INADDITION, AFTER THE PROGRAMMING OFSETTINGS IS COMPLETE, IT IS VERYIMPORTANT TO VERIFY ALL THE SETTINGS BYDEPRESSING THE “VIEW SETTINGS”PUSHBUTTON AND STEPPING THROUGH THESETTINGS.