American Water Heater STCE3-52/80/119 Water Heater Construction, Surface Mount Control Models

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WATER HEATER CONSTRUCTION

WATER HEATER CONSTRUCTION

WATER HEATER CONSTRUCTION

There are two types of commercial electric water heaters covered in this manual. See Figure 1 on page 8 and Figure 2 on page 9.

SURFACE MOUNT CONTROL MODELS

The first type of water heater covered in this manual is equipped with surface mount thermostat/ECO controls - Surface Mount Control Models. There will be separate thermostat/ECO (energy cut out) combination controls mounted to the surface of the storage tank directly above the heating elements they control. IE: a water heater equipped with 9 heating elements will have 9 combination thermostat/ECO controls. These combination thermostat/ECO controls sense temperature directly from the surface of the storage tank. Each combination control will have a temperature setting adjustment screw. As the tank (water) temperature rises and falls each individual thermostat will de-energize and energize one heating element according to it’s temperature setting.

ELECTRONIC CONTROL MODELS

The second type of water heater covered in this manual is equipped with an electronic control system - Electronic Control Models. The control system senses temperature electrically from an Immersion Temperature Probe. The probe is installed in a threaded opening in the storage tank (wet well) and senses water temperature directly. As the stored water temperature rises and falls the control system de-energizes and energizes Banks of 3 heating elements indirectly using electromagnetic contactors. The control system energizes the electromagnetic contactor’s (120 VAC) coil causing the switch contacts of the contactor to close which in turn supplies power to the heating elements.

HEATING ELEMENT CONFIGURATIONS

Both types of water heaters covered in this manual are factory equipped with either 3, 6 or 9 heating elements depending on how they were ordered from the factory - see the Heating Element Configurations table on page 21. Each group of 3 heating elements (physically installed in diagonal rows of 3) is referred to as a “Bank” of heating elements. Bank 1 is the lowest group of 3 heating elements, Bank 2 is the middle group of 3 heating elements and Bank 3 is the upper group of 3 heating elements. See Figure 1 on page 8 and Figure 2 on page 9.

Heating Element Voltage and KW Conversion Kits

Voltage and heating element KW conversion kits are available for the water heaters covered in this manual. Voltage and KW conversions are not covered in this manual. Voltage and KW conversion kits with instructions are available from local distributors and can be ordered from the manufacturer’s parts department by calling the toll free number listed on the back cover of this manual. Have the complete model and serial number along with the listed voltage and input KW from the rating label of the water heater on hand before calling.

Service Note: There are field conversion kits to increase/decrease KW input and change voltage. However, conversion kits do not allow adding heating elements to a water heater. Water heaters must remain as they were configured with 3, 6 or 9 heating elements from the factory. HEATING ELEMENTS CANNOT BE ADDED TO A WATER HEATER.

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 TABLE OF CONTENTS SERVICE MANUALCOMMERCIAL ELECTRIC WATER HEATER SERVICE WARNING QUALIFICATIONS - QUALIFIED SERVICE AGENTIMPORTANT SERVICE REMINDER INTRODUCTIONTOOLS REQUIRED INSTRUCTION MANUALINSTALLATION CONSIDERATIONS CLOSED WATER SYSTEMSTHERMAL EXPANSION Power Supply ELECTRICAL REQUIREMENTSGrounding PRE SERVICE CHECKS WIRING CONNECTIONSSERVICE PRECAUTIONS 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 AmperageOhms Law applied to “SINGLE PHASE” 1Ø power Ohms LawCalculating Amps/Ohms/Volts/Watts 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 BlockPHASE CONVERSIONS - SURFACE MOUNT CONTROL MODELS Surface Mount Control Models Three Phase to Single PhaseSurface Mount Control Models Single Phase to Three Phase PHASE CONVERSIONS - ELECTRONIC CONTROL MODELS Electronic Control Models Three Phase to Single PhaseElectronic Control Models Single Phase to Three Phase FUSES Ohm Meter MethodVolt Meter Method SURFACE MOUNT THERMOSTATS Thermostat & ECO Test HEATING ELEMENTS Heating Element ConstructionWire conductor inside tube 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 Winding120 VAC Control Circuit Transformer Test Primary Winding Voltage TestSecondary Winding Voltage Test 24 VAC Transformer Test ECO High Temperature Limit Switch IMMERSION TEMPERATURE PROBETemperature Sensor 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 Power and Ground To The CCB Checking for 120 VACChecking for Ground 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 Economy Mode Settings Daily Operating Mode Settings Economy Mode All DayNormal Operation Between 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 MenuRESTORE FACTORY DEFAULTS MENU Restore Factory DefaultsFactory Default User Settings COMMON SERVICE PROBLEMS TROUBLESHOOTINGNo Hot Water Not Enough Hot WaterResetting Control System Fault ConditionsCONTROL SYSTEM UNRESPONSIVE Alert ConditionsHeating Cycle Disabled Control System Unresponsive contUIM is Inoperable “No Current Detected” FAULT AND ALERT MESSAGESFault & Alert Messages “Temp Probe Open”“Temp Probe Short” “Energy Cut Out ECO” Page Page Page Page Technical Support and Parts
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