is a registered trademark of Middleby Marshall, Inc. All rights reserved.
Middleby Cooking Systems Group 1400 Toastmaster Drive Elgin, IL 60120 USA (847)741-3300 FAX (847)741-4406
1
NOTICE:
Owner's Operating and Installation Manual should be given to the user. The operator of the oven should
This
be familiar with the functions and operation of the oven.
This manual must be kept in a prominent, easily reachable location near the oven.
ENGLISH
Gas ovens are designed for use with EITHER natural gas OR liquid propane gas, as specified on the serial plate.
Where permitted by local and national codes, the oven can be converted from natural gas to propane operation,
or from propane to natural gas operation. This conversion is described in the Installation section of this Manual.
The conversion requires the installation of the appropriate Middleby Marshall Gas Conversion Kit.
It is suggested to obtain a service contract with a Middleby Marshall Authorized Service Agent.
WARNING
POST, IN A PROMINENT LOCATION, THE EMERGENCY TELEPHONE NUMBER OF YOUR LOCAL GAS
SUPPLIER AND INSTRUCTIONS TO BE FOLLOWED IN THE EVENT YOU SMELL GAS.
Instructions to be followed in the event the user smells gas shall be obtained by consulting the local gas
supplier. If the smell of gas is detected, immediately call the emergency phone number of your local Gas
Company. They will have personnel and provisions available to correct the problem.
FOR YOUR SAFETY
Do not store or use gasoline or other flammable vapors or liquids in the vicinity of
this or any other appliance.
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.
IMPORTANT
An electrical wiring diagram for the oven is located inside the machinery
compartment.
IMPORTANT
It is the customer's responsibility to report any concealed or non-concealed damage
to the freight company. Retain all shipping materials until it is certain that the
equipment has not suffered concealed shipping damage.
NOTICE: CONTACT YOUR MIDDLEBY MARSHALL AUTHORIZED SERVICE AGENT TO PERFORM MAINTENANCE
AND REPAIRS. AN AUTHORIZED SERVICE AGENCY DIRECTORY IS SUPPLIED WITH YOUR OVEN.
NOTICE: Using any parts other than genuine Middleby Marshall factory manufactured parts relieves the manufacturer of
all warranty and liability.
NOTICE: Middleby Marshall (Manufacturer) reserves the right to change specifications at any time.
NOTICE: The equipment warranty is not valid unless the oven is installed, started and demonstrated under the supervision
of a factory certified installer.
Retain This Manual For Future Reference
Middleby Cooking Systems Group 1400 Toastmaster Drive Elgin, IL 60120 USA (847)741-3300 FAX (847)741-4406
GAS OVEN, 220-230V, 50Hz, 1 Ph......................... 24
3
SECTION 1 - DESCRIPTION
I.OVEN USES
PS300 Series Ovens can be used to bake and/or cook a
ENGLISH
wide variety of food products, such as pizza, pizza-type
products, cookies, sandwiches and others.
II. OVEN COMPONENTS - see Figure 1-1.
A. Crumb Pans: Catch crumbs and other material that drop
through the conveyor belt. One crumb pan is located
underneath each end of the conveyor.
B.Conveyor Drive Motor: Moves the conveyor.
C. Conveyor: Moves the food product through the oven.
D. End Plugs: Allow access to the oven's interior.
E. Serial Plate: Provides specifications for the oven that affect
installation and operation.
F.Window: Allows the user to see and access food products
inside the baking chamber.
G. Machinery Compartment Access Panel: Allows access
to the oven's interior components. No user-servicable
parts are located in the machinery compartment.
H. Control Compartment Access Panel: Allows access to
the control components. No user-servicable parts are
located in the control compartment.
I.Control Panel: Location of the operating controls for the
oven.
Not Shown:
J. Eyebrows (on ovens so equipped): Can be adjusted to
various heights to prevent heat loss into the environment.
K. Conveyor End Stop: Prevents food products from falling off
the end of the moving conveyor.
L. Gas Burner (gas ovens) or Heating Elements (electric
ovens): Heats air, which is then projected to the air fingers
by the blowers.
M. Blowers: Fans that project hot air from the burner to the air
fingers.
N. Air Fingers: Project streams of hot air onto the food product.
Lower oven, with top and legs1143mm1143mm
Upper oven, with stand and top1638mm1638mm
Double oven (two-stack)2089mm2089mm
Overall Depth (including rear shrouds and front window)1194mm1397mm
Overall Length2299mm2299mm
Conveyor Width, Single Belt Ovens813mm1016mm
Conveyor Width, Split Belt Ovens2 x 381mm2 x 483mm
Recommended Minimum Clearances
Rear of oven (inc. rear shrouds) to wall25mm25mm
Conveyor extension to wall (both ends)0mm0mm
Table 1-2: General specifications (per oven cavity)
Oven Model VoltageCircuit VoltagePhaseFreq.Draw *PolesWires
Gas Ovens220-230V120V (transformer)1 Ph50 Hz8A2 Pole3 Wire (1 hot, 1 neut, 1 gnd)
Electric Ovens380-400V120V (transformer)1 Ph50 Hz39A2 Pole5 Wire (3 hot, 1 neut, 1 gnd)
* CAUTION: The current draw shown in the chart above is an average value for normal operation. The initial amperage draw on oven startup
may exceed the listed value.
IMPORTANT: Additional electrical information is provided on the oven's serial plate, and on the wiring diagram inside the machinery compartment.
