Market Forge Industries ST-24 User manual

0
OWNER’S MANUAL
ST-24 PRESSURELESS STEAM COOKER
Model: □ST-24
INSTALLATION, OPERATION, MAINTANANCE, PARTS AND SERVICE
WARNING:
IMPROPER INSTALLATION, ADJUSTMENT,
ALTERATION, SERVICE OR MAINTENANCE CAN
CAUSE PROPERTY DAMAGE, INJURY OR DEATH.
READ THESE INSTALLATION, OPERATION 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.
Form Number: S-4627 Rev. B 10/12
Printed in USA 35 Garvey Street, Everett, MA 02149
Telephone [phone], Fax [phone]
[email protected]m, www.mfii.com
CAUTION:
INSTRICTIONS TO BE FOLLOWED IN THE EVENT
THE USER SMELLS GAS SHALL BE POSTED IN A
PROMINENT LOCATION. THIS INFORMATION
SHALL BE OBTAINED BY CONSULTING THE LOCAL
GAS SUPPLIER.

1
Table of Contents
INTRODUCTION ..................................................................1
Description:....................................................................1
Basic Functioning: ..........................................................1
Shipping Damage Claim Procedure:...............................1
Visible loss or damage:.............................................1
File claim for damages immediately:........................1
Concealed loss or damage:.......................................2
Service:...........................................................................2
INSTALLATION ....................................................................3
ASSEMBLY ......................................................................3
SETTING IN PLACE ..........................................................3
MECHANICAL CONNECTIONS.........................................3
WATER CONNECTIONS...................................................3
INSTALLATION CHECK-OUT ............................................3
Initial Control Settings..............................................4
Cooker Check-Out ....................................................4
Shut-Down Procedure ..............................................4
REVERSING THE DOORS .................................................4
OPERATION ........................................................................7
OPERATING CONTROLS AND INDICATORS .....................7
OPERATING PROCEDURES..............................................7
Steam Source Operation ..........................................7
Preheating ................................................................7
Cooking.....................................................................7
Shut-Down Procedure ..............................................8
Cleaning .........................................................................8
DRAINAGE ......................................................................8
Cooking Compartment Drainage..............................8
Drip/Spill Trough Drainage .......................................8
CONTROLS AND INDICATORS.........................................9
TEST KITCHEN BULLETIN ..............................................10
Facts on Parade ......................................................10
COOKING GUIDE ..........................................................11
PRINCIPLES OF OPERATION .............................................14
GENERAL ......................................................................14
PLUMBING CIRCUITS....................................................14
Steam Inlet Line......................................................14
Steam Exhaust and Drain Lines ..............................14
Steam Exhaust Condensing System........................14
ELECTRICAL CIRCUITS...................................................15
Control Circuit Components...................................15
60 Minute Timer/Constant Steam..........................15
Indicator Lights.......................................................16
Buzzer.....................................................................16
Door Interlock Switch.............................................16
Thermostatic Switch...............................................16
Digital Timers (Optional)........................................ 16
Kettle Switch (Optional)......................................... 16
TROUBLE-SHOOTING ....................................................... 17
GENERAL...................................................................... 17
Trouble-Shooting Guide .............................................. 17
Electrical Fault Isolation......................................... 17
Electrical Trouble-Shooting Procedures................. 17
GENERAL TROUBLE-SHOOTING GUIDE TABLE............. 17
Incoming Power..................................................... 18
Electrical Inspection............................................... 18
ELECTRICAL FAULT ISOLATION GUIDE ......................... 19
60-MINUTE TIMER....................................................... 19
Timer Contacts....................................................... 19
Timer Motor .......................................................... 19
Door Interlock Switch ............................................ 20
Steam Solenoid Valves........................................... 20
Indicator Lights ...................................................... 20
Cooking Compartment Thermostatic Switch ......... 20
Buzzer .................................................................... 21
Cold Water Condenser Circuit ............................... 21
Wiring .................................................................... 21
Wiring Diagrams .................................................... 22
MAINTENANCE ................................................................ 25
GENERAL...................................................................... 25
PREVENTIVE MAINTENANCE ....................................... 25
Cooking Compartment Cleaning............................ 25
Cleaning Procedure................................................ 26
REPAIR AND REPLACEMENT ........................................ 26
DOOR LATCH TENSION ADJUSTMENT.................... 26
Door Handle Tension Adjustment.......................... 26
Door Gasket Replacement ..................................... 26
Exterior Panel Removal.......................................... 27
Steam and Water Solenoid Valve Replacement .... 27
ILLUSTRATED PARTS LIST................................................. 28
Cabinet Assembly .................................................. 28
Cabinet Assembly Parts List ................................... 29
Door Latch and Handle .......................................... 30
Door Latch and Handle Parts List........................... 30
Door Assembly....................................................... 31
Door Assembly Parts List ....................................... 31
Control Panel Assembly ......................................... 32
Control Panel Assembly Parts List.......................... 32
Condenser Assembly ............................................. 33
Condenser Assembly Parts List .............................. 33

