American Water Heater COMMERCIAL ELECTRIC WATER HEATERS manual Heating Element Voltage Test

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Heating Element Voltage Test

OPERATION & SERVICE

Heating Element Voltage Test

This test is typically performed after an amperage test (see page 23) has determined one or more heating elements is not drawing correct amperage.

1Secure power to the water heater at the main breaker or disconnect switch.

2Ensure tank temperature is less than 100°F/38°C - dump water to lower tank temperature if necessary.

3Surface Mount Control Models - raise the temperature settings to ensure a call heat is active for all heating elements. Press the red reset button firmly on all thermostat/ECO controls then raise the temperature setting on all thermostat/ECO controls to 140°F or higher - see page 18.

4Restore power to the water heater.

5Electronic Control Models - adjust the temperature settings to ensure a call heat is active for all heating elements. Raise the Operating Set Point in the Temperatures Menu to 140°F or higher. Set all Heating Element Bank Differentials in the Temperatures Menu to 2°F - see pages 52 and 53.

6Using an AC volt meter; set the volt meter to an AC voltage range above the expected voltage (600 VAC or higher range initially).

7Check voltage between the two terminals on the heating element - see the image below. Record the voltage at all heating elements. Voltage should match the listed voltage on the water heater’s rating label.

8If the measured voltage is zero volts or is not the correct voltage - check power to the water heater (pages 12 - 14), check fuses (page 17). Ensure heating element power circuit wiring is correct (see wiring diagram on water heater). Check thermostat/ECO control(s) supplying power to the heating element on Surface Mount Control models - see page 19. Check contactors on Electronic Control Models (see pages 29 - 33). Check all wiring and connections between the heating elements, contactors, fuses and the power distribution block. Ensure all wiring and connections are tight and making good contact - replace any wiring, fuses and/or contactors that are not working properly, damaged or show signs of excessive wear.

Measuring voltage on an electric heating element. Touch the two volt meter probes to the two terminals on the end of each heating element.

DO NOT TOUCH THE ENDS OF ANY

HEATING ELMENTS WHILE PERFORMING

THIS TEST

Be extremely careful as there will be high voltage present at the wiring terminals on all heating elements during this test.