Table 1-4: Gas orifice and pressure specifications (per oven cavity)
WARNING - After any conversions, readjustments, or service work on the oven:
Perform a gas leak test.
Test for correct air supply, particularly to the burner blower.
Test for proper combustion and gas supply.
Check that the ventilation system is in operation.
WARNING
Keep the appliance area free and clear of combustibles.
WARNING
The oven must be installed on an even (level) non-flammable flooring and any adjacent walls must be non-
flammable. Recommended minimum clearances are specified in the Description section of this Manual.
WARNING
Do not obstruct the flow of combustion and ventilation air to and from your oven. There must be no
obstructions around or underneath the oven. Constructional changes to the area where the oven is
installed shall not affect the air supply to the oven.
NOTE
There must be adequate clearance between the oven and combustible construction. Clearance
must also be provided for servicing and for proper operation.
NOTE
An electrical wiring diagram for the oven is located inside the machinery compartment.
NOTE
All aspects of the oven installation, including placement, utility connections, and ventilation requirements,
must conform with any applicable local, national, or international codes. These codes supercede the require-
ments and guidelines provided in this manual.
5
SECTION 2 - INSTALLATION
I. INSTALLATION KIT
1
Fig. 2-1 - Installation Kit
4
3
5
ENGLISH
8
6
7
10
9
2
A. Installation kit components (one kit required per cavity)
ItemDescriptionPart NumberLower Oven w/o Top Lower Oven w/TopUpper Oven
1Legs, adjustable22450-002844--
2aConveyor End Stop - PS360/360S
2bConveyor End Stop - PS360WB (Single or Split Belt)36526111
Single Belt35000-1103111
Split Belt35509222
3Attachment Plate, upper oven35122-0049----2
4Thermocouple33812-1222
5Screw, #10-32 x 3/8"21256-0008222
6Cable Clamp27276-0001111
7Screw, #2PT 10-16 x 3/4" HWH21292-00012214
8Owner's Operating and Installation Manual46486111
9Authorized Service Agency Listing1002040111
11
B. Additional installation kit components for gas ovens
ItemDescriptionPart NumberLower Oven w/o Top Lower Oven w/TopUpper Oven
5Screw, #10-32 x 3/8"21256-0008111
7Screw, #2PT 10-16 x 3/4" HWH21292-0001222
VOID AGENCY CERTIFICATIONS
RESTRICT SERVICE ACCESS
LEAD TO INCREASED SERVICE
EXPENSES FOR THE OWNER
A. Requirements
CAUTION
CAUTION
Gas oven installations
ventilation system with electrical exhaust air sensing control.
A mechanically driven ventilation system is
RECOMMENDED for electric oven installations.
PROPER VENTILATION OF THE OVEN IS THE
RESPONSIBILITY OF THE OWNER.
REQUIRE a mechanically driven
STRONGLY
SECTION 2 - INSTALLATION
B. Recommendations
NOTE THAT THE HOOD DIMENSIONS SHOWN IN FIGURE 2
RECOMMENDATIONS ONLY. LOCAL, NATIONAL, AND
ARE
INTERNATIONAL CODES MUST BE FOLLOWED WHEN
INSTALLING THE VENTILATION SYSTEM. ANY APPLICABLE
LOCAL AND NATIONAL CODES SUPERSEDE THE
RECOMMENDATIONS SHOWN IN THIS MANUAL.
The rate of air flow exhausted through the ventilation system
may vary depending on the oven configuration and hood design.
Consult the hood manufacturer or ventilation engineer for these
specifications.
To avoid a negative pressure condition in the kitchen area,
return air must be brought back to replenish the air that was
exhausted. A negative pressure in the kitchen can cause heatrelated problems to the oven components as if there were no
ventilation at all. The best method of supplying return air is
through the heating, ventilation and air conditioning (HVAC)
system. Through the HVAC system, the air can be temperaturecontrolled for summer and winter. Return air can also be
brought in directly from outside the building, but detrimental
effects can result from extreme seasonal hot and cold
temperatures from the outdoors.
NOTE: Return air from the mechanically driven system
blow at the opening of the baking chamber. Poor oven baking
performance will result.
C. Other ventilation concerns
Special locations, conditions, or problems may require the
services of a ventilation engineer or specialist.
Inadequate ventilation can inhibit oven performance.
It is recommended that the ventilation system and duct
work be checked at prevailing intervals as specified by the
hood manufacturer and/or HVAC engineer or specialist.
must not
ENGLISH
458mm
Fig. 2-2 - Ventilation System
458mm
7
51mm
minimum
76mm
305mm
SECTION 2 - INSTALLATION
III. ASSEMBLY
A. Caster Removal
After moving the ovens in to the installation location, remove the
casters attached to each oven cavity. These casters are provided
for pre-installation movement ONLY.
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B. Stacking
If the installation will include upper ovens mounted atop lower
ovens, stack the oven cavities.
C. Stands
If the installation includes ovens that are to be mounted on
stands, assemble the ovens to the stands at this time. An
exploded view of the stand is shown in Figure 2-3.
D. Flue Vent(s)
For gas ovens, attach one flue vent to the rear wall of each oven
cavity. Use one #10-16 x 3/8" and two #10-32 x 3/4" screws for
each flue vent. These screws are provided in the Installation Kit.