1
INTRODUCTION
This service and parts manual contains general information, installation operation, principles of
operation, trouble-shooting, and maintenance information for Market Forge ST-20 Pressureless Steam
Cookers. Also included is a part list in which each replaceable part is identified and shown in an
accompanying exploded view.
Description:
The ST-24 is a pressureless steam cooker consisting of two independently controlled compartments
enclosed in a single cabinet. Each compartment 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 electrically controlled. Operating controls are
displayed on a single front-mounted panel and include separate timers with indicator lights for selection
of constant steam or 60-minute-long duration cooking.
A separate steam source is required for operation of the Pressureless Cooker and is normally purchased
with it; please refer to the respective manual for guidance.
Basic Functioning:
The Model ST-24 may be operated with only one compartment in use; or both may be used
simultaneously. Each compartment is equipped with identical controls, allowing selection of constant
steam or 60-minute timer operation. The cooker becomes operational when it 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 and the steam solenoid valve opens, allowing steam to flow into the compartment.
When steam flowing inside the compartment has raised the interior temperature to 195°F, the contacts
of a thermostatic switch automatically close, completing the circuit to the timer motor and starting the
selected cooking time period. At the end of the set interval, timer contacts switch to shut off the cooking
operation and sound a signal buzzer. The buzzer is silenced by returning the timer dial to the OFF
position. In the constant steam mode, operation will be continuous.
Steam emitted from the compartment along with liquid cooking drainage is directed through a drain
screen inside the compartment into the cooker drain line. A cold water solenoid valve connected into
the cooker drain line is automatically actuated by a thermostatic switch in the cooking compartment
drain to condense the steam to water prior to discharge into the drain.
Shipping Damage Claim Procedure:
The equipment is crafted and inspected carefully by skilled personnel before leaving the factory. The
transportation company assumes full responsibility for safe delivery upon acceptance of this equipment.
If shipment arrives damaged:
Visible loss or damage:
Note the damage or loss on freight bill or express delivery and signed by the person making the delivery.
File claim for damages immediately:
Regardless of the extent of damages.

2
Concealed loss or damage:
If damage is noticed after unpacking, notify the transportation company immediately and file a
"Concealed Damage" claim with them. This should be done within fifteen (15) days from the date
delivered. Retain container for inspection.
Service:
Installation of the equipment should be performed by qualified, certified, licensed and/or authorized
personnel who are familiar with and experienced in state/local installation codes.
Operation of the equipment should be performed by qualified and authorized personnel who have read
this manual and are familiar with the functions of the equipment.
Service of the equipment should be performed by qualified personnel who are knowledgeable with
Market Forge cooking equipment.
Should repairs be required, a network of authorized agencies is available to assist with prompt service. A
current Directory of Authorized Service Agencies may be obtained by contacting:
Product Service Department
Market Forge Industries Inc.
35 Garvey Street
Everett, Massachusetts 02149
Telephone [phone]
Toll Free [phone]
Parts and Service [phone]
Email [email protected]
Website http://www.mfii.com/index.php/company/service for a listing of Authorized Service Agents.
The model and serial numbers must be referenced when corresponding with Market Forge. The data
plate containing the serial number pertaining to the equipment is located on the lower front trim of the
cabinet.

3
INSTALLATION
ASSEMBLY
The Pressureless Cooker is factory-mounted on a cabinet base containing either a steam boiler or direct
steam connection controls for the cooker. The assembled unit is shipped bolted to a skid, with cabinet
feet in a separate container. Steps required for assembly are as follows:
1. Remove the four bolts that fasten the equipment frame to the skid.
2. Install feet in threaded mounting locations of the cabinet frame.
3. Mount the four pan support racks in brackets and studs inside cooking compartments.
4. Attach panels to lower cabinet. Detailed instructions are enclosed with the panels.
5. Attach the drip trough on studs located on the face of the unit.
SETTING IN PLACE
Level the unit in final location by turning the adjustable feet. Using the cabinet top as a reference, obtain
level adjustment left-to-right and front-to-back.
MECHANICAL CONNECTIONS
Since the Pressureless Cooker is interconnected at the factory to the steam boiler or direct steam
plumbing, no field connections to the cooker are required. All electrical and plumbing connections are
routed to the steam boiler cabinet through the 6-inch-high space between the floor and the bottom
edge of the cabinet frame. Connection locations for the cooker mounted on steam boilers of electric,
gas, and steam coil utility and direct-connected steam are shown in separate installation instructions for
each.
WATER CONNECTIONS
Before connecting water to this unit, have water supply analyzed to make sure that hardness is no
greater than 2.0 grains per gallon and pH level is within the range of 7.0–8.5. Water that fails to meet
these standards should be treated by the installation of a water conditioner.
EQUIPMENT FAILURE CAUSED BY INADEQUATE WATER QUALITY IS NOT COVERED UNDER WARRANTY.
CAUTION: PVC or CPVC are not acceptable materials for drains.
INSTALLATION CHECK-OUT
Check-out procedures for the cooker mounted on steam boilers of electric, gas, and steam coil utility or
direct-connected steam are given in separate installation instructions for each. Refer to Cooker Check-
Out on next page for the correct procedure. If the cooker fails to perform as described, consult the
Trouble-Shooting Guide for corrective action. If difficulty arises with the boiler, reference the separate
service and parts manual for that equipment.
Before making this check-out, the operator must be thoroughly familiar with the operating procedures
and with the function of each control. Refer to the section on Operation and Figure 2, Controls and
Indicators for identification of controls required in the following procedures.

