Market Forge Industries ST-6-TGG User manual

ST-6-TGG™and ST-12-TGG™
PRESSURELESSSTEAMCOOKER
WITHGASGENERATORS
INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
AnEmployee-OwnedCompany
35GarveyStreet • Everett, MA 02149-4422 USA
Tel: [phone] • Fax: [phone]
FaxOutsideMA:1-800-227-2659
E-Mail: [email protected]
Form No. S-4846 Rev. A 11/98 Printed in U.S.A.
WARNING
Improper Installation, adjustment, alteration,
service, or maintenance can cause property
damage, injury, or death. Read the
installation, operating, and maintenance
instructions thoroughly before installing or
servicing this equipment.
FOR YOUR SAFETY
Do not store or use gasoline or other
flammable vapors or liquids in the vicinity of
this or any other appliance.
MODEL
ST-6-TGG
ST-12-TGG
COVERING
•Installation
•Operation
•ServiceandParts
Post in a prominent location to be followed in the event the user smells gas. This information shall
be obtained by consulting the local gas supplier.

MARKET FORGE INDUSTRIES,INC.
35GARVEY STREET EVERETT,MA02149
TEL:[phone] TELEX:91-9494
FAX:[phone] OUTSIDE MA:800-227-2659
Form No. S-4846 Rev. A 11/98 iii
TABLE OF CONTENTS
PARAGRAPH PAGE PARAGRAPH PAGE
SECTION1 INTRODUCTION
1.1 Description............................................1-1
1.2 BasicFunctioning .................................1-1
1.3 Service .................................................1-1
SECTION2 INSTALLATION
2.1 Assembly .............................................2-1
2.2 Setting in Place ....................................2-1
2.3 GasConnection ....................................2-1
2.4 Electric Service Connections ................2-2
2.5 WaterConnections................................2-2
2.6 InstallationCheck-Out ..........................2-2
2.6.1 Warm-up ...............................................2-2
2.6.2 TimedSteam Mode ..............................2-2
2.6.3 ConstantSteam Mode ..........................2-2
2.6.4 Shut-DownProcedure ...........................2-3
2.7 Reversingthe Doors .............................2-3
SECTION3 OPERATION
3.1 OperatingControls andIndicators .........3-1
3.2 OperatingProcedures ...........................3-1
3.2.1 DailyFiringProcedure...........................3-1
3.2.2 Cooking ................................................3-1
3.2.3 DailyShut-DownProcedure ..................3-1
3.3 Cleaning................................................3-1
3.3.1 DailyCleaning.......................................3-1
3.3.2 ProlongedShutdownandCleaning ........3-1
3.3.3 GeneratorCleaning ...............................3-2
3.4 Drainage ...............................................3-3
3.4.1 CookingCompartment Drainage............3-3
3.4.2 Drip/SpillTroughDrainage.....................3-3
3.5 Test Kitchen Bulletin.............................3-4
SECTION4 TROUBLESHOOTING
4.1 General .................................................4-1
4.2 TroubleshootingGuide ..........................4-1
4.3 Electrical Troubleshooting
Procedures .......................................4-1
4.3.1 IncomingPower ....................................4-3
4.3.2 Electrical Inspection .............................4-4
4.3.3 60-MinuteTimer....................................4-4
4.3.4 Door Interlock Switch............................4-6
4.3.5 IndicatorLights .....................................4-6
4.3.6 CookingCompartmentThermostatic Switch
4-6
4.3.7 Buzzer ..................................................4-7
4.3.8 ColdWaterCondenserCircuit ...............4-7
4.3.9 Wiring ...................................................4-7
4.4 WaterLevel Control Board ....................4-7
4.4.1 Testing the Water Fill Relay ..................4-8
4.4.2 Testingthe Low WaterRelay ................4-8
SECTION5 MAINTENANCE
5.1 General .................................................5-1
5.2 PreventiveMaintenance .......................5-1
5.2.1 CookingCompartmentCleaning ............5-1
5.3 RepairandReplacement .......................5-1
5.3.1 Door LatchTension Adjustment ............5-1
5.3.2 Door Handle Tension Adjustment ..........5-1
5.3.3 DoorGasketReplacement ....................5-2
5.3.4 ExteriorPanelRemoval ........................5-2
5.3.5 WaterSolenoidValve Replacement ......5-2
SECTION6 ILLUSTRATED PARTS LIST
6.1General .................................................6-1
6.2OrderingInformation .............................6-1
6.3 Index of Illustrated Parts List ................6-1
Illustrated Parts List........... 6-2through6-14