Figure 2-3 - Exploded View, Oven Stand
Attachment
plates inc. w/
upper oven
installation kit
IV. THERMOCOUPLE INSTALLATION
1. Install one thermocouple sensing bulb into each of the two
holes in the rear panel of the oven, as shown in Figure 2-4.
Fasten each thermocouple in place using one of the #1032 x 3/8" screws supplied in the Installation Kit.
2. Thread BOTH sets of thermocouple leads through the
grommet and into the machinery compartment, as shown
in Figure 2-4.
3. Remove the right-side access panel of the machinery
compartment.
4. Thread the thermocouple leads through the side of the
machinery compartment as shown in Figure 2-5, and into
the electrical box (at the right-front of the machinery compartment).
5. Connect BOTH sets of thermocouple leads to the temperature controller as shown in Figure 2-6. Note that the two
thermocouples are now tied together at the temperature
controller.
6. Replace the right-side panel of the machinery compartment.
7. Repeat Steps 1-6 for any other oven cavities in the installation.
Figure 2-4 - Thermocouple Installation Locations
Thermocouples
Grommet-protected hole
Figure 2-5 - Placing the Thermocouple Leads
8=White=Positive
7=Red=Negative
R=No Connection
Ground=Shielded cable
8
Figure 2-6 - Thermocouple Lead Connections
V. CONVEYOR INSTALLATION
NOTE
Split belt conveyors can only be installed from the end of the
with the drive motor.
oven
Single-belt conveyor assemblies may be inserted into either
end of the oven. If it is to be installed from the end of the oven
without the drive motor, the drive sprocket assembly must be
removed.
To remove the drive sprocket (if necessary), loosen the set
screw on the conveyor collar as shown in Figure 2-7. Then, pull
the sprocket assembly straight out.
1. Lift the conveyor and position it in the oven as shown in
Figure 2-8.
Figure 2-8 - Inserting the Conveyor
SECTION 2 - INSTALLATION
Figure 2-7 - Removing the Conveyor Drive Sprocket
ENGLISH
Loosen conveyor collar
set screw, then pull shaft
straight out
2. Continue moving the conveyor into the oven until the frame
protrudes equally from each end of the oven (about 457mm).
3. Check that the retainers located on the underside of the
conveyor frame rest firmly against the lower end plug, as
shown in Figure 2-9.
NOTE:
Each oven has retainer clips on the bottom of the conveyor
frame, as shown in Figure 2-9. The clips are only located
on the left (drive) side of the frame.
4. When the conveyor is positioned properly, check for freedom of movement of the conveyor belt by pulling it for about
60 to 90 cm with your fingers. The conveyor
must move
freely.
5. If the drive sprocket was removed when installing the
conveyor, replace it at this time.
6. Install the drive chain between the conveyor drive sprocket
and the motor sprocket. To install the chain, it will be
necessary to lift the drive end of the conveyor slightly. The
drive motor and sprocket are shown in Figure 2-7.
7. Install the conveyor drive motor cover and tighten its hanger
screw (on the rear wall of the oven).
8. Check the tension of the conveyor belt as shown in Figure
2-10. The belt should lift between 75-100mm. DO NOT
OVERTIGHTEN THE CONVEYOR BELT.
NOTE:
If necessary, the belt tension can be adjusted by turning the
conveyor adjustment screws, located at the idler (right) end
of the conveyor. See Figure 2-10.
Figure 2-9 - Conveyor retainers
Retainer clip
Figure 2-10 - Checking the conveyor tension
75-100mm
vertical
deflection
Conveyor
tension
adjustment
screws (idler
end only)
9
SECTION 2 - INSTALLATION
9. If necessary, links can be added to or removed from the
conveyor belt to achieve the correct deflection of 75-100mm.
If links must be removed from the belt, it can be reattached
to the conveyor as follows:
a. The conveyor belt links must be oriented as shown in
ENGLISH
Figure 2-11.
b. The smooth side of the conveyor belt must face UP.
c. Connect the inside master links. Check that the links
are oriented as shown in Figure 2-11.
d. Connect the outside master links. Note that the
outside master links have right and left sides. The
right-side master link has an open hook facing you, as
shown in Figure 2-11.
e. Check for freedom of movement of the conveyor belt by
pulling it for about 60 to 90 cm with your fingers. The
conveyor must move freely.
f.Return to Step 8, above, to re-check the belt tension.
Figure 2-11 - Conveyor and Master Link Orientation
Direction
of travel
Outside master link
orientation
CORRECT
master link
position
Incorrect
master link
position
Inside master link
orientation
VI. FINAL ASSEMBLY
1. Assemble the end plugs and motor housing onto the oven.
2. Slide the conveyor extensions over the ends of the conveyor
frame. Be sure that the extension with the drive sprocket
opening is placed on the drive end.
3. Refer to Figure 2-12 for the correct location of each crumb
tray. Then, install the crumb trays underneath the conveyor
as shown in Figure 2-13. First, place the inside edge of the
tray onto the bracket attached to the end plug. Then, swing
the outside edge of the tray up and into place.
4. Press the end stop down over the edge of the conveyor
extension at the exit end of the oven. See Figure 2-13.
5. Adjust the bottom section of the legs so that the oven is
level.