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Initial Control Settings
Before beginning the start-up procedures for the cooker, the instruction plate and service manual for
the steam boiler must be consulted and all start-up procedures completed to supply 15 PSI steam to the
steam inlet line for the cooker.
1. All steam boiler controls are in the operating mode and 15 PSI steam is applied to the cooker
inlet plumbing.
2. Cooker timers for both compartments (see Figure 2 on page 9) are in the OFF position.
3. Cooker compartments are empty of all information materials, pan supports are mounted in
place, and doors are open.
Cooker Check-Out
The cooker check-out procedures are as follows:
1. With the doors open set timers to about the “4-minute” position. Observe that indicator lights
are off and steam does not enter compartments.
2. Close cooker compartment doors. Observe that indicator lights turn on, and steam can be heard
rushing into the compartment simultaneously with the door closing.
3. Observe the boiler drain line for passage of steam into the open floor drain. Correct steam
condenser operation is evidenced by presence of water flowing from the drain line.
4. Observe cooker operation for several minutes. Operation is correct if timer dials begin to rotate
after a short delay period required for preheating. After the delay period plus the “4-minute”
initial setting, the timer dials will return to the “0-Minute” position, at which a buzzer sounds.
The buzzer is silenced by turning the dial to the OFF position.
Shut-Down Procedure
No shut-down procedure is required for the Pressureless Cooker except to check that all timer dials (2)
are in the OFF position and the compartment doors are open. Consult the steam boiler instruction plate
and complete the shut-down procedures for the boiler.
REVERSING THE DOORS
The Pressureless Steam Cooker has a reversible cooking compartment door. This section contains
instructions for reversing this door.
1. Turn off power to the unit.
2. Open the cooking compartment door
3. Remove the two screws that attach the top hinge to the front of the unit.
4. Slide the door upwards, off the bottom hinge.
5. Remove the two screws that attach the bottom hinge to the front of the units.
6. Remove the right and left side panels by unscrewing the 1 screw on each panel and sliding the
panel down.

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7. Remove the door interlock assembly by unscrewing the two nuts that hold it in place (assembly
is attached to the screws in the top right hinge mounting holes, see Figure 1 on page 6).
8. Remove the four screws in the right side hinge mounting holes and install them in the left side
hinge mounting holes (where the hinges were originally mounted).
9. Using the nuts removed in step #6, reinstall the door interlock assembly onto the 2 screws in the
lower left hinge mounting holes (see Figure 1 on page 6) with by moving the assembly over the
cooking cavity to the other side of the unit. Rotate the door interlock assembly 180° for
installation, so that the switch is now facing up.
10. Reinstall the top hinge and screws into the right lower hinge mounting holes. Rotate the hinge
180° for installation, so that the pin which the door rides on is now facing up. The hinge must be
rotated because it will now function as the bottom hinge. DO NOT COMPLETELY TIGHTEN THE
HINGE MOUNTING SCREWS YET. These will be used later for adjusting the door.
11. Remove the door latch assembly from the face of the unit. The 2 nuts mounting the door latch
are located behind the face of the unit and must be accessed where the right side panel was
removed.
12. Remove the two white hole plugs from the left door latch mounting holes, and insert them into
the right door latch mounting holes (where the door latch assembly was originally mounted).
13. Rotate the door latch assembly 180°, and install into the left door latch mounting holes.
NOTE: Each stud on the latch assembly should have a plastic washer, a spring, a plastic washer and a
Nyloc type nut.
14. To adjust the tension of the door latch, tighten both nuts down until the springs are fully
compressed, then back each nut off 1-1/2 turn.
15. Rotate the door 180° for mounting.
16. Slide the remaining hinge into the top door bearing.
17. Slide the door and hinge assembly down onto the hinge which you have already mounted to the
front of the unit. Use the two screws to mount the top hinge into the right upper hinge
mounting holes. DO NOT COMPLETELY TIGHTEN THE HINGE MOUNTING SCREWS YET.
18. Slowly push the cooking compartment door closed until it is latched.
19. The cooking compartment door can now be raised, lowered, and/or rotated into position by
bumping it with the palm of your hand or by using a small rubber mallet.
20. First, check the alignment at the front of the door by making sure that the striker in the door is
centered with the latch mechanism on the front of the unit.

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21. Square the door to the unit by raising or lowering the hinge side of the door, keeping the latch
centered with the striker.
22. Visually inspect the door. Be sure that the door is square to the unit, the striker is centered with
the latch, and the gasket is in contact with the entire lip of the cooking compartment.
23. Gently open the cooking compartment door, taking care not to move it out of position.
24. Tighten all 4 door hinge bracket mounting screws.
25. Close and visually inspect the door again, as described in step 22.
26. Reinstall the left and right side panels, using the screws for each panel.
Figure 1, Typical Door Layout

7
OPERATION
OPERATING CONTROLS AND INDICATORS
The controls and indicators required to operate the Pressureless Steam Cooker are listed in table on
page 9, together with a short functional description of each. Figure 2 on page 9 shows the physical
location of each control and indicator.
OPERATING PROCEDURES
The ST-24 Pressureless Steam Cooker defrosts frozen foods and cooks fresh and defrosted foods. Each
cooking compartment permits selection of continuous (constant steam) cooking or timed (0–60
minutes) cooking. Instructions for operation are included in this section. Consult Test Kitchen Bulletin for
detailed cooking information.
Steam Source Operation
The Pressureless Cooker is supplied mounted on a cabinet containing either a steam boiler or controls
for direct-connected steam. Manual controls are accessed by opening the cabinet door. The start-up
procedure for the steam source is completed once before each daily operating period of the cooker. (For
steam boilers, see instruction plate.)
Preheating
Before each initial operation of the cooker, and at any other time when the cooking compartment is
cold, a 1-minute preheating period is required. To preheat the cooker, put steam source into operation
and proceed as follows:
1. Close cooking compartment door.
2. Set 60-Minute Timer Dial (1) to “1-minute” setting.
NOTE: Total elapsed preheating time equals the timer setting plus a short delay period needed to active
a thermostatic switch included in the controls.
3. Turn off buzzer, which sounds to indicate cooking is complete, by setting the Timer Dial (1) to
OFF position.
Cooking
Before loading the cooker, be sure compartment is hot. Refer to Preheating Section for instructions.
1. Slide pans of food into cooking compartment pan supports.
2. Close cooking compartment door.
3. Set timer cooking time:
a. CONSTANT STEAM—for continuous cooking
b. 60-MINUTE TIMER—for timed cooking.
4. Set appropriate timer to the required cooking time (Refer to Facts on Parade on page 10).
5. Turn off buzzer, which sounds to indicate cooking is complete, by setting timer dial (1) to the
OFF position.

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6. Open door slightly at first letting most of the steam out of the compartment and then fully open
the door.
7. Unload by sliding pans of food from pan supports, taking care to avoid hitting compartment
opening.
Shut-Down Procedure
No shut-down procedure is required for the cooker except to check that both timer dials (1) are in the
OFF position and that both compartment doors are open. When all cooking has been completed for the
day, the steam source must be shut off. (For steam boilers, see instruction plate.)
CAUTION:
When the unit is not in use, leave the cooking compartment door slightly ajar to prolong the life of the
door gasket.
Cleaning
After each period of daily operation (more frequently as required to maintain cleanliness), the cooker
should be thoroughly cleaned by completing the following steps:
1. Remove left- and right-side pan supports, baffles, and drain screens by lifting up and off
mounting studs. Wash with a mild detergent. Rinse and set aside for reassembly.
2. Wash cooking compartment interior using a mild detergent and water. Rinse and dry
thoroughly.
3. Replace pan supports, baffles, and drain screens in compartment and leave door open.
DRAINAGE
Cooking Compartment Drainage
The bottom of the cooking compartment is angled slightly toward the rear of the unit. This assures that
any condensate build-up or spills will be directed toward the drain hole, which is located at the rear
bottom center of the cooking compartment. Any liquid exiting the cooking compartment runs down the
cooking compartment drain tube and into the drain line.
Drip/Spill Trough Drainage
The ST-24 Pressureless Steam Cooker has a drip/ spill trough below the cooking compartment door. It
will catch any condensate gathering on the front of the unit when the door is opened.

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Figure 2, Controls and Indicators (ST-24 Control Panel)
CONTROLS AND INDICATORS
ST-24 Control Panel
ITEM
PART NO.
DESCRIPTION
FUNCTION
1
08-6464
Timer/Constant Steam
Controls cooking up to 60 minutes or uses constant
operation.
2
10-5052
Indicator Light (Red)
Indicates cooking is in operation.
3
08-6429
Digital Timer
Control cooking up to 60 minutes or uses constant
operation.
4
08-6551
Mode Switch
Constant steam / Timer.
5
08-6549
Compartment Switch
Top and bottom cavity or kettle/BTM take-off.

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TEST KITCHEN BULLETIN
Model ST-24 Pressureless Steam Cooker
Facts on Parade
1. Frozen vegetables should always be cooked in perforated 12” x 20” x 2-1/2” pans 7-1/2 lbs. (34
kg) maximum per pan.
2. Frozen entrees should be underlined with a perforated pan for best results. If they are defrosted
first, the heating time will be decreased.
3. Fresh foods may also be cooked in this unit. Vegetables and other foods where the stock is not
to be retained should be cooked in perforated 12” x 20” x 2-1/2” pans for the most nutritious
results.
4. There is a thermostatic time delay built into this unit which adapts the unit to the proper
cooking time. This means that the total time will usually be longer than the time setting.
5. There is a safety interlock switch on the door which shuts off the steam each time the door is
opened if the unit is in the cooking cycle.
6. Both compartments may be filled and timers set simultaneously.
7. Total cooking time will vary depending on the load, even though the timer setting is the same.
8. All foods, except cakes and pastry, can be cooked in a steam cooking unit.
9. Steam cooked meals have greater nutritional value since they retain most of their vitamins and
minerals.
10. Because foods are cooked faster by the higher temperatures of steam cooking, they can be
prepared closer to serving time, insuring maximum freshness.
11. Steam cooked foods have a higher percent yield more portions per dollar spent.
12. Food may be served from the same pan in which it is steam cooked, thus reducing food
breakage since there is no extra handling or transferring of food from cooking pans to serving
pans. It also reduces pot washing tasks.
13. Some important advantages of steam cooking are labor saving, reduced operating costs, space
saving, and the lifting of heavy stock pots is eliminated.
14. Rice and spaghetti products, if thoroughly wet at the start of the cooking process are very easily
prepared.
15. Food such as potatoes, poultry, seafood, and some meats may be blanched in the steam cooker,
thus reducing the total cooking time and grease absorption.
16. Fuel is used only when the steam cooking unit is in operation.
17. The steam cooker will loosen foods burned on pans making washing easier.
18. Solid pans are recommended when liquid is to be retained and perforated pans when the liquid
is not to be retained.
19. Eggs may be cooked out of the shell if they are to be chopped which eliminates peeling after
steaming.
20. The steam cooker can be opened during the cooking period to add or remove items. If any time
is lost, an adjustment may be made on the timer.
21. Steam cooking information, including recommended pan size and type, weight per pan, cooking
times and pan yields are given on the following pages of this bulletin.

11
The ST-24 Pressureless Cooker is a two compartment unit. Each compartment holds ten 12” x 20” x 2-
1/2” or six 12” x 20” x 4” pans. This unit enables the cook to prepare foods close to the time of service.
The cooking times given are timer settings and should be set in a preheated compartment. There is a
thermostatic time delay in each compartment that adjusts the total time depending on the temperature
and amount of the food. Therefore the total time will be greater than the timer setting. At the end of
the timer cooking cycle the buzzer will sound, steam will stop flowing and the food can be removed.
COOKING GUIDE
Frozen Vegetables
ITEM
Approx. Frozen
WT. Per Pan
Recommended
12” x 20” (1/1)
Perforated Pan
NO. of
Pans
Timer
Settings in
Minutes
Approx. NO.
Cooked Servings
Per Pan
Lbs.
kg
Asparagus,
Spears
7-1/2
3.4
2-1/2” (65mm)
10
12-15
30
3oz.
(85g)
Green Beans,
Regular
6
2.7
2-1/2” (65mm)
10
10-15
25
3oz.
(85g)
Green Beans,
French Cut
6
2.7
2-1/2” (65mm)
10
5-7
25
3oz.
(85g)
Beans,
Lima
7-1/2
3.4
2-1/2” (65mm)
10
12-15
30
3oz.
(85g)
Broccoli
6
2.7
2-1/2” (65mm)
10
4-6
25
3oz.
(85g)
Brussels
Sprouts
7-1/2
2.7
2-1/2” (65mm)
10
10-15
30
3oz.
(85g)
Carrots
6
2.7
2-1/2” (65mm)
10
10-15
25
3oz.
(85g)
Cauliflower
6
2.7
2-1/2” (65mm)
10
7-12
25
3oz.
(85g)
Corn,
Cut
7-1/2
3.4
2-1/2” (65mm)
10
8-12
30
3oz.
(85g)
Vegetables,
Mixed
7-1/2
3.4
2-1/2” (65mm)
10
8-12
30
3oz.
(85g)
Peas,
Loose
7-1/2
3.4
2-1/2” (65mm)
10
3-5
30
3oz.
(85g)
Spinach,
Defrosted
9
4
2-1/2” (65mm)
10
7-12
30
4oz.
(115g)
Squash,
Defrosted
12
5.4
2-1/2” (65mm)
10
7-12
50
3oz.
(85g)
Frozen Prepared Entrees
ITEM
Approx. Frozen
WT. Per Pan
Recommended
12” x 20” (1/1)
Perforated Pan
NO. of
Pans
Timer
Settings in
Minutes
Approx. NO.
Cooked Servings
Per Pan
Lbs.
kg
Lobster Tails
6-8oz.
(170-255g)
7-8
3.2-3.6
2-1/2” (65mm)
10
15-25
15
6oz.
(170g)
Shrimp,
C.D.P.
16-20
7-9
2-1/2” (65mm)
10
8-11
75
3oz.
(85g)

12
ITEM
Approx. Frozen
WT. Per Pan
Recommended
12” x 20” (1/1)
Perforated Pan
NO. of
Pans
Timer
Settings in
Minutes
Approx. NO.
Cooked Servings
Per Pan
Lbs.
Kg
Shrimp,
Green
16-20
7-9
2-1/2” (65mm)
10
11-15
50
3oz.
(85g)
Bulk Pack,
Frozen
3-1/2 -4
1.6-1.8
2-1/2” (65mm)
10
35-45
10
6oz.
(170g)
Bulk Pack,
Defrosted
3-1/2 -4
1.6-1.8
2-1/2” (65mm)
10
25-35
10
6oz.
(170g)
Fresh Vegetables
ITEM
Approx.
WT. Per Pan
Recommended
12” x 20” (1/1)
Perforated Pan
NO. of
Pans
Timer
Settings in
Minutes
Approx. NO.
Cooked Servings
Per Pan
Lbs.
kg
Green Beans,
Snap or Wax
6
2.7
2-1/2” (65mm)
10
18-22
25-30
3oz.
(85g)
Beets,
2” Ø (50mm)
7-1/2
3.4
2-1/2” (65mm)
10
40-50
30-35
3oz.
(85g)
Broccoli, Stalks
1/2”-3/4”
(12-20mm)
6
2.7
2-1/2” (65mm)
10
14-18
25-30
3oz.
(85g)
Carrots,
Sliced
9
4
2-1/2” (65mm)
10
18-21
35-40
3oz.
(85g)
Cauliflower,
Trimmed 1-1/2
–2” (38-50mm)
6
2.7
2-1/2” (65mm)
10
12-16
30-35
3oz.
(85g)
Corn on Cob,
Husked
1 doz.
2-1/2” (65mm)
10
10-15
12
Cabbage, Head
Cored 1/4-1/6
5
2.25
2-1/2” (65mm)
10
14-18
15-20
4oz.
(115g)
Onions,
2” Ø (50mm)
6
2.7
2-1/2” (65mm)
10
20-25
25-30
4oz.
(115g)
Peas,
Shelled
5
2.25
2-1/2” (65mm)
10
5-6
25-30
3oz.
(85g)
Potatoes,
French Fry Cut
10
4.5
2-1/2” (65mm)
10
10-21
50
3oz.
(85g)
Potatoes,
Regular Cut
3” (75mm)
10
4.5
2-1/2” (65mm)
10
35-40
50
3oz.
(85g)
Spinach,
Cleaned Cut
3
1.4
2-1/2” (65mm)
10
3-5
10-12
3.75 oz.
(105g)
Squash,Summer
1”Slices (25mm)
7
3.2
2-1/2” (65mm)
10
7-10
30-35
3oz.
(85g)
Squash, Winter
Peeled
9
4
2-1/2” (65mm)
10
10-15
25-30
3oz.
(85g)
Turnip,
Diced
5
2.25
2-1/2” (65mm)
10
28-32
20-25
4oz.
(115g)

