American Water Heater COMMERCIAL ELECTRIC WATER HEATERS manual Temperature Sensor DC Voltage Test

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Temperature Sensor DC Voltage Test

OPERATION & SERVICE

Temperature Sensor DC Voltage Test

1Ensure the main breaker or disconnect switch is turned on.

2Verify the CCB circuit board has the correct input voltage at the J2 socket and is properly grounded - perform the “Checking Power and Ground To The CCB” tests on page 46.

3Unplug the J5 plug from the CCB circuit board (note: the control system will lock out and display “Temp Probe Open” Fault message on the UIM when the J5 plug is removed - cycle power off and reinstall J5 plug when tests are complete). Using a “DC” (direct current) volt meter check for DC voltage between pins 2 & 3 of the J5 socket as shown in the “DC Voltage To Temperature Sensor” image below.

If the measured voltage is 5 VDC the temperature sensor is being powered correctly. If there is not 5 VDC call the toll free Technical Support phone number listed on the back cover of this manual for further assistance.

ECO Continuity Test

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

2Unplug the J5 plug from the CCB circuit board - see page 42 for location.

3Ensure tank temperature is less than 100°F/38°C - dump water to lower tank temperature if necessary.

4Using an ohm meter; set the Ohm meter to it’s lowest resistance range (< 200) or to an audible beep continuity test setting if so equipped.

5Touch the ohm meter probes between the two outside pins (red wires) of the J5 plug end as shown in the “Checking ECO Switch Continuity” image below.

If the ohm meter shows continuity (closed circuit) between the two outside pins (red wires) of the J5 plug end the ECO switch has reset properly. If the control system continues to lock out displaying the “Energy Cut Out (ECO)” Fault message with continuity through the ECO present call the toll free Technical Support phone number listed on the back cover of this manual for further assistance.

If the ohm meter shows no continuity (open circuit) between the two outside pins (red wires) of the J5 plug end and the control system and the tank temperature is known to be at or below 100°F/38°C - replace the Immersion Temperature Probe. Secure power to the water heater and drain the water heater before replacing the probe.

If the control system continues to lock out displaying the “Energy Cut Out (ECO)” Fault message and the water temperature inside the water heater is becoming excessive (at or above 202°F/94°C) check contactors (pages 29 - 32) to ensure they are not stuck closed and check for voltage at all heating elements (page 24) during the standby mode. Check water system piping; ensure heat is not being added to the water inside the water heater being serviced by any other heating appliances or heat sources. If all these tests have been performed and the control system continues to lock out displaying the “Energy Cut Out (ECO)” Fault message call the toll free Technical Support phone number listed on the back cover of this manual for further assistance.

DC Voltage To Temperature Sensor

Checking ECO Switch Continuity

 

 

 

 

 

 

 

 

 

 