Figure 2-12 - Crumb tray positions
Upper Oven
(Drive End)
Upper Oven
(Idler End)
Lower Oven
Figure 2-13 - Crumb trays, extensions, and end stop
End
stop
Conveyor extension
Conveyor frame
10
Crumb tray
VII. ELECTRICAL SUPPLY
WARNING
Authorized supplier personnel normally accomplish
the connections for the ventilation system, electric supply,
and gas supply, as arranged by the customer. Following
these connections, the factory-authorized installer can
perform the initial startup of the oven.
NOTE: All aspects of the electrical supply connection must
comply with current IEC/CEE requirements and with all
applicable local, national, and international codes.
Check the oven serial plate before making any electric supply
connections. Electric supply connections must agree with data
on the oven serial plate. The location of the serial plate is shown
in Figure 1-1 (in Section 1,
A fused disconnect switch or a main circuit breaker (customer
furnished)
MUST be installed in the electric supply line for each
oven cavity. The circuit breaker/disconnect must have 3mm
contact gaps breaking all poles of the supply. It is recommended
that this circuit breaker/disconnect have lockout/tagout capability.
The supply conductors are to be 90°C-rated copper wiring.
Additional wiring information is shown on the wiring diagrams
in Section 5,
Electrical Wiring Diagrams and inside the machin-
ery compartment of the oven.
The oven requires a ground connection to the oven ground
screw located in the electrical junction box. (The box is shown
in Figure 2-14.) The ground connection must comply with
current IEC/CEE requirements and with all applicable local,
national, and international codes. If necessary, have the
electrician supply the ground wire. Do NOT use the wiring
conduit or other piping for ground connections!
Description).
SECTION 2 - INSTALLATION
A. Additional Information - Gas Ovens
All electric supply connections are made via the electrical
junction box on the rear of the oven, shown in Figure 2-14. The
power lines then connect to the oven circuits through safety
switches located inside the machinery compartment and each
blower motor compartment. These switches interrupt electric
power to the oven when the Machinery Compartment Access
Panel is opened, OR when either of the blower or rear shrouds
is removed.
B. Additional Information - Electric Ovens
A cutout in the back wall of the machinery compartment provides
access to the electrical supply connections. See Figure 2-14.
The actual wiring connections are made at the electrical junction
box.
C. Connection
Refer to the wiring diagram inside the machinery compartment,
or in Section 5 of this Manual, to determine the correct
connections for the electrical supply lines. Connect the supply
as indicated on the wiring diagram.
If required by national or local codes, connect an equipotential
ground wire to the lug next to the
symbol. The equipotential
ground connection must meet all applicable national and local code requirements.
ENGLISH
VIII. GAS SUPPLY
CAUTION
DURING PRESSURE TESTING NOTE ONE OF THE FOLLOWING:
1. The oven and its individual shutoff valve must be
disconnected from the gas supply piping system during
any pressure testing of that system at test pressure in
excess of 3.45 kPa.
2. The oven must be isolated from the gas supply piping
system by closing its individual manual shutoff valve
during any pressure testing of the gas supply piping
system at test pressure equal to or less than 3.45 kPa.
3. If incoming pressure is over 50mbar, a separate regulator MUST be installed in the line BEFORE the individual
shutoff valve for the oven.
WARNING: To prevent damage to the control valve regulator during initial turn- on of gas, it is
open the manual shutoff valve
very slowly.
After the initial gas turn-on, the manual shutoff valve must
remain open except during pressure testing as outlined
in the above steps or when necessary during service
maintenance.
very important to
Figure 2-14 - Utility Connection Locations
Electrical
Junction Box
Gas ovens:
19mm pipe for
gas utility connection
Electric ovens:
Cutout for electrical
connection
11
SECTION 2 - INSTALLATION
A. Gas Utility Rough-In Recommendations
The following gas system specifications are STRONGLY
RECOMMENDED. Deviating from these recommendations
may affect the baking performance of the oven.
Gas Meter
ENGLISH
One or two oven cavities: 354
Three or four oven cavities: 566
l/sec
l/sec
meter
meter
Gas Line
DEDICATED LINE from the gas meter to the oven
50.8mm pipe for natural gas
38.1mm pipe for propane
Maximum length: 61m. Each 90° elbow equals 2.13m of
pipe.
B. Connection
WARNING
Some procedures in this section may require conversions, readjustments, or service on the oven's gas system.
Before performing these procedures, check that the main
gas supply valve and the circuit breaker/fused disconnect
are in the OFF ("O") position. After completing these procedures, perform a gas leak test before operating the oven.
CAUTION
The terms of the oven's warranty require all start-ups, conversions and service work to be performed by a Middleby Marshall
Authorized Service Agent. The installation, start-up and changes
required when changing from one gas type to another can be
performed ONLY by a certified professional.
NOTE: The gas supply connection should be according to
applicable ISO 228-1 or ISO 7-1 recommendations. All aspects
of the gas supply connection must comply with current IEC/CEE
requirements and with all applicable local, national, and international codes.
Check the ovens gas supply requirements before making the
gas utility connection. Gas supply requirements are listed on
the ovens serial plate.
Check the serial plate to determine the type of gas to be used
with the oven. Check that the gas type indicated matches the
local supply at the installation. If the gas type on the serial plate
does NOT match the local supply, directions for converting the
oven for use with other gases are described in
Preparation for
Use with Various Gases, in this section.
Refer to the instructions in the gas hose package (included in
the Installation Kit) before connecting the gas line. One gas line
connection method is shown in Figure 2-15; however,
compliance with the applicable standards and regulations is
mandatory.