13
Canned Vegetables
ITEM
Approx.
WT. Per Pan
Recommended
12” x 20” (1/1)
Perforated Pan
NO. of
Pans
Timer
Settings in
Minutes
Approx. NO.
Cooked Servings
Per Pan
Lbs.
kg
Vegetables,
Canned
7
3.2
2-1/2” (65mm)
10
5-10
25-30
3oz.
(85g)
Meat –Poultry –Fish
ITEM
Approx.
WT. Per Pan
Recommended
12” x 20” (1/1)
Perforated Pan
NO. of
Pans
Timer
Settings in
Minutes
Approx. NO.
Cooked Servings
Per Pan
Lbs.
kg
Chicken,
Cut Up
8
3.6
2-1/2” (65mm)
10
20-30
15-20
Protein
2oz.
(55g)
Chicken,
Whole 4 lbs.
3 Each
4” (100mm)
10
45-50
25-30
Protein
2oz.
(55g)
Fowl,
Whole 5 lbs. +
2 Each
4” (100mm)
10
50-60
20-25
Protein
2oz.
(55g)
Fish,
Filets
3
1.4
2-1/2” (65mm)
10
10-15
12-15
2oz.
(55g)
Hotdogs
5
2.25
2-1/2” (65mm)
10
3-5
35-40
2oz.
(55g)
Hamburgers,
3oz. (85g)
5
2.25
2-1/2” (65mm)
10
18-22
20-25
Protein
2oz.
(55g)
Meatballs,
1oz. (30g) Size*
6
2.7
2-1/2” (65mm)
10
20-25
20-25
Protein
2oz.
(55g)
Meatloaf*
15
6.8
2-1/2” (65mm)
10
40-50
50-60
Protein
2oz.
(55g)
Pork Chops,
Loin Bone
4oz. (115g)
6
2.7
2-1/2” (65mm)
10
25-30
24
Protein
2oz.
(55g)
Sausage,
1-1/2oz. (45g)
6
2.7
2-1/2” (65mm)
10
18-21
18-20
2oz.
(55g)
Turkey,
On Carcass
20-22
9-10
2-1/2” (65mm)
1
2 to 2-1/2
Hours
50-60
Protein
2oz.
(55g)
Turkey,
Off Carcass
10-12
4.5-5
2-1/2” (65mm)
10
1 to 1-1/4
Hours
55-65
Protein
2oz.
(55g)
*Raw weight for Meatballs and Meatloaf includes hamburg and extenders and yields 2 oz. (55 g) protein
plus extenders or 3 oz. (85 g) total portion.
Miscellaneous
ITEM
Approx.
WT. Per Pan
Recommended
12” x 20” (1/1)
Perforated Pan
NO. of
Pans
Timer
Settings in
Minutes
Approx. NO.
Cooked Servings
Per Pan
Lbs.
Lbs.
Eggs,
In Shell
3 Doz.
2-1/2” (65mm)
10
9-11
36
1 Egg
Each
Eggs,
Out of Shell
4 Doz.
2-1/2” (65mm)
10
6-8
48
1 Egg
Each
Rice –
Bulletin 16
4
1.8
2-1/2” (65mm)
10
18-22
60-65
3oz.
(85g)
Spaghetti –
Bulleting 13
3
1.4
4” (100mm)
10
18-22
40-45
4oz.
(115g)

