Global 5120 - System Components

GlobalPowerTechnologies  3-3
5120
3.2 System Components
Themainpartsofthe5120TEGareasfollows(seeFigure14):
Power Unit: The power unit includes the thermopile and the cooling ns.  The thermopile
consistsoftheNandPelements(thermocouples)placedinasealedcompartmenttoprevent
oxidationandsurroundedbyinsulationtopreventheatloss.
Cooling Fins:Coolingofthethermopileisdonebythefreemovementofambientairthrough
thecoolingns.Checkthatthecoolingnsareclearofleavesandotherdebris.Thereshould
beenoughspacearoundthensforairmovement.
Burner:Gasisexpandedthroughanoriceandthenowsthroughaventuriwhereitdraws
inairneededforcombustion.Thismixturepassesthroughtheburnerscreenandburnsatthe
backofthecombustionchamber(nexttothethermopile).
Fuel System: Thepoweroutputofthegeneratoriscontrolledbyadjustingtheamountoffuel
senttotheburner.Thefuelsystemcontainsapressureregulatorwhichallowsadjustmentof
fuelow,apressuregauge,andapressureswitchwhichsignalsthesparkignitionsystemthat
fuelispresent.AnoptionalShut-O󰀨(SO)valvemayalsobepresentwhichcloseswhenheat
isnolongerpresentintheexhauststack,therebystoppingtheowofgas.
Spark Ignition (SI) Module: Whenthefuelisturnedon,thegaspressurecausesthepressure
switch(locatedonfuelsystem)toclose.ThissignalstheSImoduletogenerate12kVsparks,
which arc from the SI electrode to the combustion chamber wall, causing ignition to occur.
OncethefuelisburningtheexhaustheatwillsignaltheSImoduletostopsparking.
Limiter Converter (L/C):The220WattL/Cconsistsoftwoseparatecircuits.Therstisa
shunttypevoltagelimiterthatregulatestheoutputofthegenerator.ThesecondisaDCtoDC
converterthatswitchestheinputvoltagetoadi󰀨erentoutputvoltage.
Protective Limiter:WhentheTEGdoesnothaveaLimiterConverteritwillhaveaProtective
Limiterlocatedontheundersideofthecabinet.Itisashunttypevoltagelimiterthatregulates
theoutputofthegenerator
Cabinet: Thepowerunit,burnerandfuelsystemareenclosedinthestainlesssteelcabinet.
Fin Duct: Thenductactsasachimney,causingambientairtorisethroughthecoolingns,
thuscoolingthethermopile.
3.2.1 Power Unit
The power unit contains the thermoelectric materials which produce the electrical power.
Becausethesematerialscorrodeinatmosphericconditionsathightemperaturestheyarecon-
tainedinasealedunit.
IfallotherpartsoftheTEGhavebeencheckedoutanditstilldoesnotproduceratedpower
thenthepowerunitmaybefaulty.Checkthemomentaryopencircuitvoltageasfollows: