A.O. Smith SGE service manual Appliances heating cycle, Working principle of the appliance

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	2		Working principle of the appliance

Cut-away view of the appliance

Legend

Only applicable numbers are mentioned.

1. cover

2. hot water outlet

3. electrical connector block

4. electronic controller

5. pressure switch

6. control panel

7.temperature sensor T1

8.combustion chamber

9. anode

10. tank

11. heat exchanger

12. inspection and cleaning opening

13. temperature sensor T2

14.cold water inlet

15.drain valve

16. gas control

17. burner

18. fan

19. air supply hose

20.hot surface igniter

21.flame probe

22. chimney pipe

23. siphon

24. insulation layer

29. pallet

55. heat exchanger (e.g. solar heating system)

56. temperature sensor S2

gis

2.3The appliance's heating cycle

The net water temperature (Tnet) in the appliance is used to regulate when both the gas burner and the solar heating system are started and stopped. Tnet is the curve shown in the figure. The controller uses two measured values to calculate this temperature: T1 (7) and T2 (13). In addition, temperatures S1 and S2 are used by the solar heating system controller. S1 is measured in the solar collector and S2 between the inlet and outlet of the heat exchanger (55).

The other settings that govern the control behaviour are:

•Tset

Tset is the the required water temperature that has been set on the appliance (11.4.1 "Setting the water temperature via the SET POINT MENU"). As soon as Tnet falls below Tset, the water heating via the solar heating system is started, however, only if the temperature of the heating fluid (S1) is a certain (adjustable) value higher than the temperature measured at the appliance (sensor S2). As soon as (Tnet = Tset = Tsolar limit), heating via the solar heating system is stopped. There is one exception to this rule, and that is when Tsolar limit is set to a higher value than Tset.

