American Water Heater STCE3-52/80/119 manual Contactor Inspection, Physically Operate Mechanical

Page 33
Contactor Inspection

OPERATION & SERVICE

Contactor Inspection

A thorough visual inspection of the contactors used on Electronic Control Models should be performed as part of any regular maintenance program and whenever the water heater is being serviced. Refer to the listed Steps and images below for this procedure.

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

2Verify with an AC volt meter that there is not any voltage present at the Power Distribution Block, power circuit fuse block and all wiring terminals on the contactors. See Figure 2 on page 9 for the location of these components.

3Remove the top cover (two small screws) from the contactor.

4Check for and remove any debris from the area surrounding the switch contacts. IE: ants will occasionally infest the switch contacts and eventually cause the contactor to malfunction.

5Physically test the mechanical spring action of the contactor by depressing the contactor mechanism. If the action is not smooth and/or sticks - replace the contactor.

6Perform a close visual inspection of the switch contacts. The contacts are silver plated and should be smooth. Contactor chatter (see pages 6 & 34), voltage spikes, arcing, excessive current along with normal wear and tear can cause the normally smooth surface of the contacts to become burnt, pitted and damaged. In extreme cases the contacts can “weld” closed. The switch contacts are not replaceable. If the contacts show signs of excessive wear - replace the contactor.

7Replace the top cover on all contactors when inspection is complete.

Top View Cover Plate On

Side View Cover Plate Removed

Physically Operate Mechanical

 

 

 

 

Spring Action Of Contactor

 

 

 

 

 

 

 

 

Press Down Here

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Perform Close Visual Inspection

Of Switch Contacts

Servicing should only be performed by a Qualified Service Agent

31

Image 33
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