Toro Groundmaster Series - Transient Voltage Suppression (TVS) Diode

TransientVoltageSuppression(TVS)Diode
g305819
Figure101
1.TVSdiode
Atransientvoltagesuppression(TVS)diodeassemblyisusedtoprotectthe
electricalsystemcomponentsfrompowersurgescreatedbyenergizingand
de-energizingthePTOclutchcoil.TheTVSdiodeplugsintothemainwire
harnessabovetherightrearcorneroftheoperator’splatform.TheTVSdiode
canbeidentiedbyitsyellowcolorandTVSdiodesymbolontheendofthe
diodebody.
IftheTVSdiodefails,itmaycauseashortinthecircuit.Thistypeoffailurewould
causefuseFB1–F4toblow.TesttheTVSdiodeiffuseFB1–F4blowsrepeatedly.
IftheTVSdiodefails,itmaycauseanopencircuit.Thistypeoffailurecould
damagetheTDMcontrolleroutputforthePTOclutch.TesttheTVSdiodeifthe
PTOclutchcoildoesnotenergizeorde-energizecorrectly.
TestingtheTransientVoltageSuppression(TVS)Diode
1.Parkthemachineonalevelsurface,lowerthecuttingunit(orattachment),
engagetheparkingbrake,setthekeyswitchtotheOFFpositionandremove
thekeyfromthekeyswitch.
2.LocateandremovetheTVSdiodefromthewireharness.Checkthediode
andthediodeholderfordamageorcorrosionandcleanorrepairifnecessary.
3.Usethetableprovidedandamultimeter(ohmssetting)tomeasurethe
resistanceacrossthediodeterminals.
Multimeter
Red(+)Lead
Multimeter
Black(-)Lead
Desired
Resistance
DIODE
TERMINALA
DIODE
TERMINALB
VERYLOW
DIODE
TERMINALB
DIODE
TERMINALA
VERYLOW
4.IftestingdeterminestheTVSdiodeisfaulty,replacethediode.
5.IftheTVSdiodetestscorrectlyandacircuitproblemstillexists,checkthe
wireharnesses;refertoAppendixA(pageA–1).
6.Aftertestingiscomplete,makesuretheTVSdiodeisfullyinstalledintothe
connectorandsecuredtothewireharness.
ElectricalSystem:TestingtheElectricalComponents
Page6–52
Groundsmaster
®
3200,3300and3310
19240SLRevA