Figure 2-15 - Flexible Gas Hose Installation
To Gas
Supply Pipe
Appliance
Connection/Male
Nipple
90°
Elbow
Full-Flow Gas
Shutoff Valve
Flexible
Gas Hose
Supply (inlet)
pressure tap
Governor
disabled for
liquid
propane (LP)
operation
Multifunction Gas Valve
Governor
enabled for
natural gas
operation
Union
Figure 2-16 - Gas Burner and Piping Assembly
Orifice
(manifold)
pressure tap
Burner Blower
High Flame
Solenoid Valve
Gas Burner
Multifunction
Gas Valve
Pilot Line
Low Flame
Bypass Line
Pilot pressure tap
12
C. Preparation for Use with Various Gases
Before proceeding to set up the oven for a specific gas, check
that the main gas supply valve and the circuit breaker/fused
disconnect are in the OFF ("O") position.
The main and pilot orifices must match the sizes shown in the
Gas Orifices and Pressure Specifications table, near the
beginning of this Section. If necessary, replace the orifices.
Refer to Part D,
Replacing the Gas Orifices.
The orifice (manifold) pressure should be adjusted to the value
shown in the Gas Orifices and Pressure Specifications table for
the specific gas type and location.
1. For Use with Natural Gas
The actual heat input to the oven must match the rated heat
input. The input to the burner can be determined using the
orifice (manifold) pressure data or by the volume supplied
using the gas meter. Both of these procedures are
described in Part F,
Adjusting the Orifice (Manifold) Pressure
and Heat Input.
If the measured input does not correspond with the rated
input (shown in the Gas Orifices and Pressure Specifications
table), check first that the correct orifices are installed. If the
orifices are correct, check and correct the supply and orifice
pressures to obtain the correct input based on the gas
meter reading.
2. For Use with Liquid Propane (LP) Gas
When using liquid gas, the converter in the multifunction
gas valve must be removed, and then replaced INVERTED
from its former position. See Figure 2-16. Inverting the
converter will disable the governor. This step is only
required if the supply pressure is below 50mbar.
Figure 2-17 - Replacing the Main and Pilot Orifices
Venturi
assembly
Pilot
orifice
Compression
nut
Pilot tube
Main
orifice
SECTION 2 - INSTALLATION
D. Replacing the Gas Orifices (if so required)
1. Replacing the Main Orifice
a. Check that the main gas supply valve and the circuit
breaker/fused disconnect are in the OFF ("O") position.
b. Open the union in the gas supply line. The union is
shown in Figure 2-16, on the previous page.
c. Refer to Figure 2-17. Unscrew the four hex screws that
hold the venturi mounting plate to the front of the
burner. Remove the gas train/venturi assembly from
the oven.
d. Remove the two 1/2" nuts that secure the gas train to
the venturi mounting plate.
e. Remove the main orifice using an 11/16" wrench.
f.Install the new orifice.
2. Replacing the Pilot Orifice
NOTE: All natural gases use the same size pilot orifice
(0,635mm), as do all liquid propane (LP) gases (0,381mm).
Because of this, it is not normally necessary to replace the
pilot orifice unless converting the oven from natural to
propane, or from propane to natural, operation.
a. Refer to Figure 2-17. Unscrew the pilot tube
compression nut and slide it out of the way. Pull the
tube from the fitting to expose the pilot orifice.
b. Remove the pilot orifice.
c. Slip the new pilot orifice into the pilot tube.
d. Push the pilot tube back into place until it bottoms, and
hold it in place. Slide the compression nut back into
place and engage the threads. Tighten the nut to a
snug fit with your fingers.
e. Gently tighten the nut one complete turn with a wrench.
DO NOT OVERTIGHTEN THE COMPRESSION NUT.
3. Replacing the Bypass (Low Flame) Orifice
a. Refer to Figure 2-16. Note the locations of the 1/2" hex
compression nuts that hold the bypass line in place.
Loosen the compression nuts using a 1/2" wrench.
b. Remove the bypass tube. Then, remove the bypass
orifice from the tube.
c. Slip the new orifice into the bypass tube.
d. Replace the tube onto its fittings on the solenoid valve.
While holding the tube in place, slide the compression
nuts back into place and engage the threads. Tighten
the nut to a snug fit with your fingers.
e. Gently tighten the nuts one complete turn with a wrench.
DO NOT OVERTIGHTEN THE COMPRESSION NUTS.
f.Replace the gas train and venturi by following Steps a-
Replacing the Main Orifice, above, in reverse order.
d in
WARNING
After completing these procedures, perform a gas
leak test before operating the oven.
ENGLISH
Ignition
sensor
wire
Venturi
mounting
plate
Main orifice
holder (attached
to gas train)
13
SECTION 2 - INSTALLATION
E. Checking the Gas Supply (Inlet) Pressure
1. Remove the supply (inlet) pressure cap screw from the
multifunction gas valve. Attach a manometer to the stud.
2. Depress the machinery compartment safety switch to
ENGLISH
allow the oven to operate.
3. Open the main gas supply valve. Switch the circuit breaker/
fused disconnect to the ON ("I") position.
4. Start the oven and adjust the temperature controller to the
maximum setting (288°C).
5. Measure the supply (inlet) pressure.
6. Switch the oven off. Close the main gas supply valve, and
switch the circuit breaker/fused disconnect to the OFF ("O")
position. Remove the manometer, and replace the cap
screw onto the multifunction gas valve.
