Norcold N611V SERIES Service Manual

Also see for N611V SERIES: Owner's manual

Norcold N611V SERIES Service Manual Manual pdf 9 page image

www.norcold.com/cda 9N611v, N811v ModelsRefrigerator Service ManualElectronic ControlsA precise heat is applied to the boiler area of the coolingunit causing a chemical reaction within the cooling unit thatultimately results in the refrigerator cooling. The heat applied isdone so by means of:• AC cartridge type heater positioned in heater wellswelded to the surface of the boiler• LP Gas burner positioned below the boiler suchthat the heat from the flame is directed across thesurface of the boilerThese heat sources are turned on/off via a factory presetAuto mode. The unit will attempt to operate the heat sourcerequirements in the following order of priority:• 1st Priority Choice - Auto AC ModeWhile in the Auto AC Mode, the AC cartridge heateris operated to provide heat to the boiler area of thecooling unit.• 2nd Priority Choice - LP Gas ModeWhile in the Auto LP Gas Mode, the LP gas burneris operated to provide heat to the boiler area of thecooling unit.A thermistor is mounted on the fin assembly located inside thefresh food compartment. The thermistor acts as a temperaturesensor, reporting the temperature sensed to the opticaldisplay. The optical display then relays this information tothe power board that then turns on/off the appropriate heatsource accordingly. The optical display board, power board,thermistor, and other components within the refrigerator areinterconnected via a wire harness.Theory of Operation -Auto ModesAC voltage is applied to the power board via the AC powercord at terminals L1 (Hot) and L2 (Neutral). This AC voltagewill pass through the AGC Series, 8A, Fast Acting, Glass TubeFuse (F2) where it is then measured. This measurement iscommunicated to the optical display board which determines ifthe applied voltage is below or above 85VAC. If the voltage isabove 85VAC the determination is that AC voltage is availableand the optical display board will request the power board tooperate via the Auto AC Mode. If the voltage is below 85VACthe determination is that AC voltage is NOT available and theoptical display board will automatically default to the Auto LPGas Mode and request the power board to operate via theAuto LP Gas Mode (see below). If the control is not able toestablish a fl ame while operating in the Auto LP Gas Mode theoptical display board will:Automatically default back to the Auto AC mode and wait forAC voltage to return, displaying the following fault code• Solid RED power indicator lightAuto AC ModeWhen operating in the Auto AC mode the power boardmeasures the thermistor value and communicates it to theoptical display board. The thermistor, a temperature devicewhose internal resistance goes down as the temperature goesup, is connected to the power board via terminals P2-1 andP2-6. The optical display board compares the actual thermistorvalue to preset cut-in and cut-out temperature values. Shouldthe thermistor value fall below the cut-in value it will requestthe power board to turn ON the AC heater relay (K2). Shouldthe thermistor value go above the cut-out value it will requestthe power board to turn OFF the AC heater relay.Anytime relay K2 is turned ON, AC voltage is applied tothe AC heater via the now closed K2 contacts. Anytime ACvoltage is applied to the AC heater, AC current is produced.This AC current is measured by the power board and itsvalue communicated to the optical display board. The opticaldisplay board determines if the AC current is within specifiedlimitations. If below the minimum specifi ed limit, the opticaldisplay board will automatically default to the Auto LP GasMode and request the power board to operate via the AutoLP Gas Mode. AC related faults (Voltage or Current) are notdisplayed while operating in the Auto Mode of operation.