Servicing should only be performed by a Qualified Service Agent

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Contents COMMERCIAL ELECTRIC WATER HEATERS Service HandbookMODELS STCE3-52/80/119 & ITCE3-52/80/119 Technical Support and PartsPage COMMERCIAL ELECTRIC WATER HEATER TABLE OF CONTENTSSERVICE MANUAL SERVICE WARNING QUALIFICATIONS - QUALIFIED SERVICE AGENTIMPORTANT SERVICE REMINDER INTRODUCTIONTOOLS REQUIRED INSTRUCTION MANUALTHERMAL EXPANSION INSTALLATION CONSIDERATIONSCLOSED WATER SYSTEMS Grounding Power SupplyELECTRICAL REQUIREMENTS SERVICE PRECAUTIONS PRE SERVICE CHECKSWIRING CONNECTIONS WATER HEATER CONSTRUCTION HEATING ELEMENT CONFIGURATIONSSURFACE MOUNT CONTROL MODELS ELECTRONIC CONTROL MODELSWATER HEATER CONSTRUCTION SURFACE MOUNT CONTROL MODELSWATER HEATER CONSTRUCTION PRINCIPLES OF ELECTRICITY OPERATION & SERVICEVoltage AmperageCalculating Amps/Ohms/Volts/Watts Ohms Law applied to “SINGLE PHASE” 1Ø powerOhms Law L1 L2 L3 SINGLE AND THREE PHASE POWERChecking Single Phase 1Ø Power 1 L1 and L2 terminals of the water heater’s Power Distribution Block Checking Three Phase 3Ø Power2 L2 and L3 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 NUMBER OF FACTORY INSTALLED Heating Element ConfigurationsHeating Element Ratings TOTALELEMENT Heating Element AmperageAPPROXIMATE CURRENT - AMPS 208 VACHeating Element Amperage Test Heating Element Voltage Test Measuring Resistance Heating Element Resistance & Ground TestsReplacing Heating Elements Heating Element Ground TestElement Sensor Construction ELEMENT SENSORSElement Sensor Three Current Sensors Element Sensor FunctionsElement Sensor Operation Contactor Construction - How They Work CONTACTORSPower Connection Terminals Contactor ConfigurationsElement Numbers/Connections Wire Colors to Elements ContactorsPhysically Operate Mechanical Contactor InspectionContactor Coil Voltage - At Contactor Contactor Coil Voltage - At CCB X1 120 VAC 120 VAC Control Circuit Transformer WiringTRANSFORMERS 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 Temperature Sensor Resistance Data Temperature Sensor Resistance TestChecking Temperature Sensor Resistance WATER TEMPERATUREECO Continuity Test Temperature Sensor DC Voltage TestChecking ECO Switch Continuity DC Voltage To Temperature Sensor120 VAC To ECO ECO Voltage Test120 VAC From ECO Ground ConnectionUIM User Interface Module CCB Central Control Board ELECTRONIC CONTROLSCCB - CENTRAL CONTROL BOARD J2 Socket - 120 VAC Power Supply CCB Socket & Wiring Terminal IdentificationJ3 Wiring Terminals - Alarm Output Relay see page J4 Wiring Terminals - Contactor CoilsJ16 Socket - Not Used J17 Wiring Terminals - Not Used J7 Socket - Enable / Disable Circuits 1 & 2 see pages 45J8 Socket - Not Used J9 Socket - Not Used J10 Socket - 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 - USER INTERFACE MODULE Service Notes - Button Pad Ribbon CableUIM Circuit Board Back UIM Circuit Board FrontELECTRONIC CONTROL SYSTEM CONTROL SYSTEM FEATURESCONTROL SYSTEM NAVIGATION UIM - User Interface ModuleTHE DESKTOP SCREEN ICON Table 1 Status IconsTable 3 - Control System Menus Table 2 - Operating StatesSTATE MENUS†TEMPERATURES MENU Differential SettingsOperating Set Point Tank TemperatureTemperature Settings Alarm Condition Enable / Disable 1Alarm Relay Output HEATER STATUS MENUSetpoint Adjustment ECONOMY MODE SETUP MENUDesktop Screen During Economy Mode Economy Mode Setup Menu 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 Temp Alarm SP Used for external ALARM OUTPUT SETUP MENUAlarm SP Alarm Output SettingsDisplay Settings DISPLAY SETTINGS MENUTemperature Units Backlight DelayElapsed Time HEATER INFORMATION MENUTotal Heating Time Bank # CyclesFAULT HISTORY MENU CURRENT FAULT / ALERT MENUFAULT OCCURRENCE MENU Main Menu - Current Fault Selected Fault History MenuFactory Default User Settings RESTORE FACTORY DEFAULTS MENURestore Factory Defaults COMMON SERVICE PROBLEMS TROUBLESHOOTINGNo Hot Water Not Enough Hot WaterResetting Control System Fault ConditionsCONTROL SYSTEM UNRESPONSIVE Alert ConditionsUIM is Inoperable Heating Cycle DisabledControl System Unresponsive cont “No Current Detected” FAULT AND ALERT MESSAGES“Temp Probe Short” Fault & Alert Messages“Temp Probe Open” “Energy Cut Out ECO” Page Page Page Page Technical Support and Parts