7. Compare the measured supply (inlet) pressure to the
nominal pressures shown in the Gas Orifices and PressureSpecifications table.
If the supply pressure is lower or higher than the nominal
pressure, the reason should be investigated and the gas
supplier contacted.
For natural gas ovens, if the measured supply pressure is lower
than 17mbar, or higher than 25mbar, contact the gas supplier.
DO NOT OPERATE THE OVEN or adjust the oven controls.
F.Adjusting the Orifice (Manifold) Pressure and Heat Input
To use the orifice pressure method, you must know the specific
gas type and quality used. If using the orifice pressure method,
you should double-check the input using the volumetric method.
To use the volumetric method, you must know the heat value
(HuB) of the gas used. This information is available from your
gas supplier.
During these measurements, do not operate any other
appliances that use the same gas meter as the oven.
1. Orifice (Manifold) Pressure Method
a. Check that the main gas supply valve and the circuit
breaker/fused disconnect are in the OFF ("O") position.
b. Remove the regulated (manifold) pressure cap screw
from the multifunction gas valve. Attach a manometer
to the stud.
c. Remove the cap screw from the pressure adjustment
screw (governor) on the multifunction gas valve.
d. Depress the machinery compartment safety switch to
allow the oven to operate.
e. Open the main gas supply valve. Switch the circuit
breaker/fused disconnect to the ON ("I") position.
f.Start the oven and adjust the temperature controller to
the maximum setting (288°C).
g. Adjust the pressure adjustment screw as necessary
to match the correct pressure for the oven's specific
gas type. Refer to the Gas Orifices and PressureSpecifications table. Turning the adjustment screw
clockwise increases the flow, while turning it
counterclockwise reduces the flow.
h. Switch the oven off. Close the main gas supply valve,
and switch the circuit breaker/fused disconnect to the
OFF ("O") position. Remove the manometer, and
replace the cap screws onto the multifunction gas
valve.
2. Volumetric Method
a. Determine the time of 0.1m
3
(100 liters) of gas usage
as follows.
Consumption (m
3
/hr.) =
NB (Rated input in kW)
HuB (Heat [Calorific] value
of gas in kW/m3)
Time (in minutes) of
0.1m3 of gas usage
=
6
Consumption
b. Check that the main gas supply valve and the circuit
breaker/fused disconnect are in the OFF ("O") position.
c. Remove the cap screw from the pressure adjustment
screw (governor) on the multifunction gas valve.
d. Depress the machinery compartment safety switch to
allow the oven to operate.
e. Open the main gas supply valve. Switch the circuit
breaker/fused disconnect to the ON ("I") position.
f.Start the oven and adjust the temperature controller to
the maximum setting (288°C).
g. Adjust the pressure adjustment screw as necessary
to match the calculated volume using the time (in
minutes) of 0.1m
3
of gas usage. Turning the
adjustment screw clockwise increases the flow, while
turning it counterclockwise reduces the flow.
h. Record the reading obtained from the gas meter and
calculate the obtained gas flow. Compare this value
to the information in the Gas Orifices and PressureSpecifications table.
i.Switch the oven off. Close the main gas supply valve,
and switch the circuit breaker/fused disconnect to the
OFF ("O") position. Replace the cap screw onto the
multifunction gas valve.
14
SECTION 3 - OPERATION
I.LOCATION AND DESCRIPTION OF CONTROLS
Fig. 3-1 - Control Panel
E.
Conveyor Speed
") controller(s)
("
ENGLISH
D.
"RESET"
) switch
(
GAS OVENS ONLY
A.
"BLOWER" Switch: Turns the blowers and
A.
"BLOWER"
")
("
switch
E.
cooling fans on and off. The HEAT Switch has
no effect unless the BLOWER Switch is in the
ON position.
B.
"HEAT"
("
switch
")
C.
"CONVEYOR"
("
switch
")
Conveyor Speed Controller: Adjusts and displays the bake time. Single-belt ovens have one
controller. Split belt ovens have one controller
for each conveyor belt, labeled "FRONT" and
F.
Digital Temperature
") controller
("
"BACK."
B.
"HEAT" Switch: Allows the burner or heating
elements, as appropriate for the oven model, to
activate. Activation is determined by the settings on the Digital Temperature Controller.
F.
Digital Temperature Controller: Continuously
monitors the oven temperature. Settings on the
Digital Temperture Controller control the activation of the burner or heating elements.
C.
"CONVEYOR" Switch: Turns the conveyor drive
motor on and off.
NOT SHOWN:
D.
"RESET" Switch: Gas ovens only. Illuminates
if the gas burner does not light. The switch can
be pressed repeatedly to attempt to light the
burner. If the burner does not light within 15
minutes, the "RESET" (
) switch is locked out.
G. Machinery Compartment Access Panel Safety Switch:
Disconnects electrical power to the controls and the blowers when the machinery compartment access panel is
opened. The panel should only be opened by authorized
service personnel.
15
SECTION 3 - OPERATION
II. NORMAL OPERATION - STEP-BY-STEP
A. DAILY STARTUP PROCEDURE
1. Check that the circuit breaker/fused disconnect is in the on
ENGLISH
position. Check that the window is closed.
2. Turn the "BLOWER" ()
switch to the ON ("I")
position.
3. Turn the "CONVEYOR"
) switch to the ON
(
("I") position.
