ICP G9MVE0401410A2 Service And Technical Support Manual

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ICP G9MVE0401410A2 Service And Technical Support Manual Manual pdf 14 page image

SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MVESpecifications subject to change without notice.14 440 04 4801 00Adjust Thermostat Heat Anticipatora. Mechanical thermostat. Set thermostat heatanticipator to match the amp. draw of the electricalcomponents in the R−W/W1 circuit. Accurate amp.draw readings can be obtained at the wires normallyconnected to thermostat subbase terminals, R and W.The thermostat anticipator should NOT be in thecircuit while measuring current.(1.) Set SW1−2 switch on furnace control board toON.(2.) Remove thermostat from subbase or from wall.(3.) Connect an amp. meter as shown in Figure 6across the R and W subbase terminals or R andW wires at wall.(4.) Record amp. draw across terminals whenfurnace is in low heat and after blower starts.(5.) Set heat anticipator on thermostat per thermostatinstructions and install on subbase or wall.(6.) Turn SW1−2 switch OFF.(7.) Install blower door.b. Electronic thermostat: Set cycle rate for 3 cycles perhr.Figure 6 Amp. Draw Check with AmmeterA96316R Y W G10 TURNSTHERMOSTAT SUBBASETERMINALS WITHTHERMOSTAT REMOVED(ANITICIPATOR, CLOCK, ETC.,MUST BE OUT OF CIRCUIT.)HOOK-AROUNDAMMETEREXAMPLE: 5.0 AMPS ON AMMETER10 TURNS AROUND JAWS = 0.5 AMPS FOR THERMOSTATANTICIPATOR SETTINGFROM UNIT 24-VCONTROL TERMINALSCheck Safety ControlsThe flame sensor, gas valve, and pressure switch were allchecked in the Start−up procedure section as part of normaloperation.1. Check Main Limit SwitchThis control shuts off combustion system and energizesair−circulating blower motor, if furnace overheats. Byusing this method to check limit control, it can beestablished that limit is functioning properly and willoperate if there is a restricted return−air supply or motorfailure. If limit control does not function during this test,cause must be determined and corrected.a. Run furnace for at least 5 minutes.b. Gradually block off return air with a piece ofcardboard or sheet metal until the limit trips.c. Unblock return air to permit normal circulation.d. Burners will re−light when furnace cools down.2. Check Pressure Switch(es)This control proves operation of the draft inducer blower.a. Turn off 115−v power to furnace.b. Disconnect inducer motor lead wires from wireharness.c. Turn on 115−v power to furnace.d. Set thermostat to “call for heat” and wait 1 minute.When pressure switch is functioning properly, hotsurface igniter should NOT glow and controldiagnostic light flashes a status code 3. If hot surfaceigniter glows when inducer motor is disconnected,shut down furnace immediately.e. Determine reason pressure switch did not functionproperly and correct condition.f. Turn off 115−v power to furnace.g. Reconnect inducer motor wires, replace door, andturn on 115−v power.h. Blower will run for 90 seconds before beginning thecall for heat again.i. Furnace should ignite normally.Checklist1. Put away tools and instruments. Clean up debris.2. Verify that switches SW1−1 and SW1−6 are OFF andother setup switches are set as desired. Verify thatswitches SW1−7 and SW1−8 for the blower OFF DELAYare set as desired per Table 4.3. Verify that blower and control doors are properlyinstalled.4. Cycle test furnace with room thermostat.5. Check operation of accessories per manufacturer’sinstructions.6. Review Home Owner’s Information with owner.7. Attach literature packet to furnace.