Form No. S-4846 Rev. A 11/98 iv
LIST OF ILLUSTRATIONS
FIGURE PAGE
SECTION3 OPERATION
3-1 Controls andIndicators .........................3-2
SECTION4 TROUBLESHOOTING
4-1 Wiring Diagram, Model ST-6 .................4-5
4-2 SchematicDiagram,
Model ST-6.......................................4-9
SECTION6 ILLUSTRATED PARTS LIST
SeePage 6-1
LIST OF TABLES
TABLE PAGE TABLE PAGE
SECTION3 OPERATION
3-1 Controls andIndicators .........................3-2 SECTION4 TROUBLESHOOTING 4-1 GeneralTroubleshootingGuide .............4-1
4-2 Electrical Fault Isolation Guide .............4-4

MARKET FORGE INDUSTRIES,INC.
35GARVEY STREET EVERETT,MA02149
TEL:[phone] TELEX:91-9494
FAX:[phone] OUTSIDE MA:800-227-2659
Form No. S-4846 Rev. A 11/98 1-1
1. INTRODUCTION
1.1 DESCRIPTION
The ST-6-TGG and ST-12-TGG is a pressureless
steamcookerconsisting of two independentlycontrolled
compartments enclosed in a single cabinet. Each cook-
ing compartment is provided with steam by individual
gasgeneratorratedat50,000 Btu/hr.Eachcompartment
is equipped with a separate three-piece door with inner
gasket plate isolated from the exterior surface. Door
latches operate by action for positive sealing of inner
door. Steam and steam-condensing circuits are electri-
cally controlled. Operating controls are displayed on a
single front-mounted panel and include separate power
switches and timers with indicator lights for selection of
constantsteam or 60-minute-longdurationcooking.
Aseparatesteam source isnotrequired for operation
ofthe pressureless cooker. ThemodelST-6 TGGispow-
eredbytwingassteamgenerators totalling 100,000 Btu/
hr. rate. The cooker is equipped for connection to all
necessary utilities, gas, electricity, hot and cold water,
andanopen drain.
1.2 BASIC FUNCTIONING
TheModel TGGmay be operatedwithonlyone
compartment in use; or both may be used simulta-
neously. Each compartment is equipped with identical
controls, allowing selection of constant steam or
60-minutetimer operation. Thecooker becomesopera-
tional when the power switch is depressed to “ON” and
the timer is set to constant steam, or the timer is set at
the desired cooking time and the compartment door is
closed. The indicator light comes on, allowing steam to
flow into the compartment.
When steam flowing inside the compartment has
raisedthe interiortemperature to195°F, thecontacts of
a thermostatic switch automatically close, completing
the circuit to the timer motor and starting the cooking
timeperiod. At theend ofthe set interval,timer contacts
switch to shut off the cooking operation and sound a
signal buzzer. The buzzer is silenced by returning the
timerdialtotheOFF position.Intheconstantsteammode,
operationwill be continuous.
Steam emitted from the compartment along with liq-
uidcookingdrainagearedirectedthrough a drain screen
inside the compartment into a cooker drain line. Both
drain lines are connected to a common condenser box
locatedinrear. A cold watersolenoidvalveconnected to
the condenser box is automatically actuated by a ther-
mostatic switch to condense the steam to water prior to
discharginginto an externaldrain.
1.3 SERVICE
Required service, both preventive and corrective, is
explainedinSection 6.Shouldrepairsberequired,anet-
work of authorized agencies is available to assist with
prompt service. A current Directory of Authorized Ser-
vice Agencies may be obtained by contacting:
ProductServiceDepartment
MarketForge
35Garvey Street
Everett, Massachusetts 02149
Telephone[phone]
The model and serial numbers must be referenced
when corresponding with Market Forge. The data plate
containingtheserialnumberpertaining to the equipment
islocatedtowardthe front on thetop panelofthecooker.
This service and parts manual contains general information, installation operation, principles of op-
eration, troubleshooting, and maintenance information for the Market Forge ST-6 Pressureless
Steam Cookers. Also included is a parts list in which each replaceable part is identified and shown
in an accompanying exploded view.

