American Water Heater COMMERCIAL ELECTRIC WATER HEATERS Pre Service Checks, Wiring Connections

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PRE SERVICE CHECKS

PRE SERVICE CHECKS

PRE SERVICE CHECKS

WIRING CONNECTIONS

With the power supply to the water heater turned off ensure the wiring connections are properly tightened to all components including: high voltage terminal blocks, fuse blocks, contactors, transformers and heating elements.

Loose connections at any connection point will cause increased amperage and excessive heat which can damage wiring and components. Whenever worn or damaged wiring and components must be replaced ensure all wiring connections are properly tightened before putting the water heater back in service.

SERVICE PRECAUTIONS

1DO NOT energize the branch circuit supplying power to the water heater or test the water heater electrical system before the water heater is completely filled with water. Read the start up procedures in the Instruction Manual that came with the water heater.

2Be sure to turn off power and use a lock out device at the branch circuit power supply disconnect switch or breaker when servicing the electrical system of the water heater. Never touch electrical components with wet hands or when standing in water.

3When replacing heating elements ensure they are rated at the correct voltage and KW for the water heater being serviced - see Heating Element Ratings and Heating Element Configurations on page 21 and Replacing Heating Elements on page 26.

4When replacing fuses use an insulated fuse puller to remove and install fuses. Always use the correct size for the circuit. See the Replacement Fuses Service Note on page 17 in this manual.

5Using an AC volt meter measure the branch circuit power supply voltage to the water heater. Ensure the measured voltage of the branch circuit supplying power to the water heater matches the water heater’s rating label - see pages 12 - 14.

6Ensure the internal power phase configuration matches the power supply to the water heater. The water heaters covered by this manual are phase convertible - see pages 15 and 16.

7Electronic Control Models covered by this manual are equipped with contactors and will have a multi tap control circuit transformer. This is a step down transformer that outputs 120 VAC (secondary winding) which is used to power the electronic control system and energize the contactor coils. The transformer can accommodate different power supply voltages and has multiple input voltage connections or “taps.” Ensure the input supply voltage (primary winding) wiring to the transformer is connected properly. See page 34 in this manual.

Service Note - Contactor Chatter: Incorrect supply voltage wiring to the multiple tap 120 VAC Control Circuit Transformer on Electronic Control Models will cause low/high output voltage from the transformer. This can cause contactors to open and close their contacts rapidly (contactor chatter) and result in permanent damage to the contactors. Ensure the primary winding of the multiple tap 120 VAC Control Circuit Transformer is wired to match the power supply voltage - see pages 12 -14and page 34.

Servicing should only be performed by a Qualified Service Agent

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Contents Service Handbook COMMERCIAL ELECTRIC WATER HEATERSMODELS STCE3-52/80/119 & ITCE3-52/80/119 Technical Support and PartsPage COMMERCIAL ELECTRIC WATER HEATER TABLE OF CONTENTSSERVICE MANUAL QUALIFICATIONS - QUALIFIED SERVICE AGENT SERVICE WARNINGIMPORTANT SERVICE REMINDER INTRODUCTIONINSTRUCTION MANUAL TOOLS REQUIREDTHERMAL EXPANSION INSTALLATION CONSIDERATIONSCLOSED WATER SYSTEMS Grounding Power SupplyELECTRICAL REQUIREMENTS SERVICE PRECAUTIONS PRE SERVICE CHECKSWIRING CONNECTIONS HEATING ELEMENT CONFIGURATIONS WATER HEATER CONSTRUCTIONSURFACE MOUNT CONTROL MODELS ELECTRONIC CONTROL MODELSSURFACE MOUNT CONTROL MODELS WATER HEATER CONSTRUCTIONELECTRONIC CONTROL MODELS OPERATION & SERVICE PRINCIPLES OF ELECTRICITYVoltage 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 Checking Three Phase 3Ø Power 1 L1 and L2 terminals of the water heater’s Power Distribution Block2 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 Heating Element Configurations NUMBER OF FACTORY INSTALLEDHeating Element Ratings TOTALHeating Element Amperage ELEMENTAPPROXIMATE CURRENT - AMPS 208 VACHeating Element Amperage Test Heating Element Voltage Test Heating Element Resistance & Ground Tests Measuring ResistanceHeating Element Ground Test Replacing Heating ElementsELEMENT SENSORS Element Sensor ConstructionElement Sensor Three Current Sensors Element Sensor FunctionsElement Sensor Operation CONTACTORS Contactor Construction - How They WorkContactor Configurations Power Connection TerminalsElement Numbers/Connections Wire Colors to Elements ContactorsContactor Inspection Physically Operate MechanicalContactor Coil Voltage - At Contactor Contactor Coil Voltage - At CCB 120 VAC Control Circuit Transformer Wiring X1 120 VACTRANSFORMERS 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 Test Temperature Sensor Resistance DataChecking Temperature Sensor Resistance WATER TEMPERATURETemperature Sensor DC Voltage Test ECO Continuity TestChecking ECO Switch Continuity DC Voltage To Temperature SensorECO Voltage Test 120 VAC To ECO120 VAC From ECO Ground ConnectionELECTRONIC CONTROLS UIM User Interface Module CCB Central Control BoardCCB - CENTRAL CONTROL BOARD CCB Socket & Wiring Terminal Identification J2 Socket - 120 VAC Power SupplyJ3 Wiring Terminals - Alarm Output Relay see page J4 Wiring Terminals - Contactor CoilsJ7 Socket - Enable / Disable Circuits 1 & 2 see pages 45 J16 Socket - Not Used J17 Wiring Terminals - Not UsedJ8 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 Service Notes - Button Pad Ribbon Cable UIM - USER INTERFACE MODULEUIM Circuit Board Back UIM Circuit Board FrontCONTROL SYSTEM FEATURES ELECTRONIC CONTROL SYSTEMCONTROL SYSTEM NAVIGATION UIM - User Interface ModuleTHE DESKTOP SCREEN Table 1 Status Icons ICONTable 2 - Operating States Table 3 - Control System MenusSTATE MENUS†Differential Settings TEMPERATURES MENUOperating Set Point Tank TemperatureTemperature Settings Enable / Disable 1 Alarm ConditionAlarm Relay Output HEATER STATUS MENUECONOMY MODE SETUP MENU Setpoint AdjustmentDesktop 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 ALARM OUTPUT SETUP MENU Temp Alarm SP Used for externalAlarm SP Alarm Output SettingsDISPLAY SETTINGS MENU Display SettingsTemperature Units Backlight DelayHEATER INFORMATION MENU Elapsed TimeTotal Heating Time Bank # CyclesCURRENT FAULT / ALERT MENU FAULT HISTORY MENUFAULT OCCURRENCE MENU Main Menu - Current Fault Selected Fault History MenuFactory Default User Settings RESTORE FACTORY DEFAULTS MENURestore Factory Defaults TROUBLESHOOTING COMMON SERVICE PROBLEMSNo Hot Water Not Enough Hot WaterFault Conditions Resetting Control SystemCONTROL SYSTEM UNRESPONSIVE 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
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