Servicing should only be performed by a Qualified Service Agent

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Contents MODELS STCE3-52/80/119 & ITCE3-52/80/119 Service HandbookCOMMERCIAL ELECTRIC WATER HEATERS Technical Support and PartsPage COMMERCIAL ELECTRIC WATER HEATER TABLE OF CONTENTSSERVICE MANUAL IMPORTANT SERVICE REMINDER QUALIFICATIONS - QUALIFIED SERVICE AGENTSERVICE WARNING INTRODUCTIONINSTRUCTION MANUAL TOOLS REQUIREDTHERMAL EXPANSION INSTALLATION CONSIDERATIONSCLOSED WATER SYSTEMS Grounding Power SupplyELECTRICAL REQUIREMENTS SERVICE PRECAUTIONS PRE SERVICE CHECKSWIRING CONNECTIONS SURFACE MOUNT CONTROL MODELS HEATING ELEMENT CONFIGURATIONSWATER HEATER CONSTRUCTION ELECTRONIC CONTROL MODELSSURFACE MOUNT CONTROL MODELS WATER HEATER CONSTRUCTIONELECTRONIC CONTROL MODELS Voltage OPERATION & SERVICEPRINCIPLES OF ELECTRICITY AmperageCalculating Amps/Ohms/Volts/Watts Ohms Law applied to “SINGLE PHASE” 1Ø powerOhms Law SINGLE AND THREE PHASE POWER L1 L2 L3Checking Single Phase 1Ø Power 2 L2 and L3 terminals of the water heater’s Power Distribution Block Checking Three Phase 3Ø Power1 L1 and L2 terminals of the water heater’s Power Distribution Block 3 L1 and L3 terminals of the water heater’s Power Distribution BlockSurface Mount Control Models Single Phase to Three Phase PHASE CONVERSIONS - SURFACE MOUNT CONTROL MODELSSurface Mount Control Models Three Phase to Single Phase Electronic Control Models Single Phase to Three Phase PHASE CONVERSIONS - ELECTRONIC CONTROL MODELSElectronic Control Models Three Phase to Single Phase Volt Meter Method FUSESOhm Meter Method SURFACE MOUNT THERMOSTATS Thermostat & ECO Test Wire conductor inside tube HEATING ELEMENTSHeating Element Construction Heating Element Ratings Heating Element ConfigurationsNUMBER OF FACTORY INSTALLED TOTALAPPROXIMATE CURRENT - AMPS Heating Element AmperageELEMENT 208 VACHeating Element Amperage Test Heating Element Voltage Test Heating Element Resistance & Ground Tests Measuring ResistanceHeating Element Ground Test Replacing Heating ElementsElement Sensor ELEMENT SENSORSElement Sensor Construction Three Current Sensors Element Sensor FunctionsElement Sensor Operation CONTACTORS Contactor Construction - How They WorkElement Numbers/Connections Wire Colors to Elements Contactor ConfigurationsPower Connection Terminals ContactorsContactor Inspection Physically Operate MechanicalContactor Coil Voltage - At Contactor Contactor Coil Voltage - At CCB TRANSFORMERS 120 VAC Control Circuit Transformer WiringX1 120 VAC H1 H2 H3 H4 H5 N/A Primary Winding Secondary WindingSecondary Winding Voltage Test 120 VAC Control Circuit Transformer TestPrimary Winding Voltage Test 24 VAC Transformer Test Temperature Sensor ECO High Temperature Limit SwitchIMMERSION TEMPERATURE PROBE Checking Temperature Sensor Resistance Temperature Sensor Resistance TestTemperature Sensor Resistance Data WATER TEMPERATUREChecking ECO Switch Continuity Temperature Sensor DC Voltage TestECO Continuity Test DC Voltage To Temperature Sensor120 VAC From ECO ECO Voltage Test120 VAC To ECO Ground ConnectionELECTRONIC CONTROLS UIM User Interface Module CCB Central Control BoardCCB - CENTRAL CONTROL BOARD J3 Wiring Terminals - Alarm Output Relay see page CCB Socket & Wiring Terminal IdentificationJ2 Socket - 120 VAC Power Supply J4 Wiring Terminals - Contactor CoilsJ8 Socket - Not Used J9 Socket - Not Used J10 Socket - Not Used J7 Socket - Enable / Disable Circuits 1 & 2 see pages 45J16 Socket - Not Used J17 Wiring Terminals - Not Used J13 Socket - Heating Element Sensors BankCCB Enable/Disable Circuits Test Checking for Ground Checking Power and Ground To The CCBChecking for 120 VAC UIM Circuit Board Back Service Notes - Button Pad Ribbon CableUIM - USER INTERFACE MODULE UIM Circuit Board FrontCONTROL SYSTEM NAVIGATION CONTROL SYSTEM FEATURESELECTRONIC CONTROL SYSTEM UIM - User Interface ModuleTHE DESKTOP SCREEN Table 1 Status Icons ICONSTATE Table 2 - Operating StatesTable 3 - Control System Menus MENUS†Operating Set Point Differential SettingsTEMPERATURES MENU Tank TemperatureTemperature Settings Alarm Relay Output Enable / Disable 1Alarm Condition HEATER STATUS MENUDesktop Screen During Economy Mode Economy Mode Setup Menu ECONOMY MODE SETUP MENUSetpoint Adjustment Current TimeEconomy Mode Settings Setpoint Adjustment Value Economy Mode Settings Time Clock Settings Normal Operation Between Economy Mode Settings Daily Operating Mode SettingsEconomy Mode All Day Alarm SP ALARM OUTPUT SETUP MENUTemp Alarm SP Used for external Alarm Output SettingsTemperature Units DISPLAY SETTINGS MENUDisplay Settings Backlight DelayTotal Heating Time HEATER INFORMATION MENUElapsed Time Bank # CyclesFAULT OCCURRENCE MENU CURRENT FAULT / ALERT MENUFAULT HISTORY MENU Main Menu - Current Fault Selected Fault History MenuFactory Default User Settings RESTORE FACTORY DEFAULTS MENURestore Factory Defaults No Hot Water TROUBLESHOOTINGCOMMON SERVICE PROBLEMS Not Enough Hot WaterCONTROL SYSTEM UNRESPONSIVE Fault ConditionsResetting Control System Alert ConditionsUIM is Inoperable Heating Cycle DisabledControl System Unresponsive cont FAULT AND ALERT MESSAGES “No Current Detected”“Temp Probe Short” Fault & Alert Messages“Temp Probe Open” “Energy Cut Out ECO” Page Page Page Page Technical Support and Parts