4. If necessary, adjust the
conveyor speed setting
by pressing the
pushbuttons on the conveyor speed controller to
change the displayed
bake time.
Some ovens may be
equipped with a
thumbwheel speed controller. For these ovens,
turn the three
thumbwheels to change
the displayed bake time.
5. Adjust the temperature
controller to a desired set
temperature, if necessary.
Press the Set Point
and Unlock keys at
the same time. Wait
for the "SET PT" light
to turn on.
Press the Up Arrow
and Down Arrow
Keys as necessary
to adjust the setpoint.
or
+
or
mins secs
thumbwheels
or
wait
for
7.(Gas ovens only) If the "RESET" (
nates, the gas burner did
not light. Press the "RESET" (
edly if necessary) to attempt to light the burner.
NOTE: If the burner does not light within 15 minutes, the
oven enters a safety lockout mode that disables the "RESET" (
"BLOWER" (
"OFF" ("O") position.
Then, repeat the Daily Startup procedure.
7. Wait for the oven to heat to the setpoint temperature. Higher
setpoint temperatures will require a longer wait. The oven
can reach a temperature of 232°C in approximately 5
minutes.
8. (Optional) Press the Temperature ( ) key to show
the Actual Temperature
in the display, and wait
for the "ACTUAL TEMP"
light to turn on. This allows you to monitor the
oven temperature as it
rises to the setpoint.
9. Allow the oven to preheat for 10 minutes after it has reached
the set point temperature.
B. DAILY SHUTDOWN PROCEDURE
1. Turn the "HEAT" (
"BLOWER" (
ches to the "OFF" ("O")
position. Note that the
blowers will remain in operation until the oven has
cooled to below 93°C.
2. Make certain that there
are no products left on
the conveyor inside the
oven. Turn the "CONVEYOR" (
the "OFF" ("O") position.
) switch illumi-
) switch (repeat-
) switch. If this occurs, turn the "HEAT" (),
), and "CONVEYOR" () switches to the
Wait for AT LEAST FIVE MINUTES.
wait
for
) and
) swit-
+
) switch to
6. Turn the "HEAT" ()
switch to the "ON" ("I")
position, and wait for the
"HEAT ON" light to turn
on.
wait
for
3. Open the window to allow the oven to cool faster.
4. After the oven has cooled and the blowers have turned off,
switch the circuit breaker/fused disconnect to the off position.
CAUTION
In case of power failure, turn all switches to the OFF ("O")
position, open the oven window, and remove the product.
After the power has been restored, perform the normal
startup procedure.
On gas ovens, the burner will not operate and gas will not
flow through the burner without electric power. No
attempt should be made to operate the oven during a
power failure.
16
III. QUICK REFERENCE: DIGITAL TEMPERATURE CONTROLLER
SECTION 3 - OPERATION
"SP LOCK" Light
Lights when the set
point is locked out
from changes. This
setting can only be
changed by service
personnel.
OVERTEMP Light
Lights when the oven
temperature is greater
than 343°C. Refer to
Quick Reference:
Troubleshooting in
this section.
Temperature Key
Press this key once to
view the Actual Temperature in the Display.
Display
Shows the Set Point or
the Actual Temperature in degrees Fahrenheit (F) or Celsius
(C).
"HEAT ON" Light
Lights when the
burner or heating elements, as appropriate
for the oven model,
are in operation.
ENGLISH
"SET PT" (setpoint)
Light
Lights when the set
point is shown in the
display.
"ACTUAL TEMP"
Light
Lights when the
Actual Temperature is shown in
the display.
Service Key
For use by service personnel
only.
Unlock Key
Press this key together
with the Set Point Key
to allow the Set Point
to be changed.
Changes can only be
made for 60 seconds.
Up Arrow and Down Arrow
Keys
Press these keys to adjust
the Set Point up or down. If
the Set Point will not
change, refer to
Key and Unlock Key in this
section.
Set Point
17
Set Point Key
Press this key together
with the Unlock Key to
allow the Set Point to
be changed.
Changes can only be
made for 60 seconds.
SECTION 3 - OPERATION
IV. QUICK REFERENCE: TROUBLESHOOTING
SYMPTOMPROBLEMSOLUTION
ENGLISH
light is lit, food product is
undercooked
Oven will not
turn on at all
"RESET" (
illuminated, oven will not
(gas ovens only)
appears in display,
oven is not heating
heat
) switch is
The oven temperature exceeded 343°C, and the
burner or heating elements
were automatically shut
down.
Electrical power may not be
reaching the oven, or the
controls may be set incorrectly.
The gas burner did not light
within 90 seconds of turning the "HEAT" (
to the ON ("I") position.
The oven did not reach
93°C within 15 minutes of
startup, and the oven has
stopped heating.
) Switch
Follow the procedures under
this section to shut down the oven. Contact your Middleby
Marshall Authorized Service Agent to determine and correct the
cause of the condition to prevent damage to the oven.
Check that the circuit breaker/fused disconnect is turned on.
Check that the "BLOWER"
position. The burner cannot engage until the blowers are in
operation.
Press the "RESET" (
attempt to light the burner.
If the burner does not light within 15 minutes, the oven will enter
a safety lockout mode that disables the "RESET" (
If this occurs, turn the "HEAT" (
"CONVEYOR" (
for AT LEAST FIVE MINUTES before restarting the oven. Then,
repeat the Daily Startup procedure.
