Owner's manual

Model 702G/O Advanced gas/oil burners — Instruction manual
Carlin part number MN702GO Rev. 06/23/14
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Where appliance instructions differ from this manual, follow the appliance instructions.
702G/O overview
TheModel702G/Ocombinationgas/oilburnerisalow-high-low(step
modulating)burnerthatutilizesadampermotortocontrolair(andgasfuel
rate).FuelisselectedusingtheGas/oilchangeoverswitch.Theburner
operatesoneither#2fueloilorgas(naturalorpropane).
Seethenextpageforgastraincomponentlocations.
Gas mode operation
Ignitionformainameisaccomplishedbyaprovedgaspilotofapproxi-
mately280,000Btuh.Pilotgasisintroducedatthemainburnerame
retention ring, and is ignited by a Carlin 14,000-volt electronic ignitor
wiredtothetwoelectrodes.Afterthepilotameisproven,thetwomain
gassafetyvalvesopen.Thepilotgasvalveclosesafteratimedelayto
allowmainametoestablish.Flameismonitoredbothforpilotameand
mainamewithaUVscannermountedtotheundersideoftheburner
combustionheadassembly.Theburnermainamebeginsatlowre.
Ifadditionalinputisrequired,thedampermotoropensthegasbuttery
valveandairdampertotheirhighrepositions.
Gasisintroducedintotheburnerthroughamanifoldaroundtheairtube.
Thegasthencirculatesthroughasetoffouroricespudsintotheair
stream,aheadoftheretentionring.Thespinoftheairowattheretention
ringthoroughlymixesthegas/airbeforeitreachesthecombustionzone.
Oil mode operation
OilignitionisaccomplishedbytheCarlin14,000-voltelectronicignitor
wiredtothetwoelectrodes.Theoilamebeginsatlowre,with100psig
oilpressureatthenozzle.Ifadditionalinputisneeded,thedampermo-
toropenstheairtothehighreposition.Thedampermotorendswitch
energizesthe2ndstageoilvalve(fuelunitblockingvalve)asthedamper
approachesitshighreposition.Thisprovides300psigpressuretothe
oilnozzleforhighre.FlameismonitoredbytheUVscannermounted
totheundersideofthecombustionheadassembly.
Firing rate adjustment
• Firingrateisdeterminedbytheoilnozzle.Airowismatchedtotheoil
owforoilring.Thengasowisadjustedtomatchtheairowatlow
andhighrerates.
• Seethe“Startingandoperating”sectionofthismanualforthecomplete
descriptionoftheadjustmentprocess.Thefollowingisabriefsummary
only.
• High-reairissetbyadjustingthecombustionheadposition(tocontrol
airowthroughandaroundtheretentionring).
• Low-reairisthenadjustedbyne-tuningthepositionofthelowre
adjustingscrew.
• Pilotgasowissetforasmoothlight-off.Thengasinputsareadjusted
forgoodcombustionatlowandhigh-reairsettings.
1. The Carlin Model 702G/O combination gas/oil burner
702G/O oil nozzles
 Usethe selections below when the heating equipment
manufacturer’sspecicnozzleselectiondataisnotavailable,
eitherintheequipmentmanualortheCarlinOEMSpec
Guide.Followallinstructionsprovidedwiththeappliance.
Nozzle specifications
• Preferred— Hago45°SS
• Alternate— Hago45°PorMonarch45°PLP
Nozzle ratings
Fullinput(highre)occursat300psignozzlepressure.Sincenozzles
areratedat100psig,theactualowat300psigisapproximately73%
higherthan therated nozzlecapacity.See thetable belowfornozzle
ratingselections.
Table 1 702G/O oil nozzles
Oil Nozzle Sizing
Equipment
Input rating
GPH
Recommended
nozzle rating
GPH
Low fire
input
(100 psig)
High fire
input
(300 psig)
6.00 3.50 3.50 6.00
6.50 3.75 3.75 6.50
6.90 4.00 4.00 6.90
7.80 4.50 4.50 7.80
8.70 5.00 5.00 8.70
9.50 5.50 5.50 9.50
10.40 6.00 6.00 10.40
11.20 6.50 6.50 11.20
1. For a packaged appliance application on which the burner has been tested, use the noz-
zle given in the appliance manufacturer's instructions or supplement for the best
results.
Gas pressure requirements
The702G/Oburnerrequires3.4"w.c.minimumpressureatthebuttery
valveduringhighre.Selectagastrainthathasapressuredropno
morethantheavailablepressureatthegastraininletminusthe3.4"
neededatthebutteryvalve.Seepage13forgastrainpressuredrop
information.Theburnerisequippedwitha1"gastrainunlessalarger
gastrainisordered.
Example:Aboilerhasaninputratingof1,300,000Btuh.Gaspressure
availableatthe gas trainentranceis 6.0" w.c.Subtract3.4” from the
available6.0"w.c.Thegastrainpressuredropmustbe2.6”orless.A1"
gastrainhasapressuredropof3.3"w.c.,andcannotbeused.Selecta
1¼"RV-61regulatorgastrain,whichhasapressuredropof0.87"w.c.