Electrolux T5675 - Drum Motor Ewd

142
Troubleshooting
DRUMMOTOREWD
21:1HEATSINKTOOHOT
ThiserrorcodeisgeneratedbytheMCUfordrummotor.
Thereisatemperaturesensor(NTC)mountedontheMCUcoolingangenexttothepower
transistorsintheoutputstage.Ifthetemperatureofthecoolingangegetstoohigh(>90°C)the
errorcodewillbesettoprotectthetransistors.
Thecauseofhighcoolingangetemperaturecanbee.g.astiffdrumincombinationwithintensive
useandhighambienttemperature.Theremayalsobeanerrorinthemotor(stickingbearingsor
shortcircuitinwindings,whichimpairstheefciencyofthemotor).
Recommendedactions:
1.Makesurethedrumturnseasily.
2.Checkthevalueontheerrorcodecounterfortheerrorcode.
3.Checkthelast8MCUerrorcodes.
4.Starta90°Cnormalprogramwithloadoncontinuousoperationandmeasurethetemperatureof
themotorandMCU.
5.Replacethedefectivepart.
21:2MOTORTOOHOT
ThiserrorcodeisgeneratedbytheMCUforthedrummotor.
Eachtimethemotorisstartedfromstationary,theMCUwillrstmeasuretheresistancebetween
twophasesinthemotor.TheMCUprocessorgovernstheoutputtransistorssothataDCcurrent
owsbetweentwophasesinthemotorwinding.Theactuationofthetransistorsisameasureofthe
voltageappliedtothewindingandtheresistancecanbecalculatedusingthecurrentandvoltage
values.Theresistancecanthenbeconvertedtoatemperaturesincethewindingresistanceat
20°Candthetemperaturecoefcientareknown.Iftheaveragevalueofthefourlatesttemperature
readingsishigherthanthemaximummotortemperature(e.g.150°C),theerrorcodewillbeshown.
Possiblecauses:
Thecauseofhighmotortemperaturecanbeastiffdrum,possiblyincombinationwithintensiveuse
andhighambienttemperature.Theremayalsobeanerrorinthemotor(stickingbearingsorshort
circuitinwindings,whichimpairstheefciencyofthemotor).Therecouldalsobeacontacterrorin
theconnectorsbetweentheMCUandthemotororanerrorinthemotorcable.AnerrorinMCU
temperaturemeasurementcircuitscanalsooccur.
Recommendedactions:
•Makesurethedrumturnseasily.
•Checkthevalueontheerrorcodecounterfortheerrorcode.
•Checkthelast8MCUerrorcodes.
•MeasurethethreephasestothephaseresistorsontheMCUmotorconnector(disconnectMCU
andtakethereadinginthecableconnector)tomakesuretheyarethesame.
•Starta90°Cnormalprogramwithloadoncontinuousoperationandmeasurethetemperatureof
themotorandMCU.
•Replacethedefectivepart.