14	Instruction manual SGE

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Contents Installation User Your installer Liability Read this manual carefullyTrademarks More informationGis Table of contents Maintenance frequency Service programTroubleshooting Status of the applianceAppendices Performing maintenanceWarranty certificate Table of contents What to do if you smell gas Regulations IntroductionAbout the appliance Introduction Target groups Maintenance Forms of notationSymbol Target group Overview of this document Chapter Target groups DescriptionGis Topics covered in this chapter Working principle of the applianceIntroduction General working principle of the appliance Working principle of the appliance Other settings that govern the control behaviour areAppliances heating cycle Pressure switch Flame probe = time = Temperature 45 oC = Minimum tap water temperatureAppliance water temperature protection Gas valve Protection for the appliance IntroductionGas valve Appliance water temperature protectionPressure switch 4 FanVented installation Safety of the installationUnvented installation Flame probeExpansion valve Fluid temperatureSafety of the solar heating system Expansion vessel Pump of the solar heating systemEnvironmental InstallationPackaging ConditionsWater composition Air humidity and ambient temperatureAppliance maximum floor load Working clearances Appliance is supplied without accessories. Check Technical specificationsDimensions of the appliance See the tableDime Description SGE Nsion General and electrical specifications Gas dataGas category 3+ G31 37 mbar Installation diagram Hot water side See C in the installation diagram 3.5 Installation diagramWater connections, Unvented Cold water side Circulation pipeWater connections, Vented Condensation drainageRequirements for flue gas discharge materials Gas connectionAir supply and flue Introduction This section covers the following subjectsTypes of appliances Concentric connections Practical example of concentric chimney flue SpecificationsFollowing example illustrates how to use the table Appliance Diameter Maximum Parallel connectionsSubject Description Total length BendPractical example of parallel chimney flue Appliance with parallel flue gas discharge materialSolar heating system Preparation Connecting the mains voltageConnecting communication cable to solar heating system Electrical connection11.2 PreparationIsolating transformer Connecting the mains voltageConnecting continuous pump 11.2 PreparationConnecting an extra error signal Alarm OUT Connecting a program-controlled pumpConnecting an extra on mode switch Tank on Connecting extra head pump Connecting Q/T sensorConnecting solar collector Connecting the mains powerConnecting pump station modulating pump Connecting extra head pump Connecting tank sensorConnecting communication cable Connecting Q/T sensorChecking the supply pressure and burner pressure Procedure to check pressures Finish off 3.13.4 Finalising Adjusting the pressureGas data 13.4 FinalisingOrifice assembly Conversion to a different gas categoryBurner pressure regulator Blank plate Gas control connector Conversion to a different gas categoryPage Conversion to a different gas category Filling Filling Filling the appliance Filling unvented installationsFilling vented installations Flushing with water Filling with glycolGis Draining Activate the Menu with Draining unvented InstallationsDraining Position the cursor in front of OFFPosition the cursor in front of OFF Confirm OFF with Draining vented installationsDraining solar heating system Draining glycol-filled system Gis Controls Electronic controller ON/OFF switchControl panel Meaning of iconsControl panel Navigation buttonsPC connection Operating modes Operating modes Error conditions Service conditionStatus of the appliance Collector temperature warning Service conditionError conditions Q/T Sensor warningStarting the appliance Open 3.5 Installation diagram the manual gas valveStarting and running Starting the appliance Appliances heating cycleIcon is activated Message Ignition appears Starting and runningIcon is activated Message PRE Purge appears Shutting the appliance down for a long period Shut the appliance down for a brief period OFF modeShutting down Electrically isolating the applianceShutting down Main menu Switching on the on modeSet the water temperature via Notational convention for menu-related instructionsStarting and stopping the week program Setting water temperature during on modeWeek program Changing the appliances standard week programWeek program setting the water temperature Week program setting the switch- on timeWeek program setting the switch- off time Bring the cursor to SU Confirm withConfirm with Display shown in the figure will appear Week program setting the program- controlled pumpAdding times to a week program Scroll with to Start Operation Confirm withExtra period Confirm with Or use to cancelDeleting times from a week program To delete a period, proceed as followsSetting the water temperature Setting the switch-on timeSetting the switch-off time Setting the program-controlled pumpSetting day and time SettingsSetting menu language Adjustable settingsTable shows the correct settings Displaying appliance specifications SGEConfirm the minute setting with Scroll with to Specifications Confirm withDisplaying the error history Service programSetting the hysteresis Appliance Default RangeSetting legionella prevention Switching the pump on or offSetting the service interval Switching legionella prevention on and offSetting the heating fluid type in the solar heating system Solar heating system configurationSetting the drain-back tank Setting the solar limit temperatureReading the energy contribution of the solar heating system Setting the QT sensor yes/noSetting the central heating configuration Displayed errors TroubleshootingGeneral errors Distinction is made betweenDisplay is off Troubleshooting table for general errorsSymptom Cause Solution Remark Gas smell Start the appliance up 9 Starting and runningHot water supply Symptom Cause Solution Remark Water leakageExplosive ignition Insufficient or absentSymptom Cause Solution Remark Troubleshooting table for displayed errors Displayed errors S12 blocking error Code + Description Cause Solution RemarkS11 blocking error S13 blocking errorF02 lock out error Code + Description Cause Solution Remark S18 blocking errorF01 blocking error Maintenance 15.2 Preparation for maintenance. If there is Code + Description Cause Solution Remark F03 lock out errorFails to work correctly Engineer Pressure switch not ClosingNo gas Code + Description Cause Solution Remark F04 lock out errorF05 lock out error AreaF08 lock out error Code + Description Cause Solution Remark F06 lock out errorF07 lock out error Safety relay EngineerCode + Description Cause Solution Remark F10 lock out error F11 blocking errorC04 blocking error Code + Description Cause Solution Remark C02 lock out errorC03 blocking error Selected applianceE03 lock-out error Code + Description Cause Solution Remark E01 blocking errorTemperature E04 lock-out errorDisplayed warnings Maintenance, based on the number of burning hours Maintenance frequencyBest maintenance frequency can be determined Standard setting is 500 burning hoursMaintenance frequency Wait until the fan has stopped. The icon is then dimmed Performing maintenanceIntroduction Preparation for maintenance Performing maintenance Checking the anodes Water-side maintenance IntroductionDescaling and cleaning the tank Following steps must be carried out on the water sideClean the burners Cleaning condensation water dischargeGas-side maintenance Introduction Clean the orifices16.2 Tank warranty Warranty certificate16.1 General warranty Collector warranty Conditions for Installation and useWarranty certificate Menu structure of the main menu 17.2 Menu structure AppendicesThis appendix contains Heating systemMenu structure Appendices101 Electrical diagram for the appliance Electrical diagramController 0/I switch Extra on mode switchExtra error signal connection Temperature sensor T1 topElectrical diagram, solar heating system Solar system electrical diagram legend 106 Tset Pump Week program cardPeriod Example Period108 Index 1090308 Index