14
PRINCIPLES OF OPERATION
GENERAL
The ST-24 Pressureless Steam Cooker consists of two identical cooking compartments, one above the
other, in a single cabinet assembly. Each compartment is fitted with independent electrically controlled
steam circuits and spring-loaded, self-sealing doors with slam action latches. Compartments can be used
separately or simultaneously for either constant steam or 60-minute timing. The principles of operation
in this section include an explanation of steam, steam condensing, and electrical circuits and their
functioning.
PLUMBING CIRCUITS
The plumbing circuits consist of the piping, steam solenoid valves, orifice, drain, and cold water
condenser required to provide controlled steam application to the cooking compartments. A simplified
diagram of these circuits is shown in Figure 3 on page 15.
NOTE: Figure 3 on page 15 is strictly a pictorial schematic diagram and is not intended to show the
actual configuration of the plumbing. All components are shown in correct relationship with each other.
However, the diagram does not show their actual locations or position within the cooker.
As shown in the diagram, steam inlet and exhaust connections are connected at the factory directly into
a steam boiler or direct-connected steam plumbing enclosed within the base cabinet on which the
cooker is mounted. The boiler (or direct-connected steam control system) is equipped to supply
constant, regulated steam at 14–15 PSI. Steam exhaust, having been reduced to water by the cold water
condenser, is directed into the boiler (or direct-connected steam control) drain system.
Steam inlet lines for compartments are equipped with normally closed solenoid valves operated by the
electrical control circuits. The inlet valves are opened whenever the compartment control circuit is
activated by use of the 60-minute timers.
Steam Inlet Line
A steam supply line is plumbed from the boiler output (or direct-connected steam control) to a 1/2-inch
barb fitting connected to the input sides of both steam inlet solenoid valves. When a cooking
compartment is not in use, the valve for the compartment remains closed to prevent steam from
entering. During operation, the appropriate inlet solenoid valve is opened by activation of the control
circuit. Steam is projected onto the surface of pans of food loaded into the compartment by an orifice
located inside the compartment. Steam continues to flow through the compartment in this manner until
the control circuit closes the solenoid valve.
Steam Exhaust and Drain Lines
Perforated strainers at the drain line openings inside each compartment allow only steam,
condensation, and liquid cooking drainage to enter. Prior to discharge into the boiler drain system,
steam is converted to water by the cold water condensing systems for each compartment.
Steam Exhaust Condensing System
The steam condensing system consists of the identical, two-position, normally closed cold water
solenoid valves, with outlet sides connected into the exhaust plumbing for each cooking compartment.
A spray nozzle directs cold water about the inside of the drain lines to increase cold water contact with

15
exhausted steam. Valve inlet sides are connected remote from the supply line of the steam boiler (or
direct-connected steam plumbing). The valves respond to a thermostatic switch located inside the
compartment. When the timer starts the cold water solenoids will energize.
Figure 3, pictorial Diagram, Steam and Water Circuits (Model ST-24)
ELECTRICAL CIRCUITS
The electrical circuits of the cooker control the power to activate timer motors and energize solenoid-
operated valves and circuits, which in turn control application of steam to the cooking compartment and
condensation of steam from the exhaust line. The cooker operates on 120V, 2 amp, 60Hz electrical
service connected to all circuits from the circuits of the steam boiler (or direct-connected steam
controls) contained within the cabinet on which the cooker is mounted. Power is supplied to the control
circuit at all times when the shut-off device (Circuit Breaker) for the unit (installed by a certified
Electrician) is in the ON position.
Control Circuit Components
A brief description of the electrical circuit elements follows.
60 Minute Timer/Constant Steam
The timer contains a 120-volt AC synchronous motor that drives a timing dial through a gear reduction
and clutch mechanism. The timer dial is manually set for any interval of operation from 0 to 60 minutes
or constant steam as read on the calibrated dial face. The manual rotation of the dial moves the
common element (1) of the timer switch from the neutral (OFF) position to contact (3), which connects
with the steam inlet solenoid valve operating circuit.
The cooker is placed into automatic operation with the setting of the timer dial. Its timing cycle,
however, is automatically delayed by a thermostatic switch, which assures operating temperature is

16
achieved before the timer motor begins to “time out.” When the timer motor has operated for the
preset duration, the common element is transferred to contact (4), returning the inlet solenoid valve to
the closed position and energizing the buzzer. Contact to the buzzer circuit remains closed until the dial
is manually turned to the OFF position, returning the common element (1) of the timer switch to the
neutral position.
Indicator Lights
An indicator light is included for both compartments. The light remains on (red) at all times when the
coinciding timer dial is set and the door interlock switch is closed. The light turns off at the end of the
timed cooking duration or when the set time has elapsed.
Buzzer
The buzzer is an alarm device that operates by oscillation of a striker against the core of an
electromagnet. When the 60-minute timer dials reach the “0-Minute” position, the buzzer coil is
energized to sound the buzzer. Movement of the timer dial to the OFF position opens the contact to the
buzzer coil to shut it off.
Door Interlock Switch
The interlock switch is a single-pole proximity switch with normally open contacts. The switch is
operated by the proximity of a magnet within the door. When the door is open, the switch contacts
remain in the open position. When the door is closed and securely latched in place, the magnet is near
the switch to close the contacts.
Connected between the operating contact (3) of the timers and the steam inlet solenoid valve, the door
switch acts as a protective device to interrupt valve operation unless the door is closed.
Thermostatic Switch
The thermostatically operated switch is a two-position, normally open switch mounted on the cooking
compartment. The switch functions to activate the cold water solenoid valves of the steam condensing
system and to delay timer motor operation until the compartment temperature reaches 195°F, thus
assuring that cooking temperature exists throughout the timed duration.
Digital Timers (Optional)
The timer controls the steam to the cavity by either a constant steam setting or a used defined timer
that will be programmed by the user into the timer
Kettle Switch (Optional)
The Kettle Switch will allow the user to set the mode of the steam. The user can either set the switch so
that top and bottom cavity are in use at the same time. Or the bottom cavity and a separate direct
connected kettle can be used at the same time.

