American Water Heater STCE3-52/80/119, ITCE3-52/80/119 manual X1 120 VAC, Transformers

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TRANSFORMERS

OPERATION & SERVICE

TRANSFORMERS

This section of the manual provides information on how to test and ensure the multiple tap 120 VAC Control Circuit Transformer is wired properly on Electronic Control Models. This section will also provide test procedures for the 24 VAC transformer used by the electronic control system - see Figure 2 on page 9 for location of the transformers on these models. Surface Mount Control Models are not equipped with transformers.

120 VAC Control Circuit Transformer Wiring

The 120 VAC Control Circuit transformer is a multiple or “multi” tap transformer that can accept 4 different input voltages to it’s primary winding. See Figure 2 on page 9 for location. This transformer outputs 120 VAC power from it’s secondary winding which powers the CCB circuit board and the contactor coils. The input power wiring to the primary winding of this transformer must be configured to match the power supplied to the water heater. Incorrect wiring can cause output voltage from the transformer’s secondary winding to be too low or too high. This can cause “contactor chatter” (contacts open and close rapidly) and may permanently damage the contactors and/or the CCB circuit board. The table and illustrations that follow show how to properly configure the input power wiring to the transformers primary winding.

1Only one wire need be changed on the transformer to change voltage. Do not move or change the wire to the common H1 connection on the primary winding or either wire to the secondary winding X1 or X2 connections. Remove the wire from the terminal marked H2 208, H3 240, H4 277 or H5 480 and attach it to the appropriate terminal that matches the water heater’s power supply voltage.

WATER HEATER POWER SUPPLY VOLTAGE	PRIMARY WINDING CONNECTIONS

208 VAC	H1 Common & H2 (208)

240 VAC	H1 Common & H3 (240)

277 VAC	H1 Common & H4 (277)

480 VAC	H1 Common & H5 (480)

H1 H2 H3 H4 H5 N/A

Primary Winding

Secondary Winding

X1 X2

120 VAC

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 TABLE OF CONTENTS SERVICE MANUALCOMMERCIAL ELECTRIC WATER HEATER QUALIFICATIONS - QUALIFIED SERVICE AGENT SERVICE WARNINGIMPORTANT SERVICE REMINDER INTRODUCTIONINSTRUCTION MANUAL TOOLS REQUIREDINSTALLATION CONSIDERATIONS CLOSED WATER SYSTEMSTHERMAL EXPANSION Power Supply ELECTRICAL REQUIREMENTSGrounding PRE SERVICE CHECKS WIRING CONNECTIONSSERVICE PRECAUTIONS 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 AmperageOhms Law applied to “SINGLE PHASE” 1Ø power Ohms LawCalculating Amps/Ohms/Volts/Watts 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 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 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 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 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 Power and Ground To The CCB Checking for 120 VACChecking for Ground 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 Economy Mode Settings Daily Operating Mode Settings Economy Mode All DayNormal Operation Between 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 MenuRESTORE FACTORY DEFAULTS MENU Restore Factory DefaultsFactory Default User Settings TROUBLESHOOTING COMMON SERVICE PROBLEMSNo Hot Water Not Enough Hot WaterFault Conditions Resetting Control SystemCONTROL SYSTEM UNRESPONSIVE Alert ConditionsHeating Cycle Disabled Control System Unresponsive contUIM is Inoperable FAULT AND ALERT MESSAGES “No Current Detected”Fault & Alert Messages “Temp Probe Open”“Temp Probe Short” “Energy Cut Out ECO” Page Page Page Page Technical Support and Parts