Raypak 090A Installation And Operating Instructions Manual

Contents

4. SERVICING PROCEDURESGENERAL LOCATION OF CONTROLSCONTROL BOX COMPONENT LOCATIONSIgnition Module(Auto Ignition Only)13SEQUENCE OF OPERATIONINTERMITTENT IGNITION DEVICE (IID)Heaters equipped with the IID system will automati-cally light the pilot burner first and then the main burner,each time there is a call for heat from the tankstat.Whenever the tankstat is calling for heat, the circulatorsupplied with the heater, will be energized and shouldbe running. The ignition control module will also beenergized to initiate the pilot ignition by opening the firstmain valve (pilot). At the same time, the electronicspark generator in the module produces a high voltagespark pulse output that lights the pilot burner. If the pilotburner does not light, the module will not energize thesecond main valve and the burners will not light.Ignition spark continues only until the timed trial forignition period ends. Then, the module goes into safetyshutdown or lockout. Lockout de-energizes the firstmain valve operator and closes the first main (pilot)valve in the gas control, stopping pilot gas flow. Theignition control system must be reset by setting thetankstat below water temperature for one minute or byturning off power to the module for one minute. Whenthe pilot flame is established, flame rectification circuitis completed between the sensor and burner ground.The flame sensing circuit in the module detects theflame current, shuts off the spark generator and ener-gizes the second main valve operator which opens thesecond main valve. This allows gas to flow to theburners where it is ignited by the pilot burner flame.When the tankstat is satisfied, the valve operators arede-energized shutting off the pilot and main burners,and also the circulator.Fig.# 8195.3CirculatorManual Reset LimitPressureRelief ValveField WiringCompartmentTemperature SensorIgnition Module(Auto Ignition Only)TransformerRoll-Out SensorGas Valve