Camus Hydronics DFH500 Installation, Operation And Service Manual

Also see for DFH1100: Installation, operation and service manual

Contents

Camus Hydronics DFH500 Installation, Operation And Service Manual Manual pdf 29 page image

26The ignition module relies on the flame sensor to provide aflame rectification signal. Oxide deposits, improperplacement or damaged ceramic insulator will result ininsufficient signal leading to ignition module lock out. Forproper operation minimum 2.0 μA DC must be fed back tothe module. Oxide deposit on the sensor rod must beremoved with steel-wool. Do not use sand-paper since thiswill contaminate the surface.7.3 COMBUSTION AIR FANFigure 20 – Fan, Burner, Hot Surface Igniter and FlameSensor ArrangementDynaFlame uses a sealed air fan to provide combustibleair/gas mix to the burner and push the products ofcombustion through the heat exchanger and ventingsystem. The fan assembly consists of a sealed housing andfan wheel constructed from spark resistant cast aluminum.The fan is operated by a fully enclosed 230 VAC, 3 Phaseelectric motor. The fan housing and motor assembly is fullysealed and SHOULD NOT be field serviced. The powerdraw of the motor is proportional to the modulated gas inputrate of the appliance.7.4 INNER JACKETThe inner jacket assembly is constructed from a specialcorrosion resistant stainless steel. This includes both theprimary heat exchanger chamber and the secondary heatexchanger chamber. All screws and fasteners used forassembly of the inner jacket and secondary heat exchangerchamber are also stainless steel.DO NOT mix stainless steel and standard platedfasteners when disassembling and reassembling theinner jacket sheet metal components. Standard platedfasteners will be damaged by the flue productcondensate when used on the inner jacket assemblies.7.5 OUTER JACKETThe outer jacket assembly is constructed from mirror finishstainless Steel. This ensures a long life for the jacketassembly, with full integrity7.6 VENTING TRANSITIONAll appliances are shipped with a rectangular to roundstainless steel adapter. Depending on the appliancecategory an increaser will be required for the proper ventconfiguration. Please refer to table #3 dimensions andspecifications.When installing Category II or IV appliances care must betaken to properly seal all joints and provide slope fordrainage of condensate.PART 8 FIELD STARTUPPROCEDURE8.1 CHECKING THE INSTALLATION• Inspect the connections for water, gas and electricity.• Confirm that water is being pumped toward the heatexchanger inlet. Never pump away from the exchangersince this will result in a low-pressure zone, which willallow localized boiling and result in heat exchangerdamage.• Power to the boiler and pump must be from the samecircuit to prevent the boiler firing in case the pump isinadvertently shut off.• Inlet gas pressure must be a minimum of 3” W.C. fornatural gas and 11” W.C. for propane.• With the boiler off, open the main gas supply valve andvent the trapped air from the piping leading to theboiler. Confirm that all gas connections to the heaterare tight and that there are no missing test plugs.• Connect a manometer to obtain the differential airpressure between negative and positive ports. SeeFigure #3.• The air/gas ratio controller automatically adjusts tomatch the air signal on the gas side. In this way truemass flow control of air/gas mix is achieved. Typicaldifferential air settings are listed in Table 8. All boilersare test fired and factory set. A test sticker with actualreading is affixed to the unit. In general, these readingswill be within 0.3” W.C. of the readings shown inTable 8.Refer to Part 3 of the manual for recommendations onsetting combustion characteristics.8.2 CHECKING THE CONSTRUCTION• Check the boiler wiring to see that it agrees with thewiring diagram supplied.• Confirm that all terminal strips and field connectionsare identified.• Confirm that the SmartFlame control is set in theproper mode. In remote mode an external controllerdetermines the set point and the stage contacts on theSmartFlame are always closed. Auto reset limits arefixed in all Modes.• With the firing valve in the off position, switch on powerto the boiler. The indicator lights will sequentiallyenergize to show that the operator, limit control andwater flow are functioning properly. The fan motor willaccelerate until the airflow light energizes. If a lightremains off, the ignition sequence will not proceed.During trial for ignition the red flame failure light maylight up momentary.• Once all lights are energized the ignition module will tryfor ignition. When the igniter is hot enough, the ratiogas valve actuator is energized and if ignition isaccomplished the blue main burner light will come onand remain lit. If ignition is not accomplished, the redflame failure light will energize and two more ignitiontrials will be made 15 seconds apart. The control willthen proceed to lockout and must be reset bymomentarily interrupting power. It is normal during