Form No. S-4846 Rev. A 11/98 2-1
2.1 ASSEMBLY
TheModel ST-6-TGGis shipped strapped andbolted
toaskid, with cabinet feetinaseparate container. Steps
required for assembly are as follows:
1. Remove the straps and four bolts that fasten the
equipment frame to the skid.
2. Install feet in threaded mounting locations of the
cabinetframe.
3. Mountthetwobaffleson studs located on theright-
inside of the cooking compartments.
4. Mount the four pan support racks in brackets in-
sidecontrol compartments.
5. Attachthe drip troughon studs locatedonthe face
of the unit.
2.2 SETTING IN PLACE
Thelocation of installationmust beunder an exhaust
hood,whichwillremove gas combustion products,small
amounts of water vapor emitted when the cooker doors
are opened, and exhaust fumes from the air. Level the
unitin final locationby turning theadjustable feet. Using
the cabinet top as a reference, obtain level adjustment
left-to-rightandfront-to-back.
CAUTION
Keepthisapplianceareafree and clear fromcombus-
tibles.
Donotobstructthe flow ofcombustionandventilation
air.
This installation must conform with local codes, or in
the absence of local codes, with the National Fuel
Gas code, ANSI Z223.1–Latest Edition. For installa-
tion in Canada, this appliance is to be in accordance
withthe current CAN/CGB-B149(.1or .2) Installation
Codefor GasBurningAppliancesandEquipmentand/
orLocal Codes.
This appliance, when installed, must be electrically
grounded in accordance with local codes, or in the
absence of local codes, with the National Electric
code, ANSI/NFPA70–Latest Edition. For installation
in Canada, all electrical connections are to be made
in accordance with CSA C22.1 Canadian Electrical
CodePart 1 and/or LocalCodes.
The boiler and its individual shut-off valve must be
disconnectedfrom the gassupply piping systemdur-
ing any pressure testing of that system at test pres-
sure in excess of 1/2psig (3.45 k/PA).
The wiring diagram adhesive label is located on the
inside of the front panel.
Thisproduct must beinstalledinaroomwithadequate
air supply.
Minimumclearancesfrom both combustible andnon-
combustible surfaces are 2"(51 mm) from right and
left wall and 2"(152 mm) from rear wall. Suitable for
installationon combustible floors/counters.
This unit is serviceable from the front and right side.
Do not install in such a manner that a service person
cannot remove the side panels. The optimum clear-
anceon the rightside is12"(302 mm), 24"(604 mm)
on the left.
Keepthis manual for future reference.
2.3 GAS CONNECTIONS
a. The generator is factory-adjusted for a gas input of
50,000 Btu/hr.at the pressureindicated.Please read
theratingplateontopoftheunit.Ifthisplateismarked
foradifferentgas than that supplied, notify your dealer
immediately. Install an external gas supply shut-off
valvein a visibleand accessible location.If the unitis
placed at the minimum side clearances rather than
theoptimum sideclearances, the onlyacceptable lo-
cation for the gas supply shut-off valve is under the
unit in the space provided by the legs.
b. Use new iron or steel pipe complying with the latest
ANSI Standard for Wrought-Steel and Wrought-Iron
Pipe, B36, properly threaded, reamed, and free from
chips, oil, and dirt. If pipe dope is used, apply a mod-
erateamount,leavingtwoendthreadsbare.Pipedope
mustbe resistant toLPgas. Connect thegasline into
the bottom (inlet) side of the shut-off valve. The sup-
ply pressure must be at least 1"(25 mm) water col-
umnhigherthanthemanifoldorregulatorpressurefor
proper function of the regulator. If it is not, check the
supply pipe for blockage or excessive pressure drop
andmake necessarycorrections.
c. Perform a gas leak test of all newly made joints, as
well as those leading to the main gas control valve.
Usea soapsolution. DONOT USE FLAME.
2. INSTALLATION