Eaton ATC-300 O & M Manual

Also see for Cutler-Hammer ATC-300: Instruction booklet Operation and maintenance manual Instruction booklet Instruction booklet O & M Manual

IB01602015E For more information visit: www.eaton.comInstruction BookletEffective: August 2010 Page 21ATC-300 2-Postion Contactor Based Transfer Switch5.3 Automatic TransferThe operating sequence of an ATS is dictated by the switch'sstandard features and selected options. Operation of an ATSduring Source 1 power source failure and Source 1 power sourcerestoration will be described here with only standard optionsincluded on the switch. Additional options, as described in Sec-tion 3, can change sequences and timing, depending upon theoptions selected. It is strongly suggested that you become famil-iar with additional options selected with the particular ATS andtheir effect on the normal operation of an ATS.5.3.1 Source 1 Power Source FailureStandard Source 1 power source failure is defined as a reductionor loss of voltage. If this occurs, the sequence of operation is asfollows.1. Failure of Source 1 is detected by the controller intelligence.2. When the controller detects a failure, the engine contactsclose (after delay if programmed) and start the engine-drivengenerator.3. When the Source 2 voltage reaches its operation rating, theK2 relay closes, starting the transfer operation. This operat-ing sequence causes the contactor to open Source 1 andclose on Source 2.4. The load is now transferred to the Source 2 power source.5.3.2 Source 1 Power Source Restoration1. A return to the Source 1 power source begins when the volt-age in all phases of a 3-phase sensing unit, or phase-to-phase in a single sensing unit, is restored to a preset value.2. At the preset voltage, the controller will cause the K1 relayto change state. This starts the return to the Source 1power source.3. During this sequence, the contactor opens Source 2 andcloses on Source 1.4. Simultaneously, the engine cool-down timer initiates the shutdown of the engine driven generator.5. Transfer of the load back to the Source 1 power source isnow complete.Section 6: Testing and Problem Solving6.1 TestingAfter the ATS equipment is initially installed or during plannedoutages, the installation should be tested to ensure that all equip-ment operates properly. This attention to detail will help avoidunexpected malfunctions. Mechanical and/or electrical testsshould be performed as described in this section.The frequency of subsequent testing should be based on recom-mendations of the Genset manufacturer. Use the test pushbut-ton to check the electrical operation of the switch.6.1.1 Mechanical and/or Electrical TestingEnergize the ATS equipment as described in Sections 6.1.2through 6.1.6. Insure that all safety precautions are taken andthat all WARNINGS and CAUTIONS are observed.6.1.2 No Voltage StepsWith no voltage available on either power source, proceed as fol-lows.Step 1: The generator engine start controls should be in the OFFposition to prevent an undesired start.Step 2: Ensure that the ATS has been set to the proper appliedsystem voltage (See Section 4.7).Step 3: Check all ATS loads to ensure that they are ready to beenergized.6.1.3 Connecting the Power SourcesStep 1: Close the Source 1 power source upstream protectiondevice.Step 2: Connect the engine start battery cable.Step 3: With the emergency generator in the OFF position, closethe Source 2 power source upstream protective device,assuming such a device used.WARNINGHIGH VOLTAGES ASSOCIATED WITH OPERATIONAL TRANSFERSWITCH EQUIPMENT PRESENT A SHOCK HAZARD THAT CANCAUSE SEVERE PERSONAL INJURY OR DEATH. USE EXTREMECAUTION TO AVOID TOUCHING ELECTRICAL CONNECTIONSWHENEVER INSPECTING OR TESTING THE EQUIPMENT.IN ADDITION, IMPROPER OPERATION OF THE GENERATOR SETPRESENTS A HAZARD THAT CAN CAUSE SEVERE PERSONALINJURY OR DEATH. OBSERVE ALL SAFETY PRECAUTIONS IN YOURGENERATOR SET OPERATIONS AND INSTALLATION MANUALS.NOTICESINCE FEATURE 4 (TIME DELAY ENGINE COOL-OFF), ASDESCRIBED IN SECTION 3, IS A STANDARD FEATURE, AN ENGINESTART SIGNAL WILL BE PRESENT FOR A PERIOD OF TIME WHENTHE SWITCH IS FIRST ENERGIZED. THE PERIOD OF TIME IS EQUALTO THE TIMER SETTING. TO AVOID STARTING THE ENGINE DUR-ING THIS TIME PERIOD, TURN THE GENERATOR CONTROLS TOTHE OFF POSITION.