17
TROUBLE-SHOOTING
GENERAL
The information in this section is intended to assist both the operator and service personnel in locating the
general source of problems that may occur with the cooker. Before following any of the procedures given
in this section, the operator should be thoroughly familiar with the operating instructions and the function
of all controls that are described in the Operation section, pages 7-11. If the problem cannot be readily
corrected, the operator should contact the nearest Market Forge service agency for assistance.
Trouble-Shooting Guide
A trouble-shooting guide for use by service personnel is given in the table below.
Electrical Fault Isolation
Correction of an electrical failure first requires isolation of the fault to a single circuit or component. In
most cases, the nature of the failure and its effect upon the operation of the cooker will be sufficient to
narrow it down to one or more circuit elements. The Electrical Fault Isolation table on page 19 is provided
as a guide for isolating electrical faults.
Electrical Trouble-Shooting Procedures
Before performing the trouble-shooting procedures in this section, the serviceman must be familiar with
the function of all controls as described in the Operation section as well as with the Principles of
Operation described in Principles of Operation section, pages 14-16.
GENERAL TROUBLE-SHOOTING GUIDE TABLE
PROBLEM
PROBABLE CAUSE
REMEDY
1.
Indicator light fails to
light with timer set.
a.
Power to cooker off.
a.
Locate external circuit breaker for
incoming power and place in ON
position.
b.
Door interlock switch
contacts not closed.
b.
Shut cooker door to close switch
contacts. Check alignment of door with
switch.
c.
Door interlock switch
faulty.
c.
Replace switch. See Door Interlock
Switch on page 20.
d.
Indicator light burned out.
d.
Replace light.
e.
Faulty timer contacts.
e.
Replace timer. See 60-Minute Timer
on page 19.
f.
Faulty wiring.
f.
Inspect condition of wire and tightness
of all connections. Correct as needed.
2.
Steam fails to enter
cooking compartment
with indicator light on.
a.
Faulty steam solenoid
valve.
a.
Replace valve. See Steam Solenoid
Valves on page 20.
b.
Faulty wiring.
b.
Inspect condition of wire and tightness
of all connections. Correct as needed.
3.
Steam enters
compartment
continuously.
Timer dial not turning.
a.
Constant steam position.
a.
Move knob to timing location.
b.
Faulty thermostatic
switch.
b.
Replace switch. See Cooking
Compartment Thermostatic Switch on
page 20.
c.
Faulty timer motor.
c.
Replace timer. See 60-Minute Timer
on page 19.
d.
Faulty steam solenoid
valve.
d.
Replace valve. See Steam Solenoid
Valves on page 20.
e.
Faulty wiring.
e.
Inspect condition of wire and tightness
of all connections. Correct as needed.

18
GENERAL TROUBLE-SHOOTING GUIDE TABLE CONTINUED
PROBLEM
PROBABLE CAUSE
REMEDY
4.
Steam continues to
flow into compartment
and/or buzzer fails to
sound at end of timer
setting.
a.
Timer contacts faulty.
a.
Replace timer. See 60-minute timer on
page 19.
b.
Buzzer faulty.
b.
Replace buzzer. See Buzzer on page
21.
c.
Faulty wiring.
c.
Inspect condition of wire and tightness
of all connections. Correct as needed.
5.
Steam flows
continuously from
boiler (or direct
connected steam
control) drain line with
cooker in operation.
a.
Cold water not
connected.
a.
Turn on external shut-off valve.
b.
Faulty thermostat.
b.
Replace thermostat. See Cooking
Compartment Thermostatic Switch on
page 20.
c.
Faulty cold water
solenoid.
c.
Replace valve.
d.
Faulty wiring.
d.
Inspect condition of wire and tightness
of all connections. Correct as needed.
The electrical trouble-shooting procedures that follow require access to components and terminals of
the electrical control panel shown in Figure 10, on page 32. Electrical controls are reached by removing
screws that fasten the control panel to the frame. The panel may be pulled forward for testing while
interconnected to the cooker circuits or disconnected at the pin connection for complete removal and
repair.
Incoming Power
Before trouble-shooting any of the electrical parts or assemblies, verify that power is being supplied to
the cooker. Incoming power is connected at the boiler (or direct-connected steam) control box located in
the base cabinet. With power connected to the cooker, an AC voltmeter is used to measure 120 volts
across L1 and L2. If 120 volts is present, and the cooker will not operate, the fault lies within the
electrical circuits of the cooker.
Electrical Inspection
The first step in any electrical trouble-shooting procedure is a thorough physical inspection of all wiring
connections. To access electrical components, remove the control panel as explained in Exterior Panel
Removal on page 27.
WARNING:
Before removing control panel or checking connections and wiring, be sure that the circuit breaker for
incoming power is OFF. When power is supplied, all exposed terminals of the control panel carry 120
volts.
Check all wiring connections by hand to assure that both ends of all connection points are tightly
secured. Use a screwdriver to tighten connection points. If necessary, visually inspect all quick-
disconnect terminals for evidence of corrosion. Terminals in this condition should be separated, cleaned
with emery cloth until shiny, and tightly reconnected.