Turn the "HEAT" (
)switches to the "OFF" ("O") position.
(
Wait for AT LEAST FIVE MINUTES before restarting the oven.
Repeat the Daily Startup procedure.
)switches to the "OFF" ("O") position. Wait
), "BLOWER" (), and "CONVEYOR"
Daily Shutdown Procedures in
() Switch is in the ON ("I")
) switch (repeatedly if necessary) to
) switch.
), "BLOWER" (), and
Oven will not heat
Oven is operating, but
little or no air is blowing
from air fingers
Conveyor moves with a
jerky motion, or will not
move at all
Food products are
overcooked or
undercooked.
Controls may be set incorrectly.
Air fingers may have been
reassembled incorrectly
after cleaning.
Conveyor may be jammed
on an object in the oven, or
conveyor belt or drive chain
tension may be incorrect.
Controls may be set incorrectly.
Check that the Set Point is correctly set.
Check that both the "BLOWER"
are in the ON ("I") position.
If the oven still will not heat,turn the "HEAT" (
(), and "CONVEYOR" ()switches to the "OFF" ("O")
position.
Wait for AT LEAST FIVE MINUTES before restarting the oven.
Repeat the Daily Startup procedure. Check that the Set Point
is above 93°C.
Turn the oven off, and allow it to cool. Disconnect electrical
power to the oven.
Refer to Section 4,
bling the air fingers.
Turn the oven off, and allow it to cool. Disconnect electrical
power to the oven.
Check if the conveyor is blocked by an object inside the oven.
Refer to Section 4,
the conveyor and drive chain tension.
Check that the set temperature and bake time settings are
correct.
Maintenance, for instructions on reassem-
Maintenance, for instructions on checking
() and "HEAT" () Switches
), "BLOWER"
IF THESE STEPS FAIL TO RESOLVE THE PROBLEM, CONTACT YOUR LOCAL MIDDLEBY MARSHALL
AUTHORIZED SERVICE AGENT. A SERVICE AGENCY DIRECTORY IS SUPPLIED WITH YOUR OVEN.
18
SECTION 4 - MAINTENANCE
WARNING
Before ANY cleaning or servicing of the oven, perform the following procedure:
1. Switch off the oven and allow it to cool. Do NOT service the oven while it is warm.
2. Turn off the electric supply circuit breaker(s)
3. If it is necessary to move a gas oven for cleaning or servicing, disconnect the gas supply connection before moving the oven.
and disconnect the electric supply to the oven.
When all cleaning and servicing is complete:
1. If the oven was moved for servicing, return the oven to its
original location. Adjust the legs so that they are seated
properly on the floor.
2. For gas ovens, reconnect the gas supply.
3. Reconnect the electrical supply.
4. For gas ovens, turn on the full-flow gas safety valve. Test
the gas line connections for leaks using approved leak
test substances or thick soap suds.
5. Turn on the electric supply circuit breaker(s).
6. Perform the normal startup procedure.
WARNING
Possibility of injury from moving parts and electrical shock exists in this oven. Switch off and lockout/tagout the electric supply
BEFORE beginning to disassemble, clean, or service any oven. Never disassemble or clean an oven with the BLOWER (
switch or any other circuit of the oven switched on.
CAUTION
NEVER use a water hose, water jet, or pressurized steam-cleaning equipment when cleaning this oven. DO NOT use
excessive amounts of water, to avoid saturating the oven insulation. DO NOT use a caustic oven cleaner, which can damage
the aluminized bake chamber surfaces.
NOTE
ANY replacement parts that require access to the interior of the oven may ONLY be replaced by a Middleby Marshall Authorized
Service Agent. It is also strongly recommended that the 3-Month Maintenance and 6-Month Maintenance procedures in this
section be performed ONLY by a Middleby Marshall Authorized Service Agent.
I. MAINTENANCE - DAILY
A. Check that the oven is cool and the power is disconnected,
as described in the warning at the beginning of this Section.
B. Clean the outside of the oven with a soft cloth and mild
detergent.
C. Clean ALL of the cooling fan grills and vent openings with a
stiff nylon brush.
D. Check that ALL cooling fans are operating properly.
CAUTION
If a cooling fan is not operating correctly, it must be replaced
IMMEDIATELY. Operating the oven without adequate
cooling can seriously damage the oven's internal components.
E. Clean the conveyor belts with a stiff nylon brush. This is
more easily accomplished by allowing the conveyor to run
while you stand at the exit end of the conveyor. Then, brush
the crumbs off the conveyor as it moves.
F. Remove and clean the crumb trays. Be sure to replace the
trays in the same positions from which they were removed,
because they are NOT identical. Refer to Figure 4-1.
G. Clean the window in place.
Lower oven
Figure 4-1 - Crumb trays
Upper oven
(drive end)
Upper oven
(idler end)
ENGLISH
)
19
SECTION 4 - MAINTENANCE
II. MAINTENANCE - MONTHLY
A. Check that the oven is cool and the power is disconnected,
as described in the warning at the beginning of this Section.
B. Remove the crumb trays, drive motor shroud, and conveyor
ENGLISH
extension covers from the oven.
C. Lift the drive end of the conveyor slightly, and push it forward
into the oven. This removes the tension from the drive
chain. Then, remove the drive chain from the conveyor
sprocket.
NOTE
Split belt conveyors can only be removed from the end of
the oven
with the drive motor.
Single-belt conveyor assemblies may be removed from
either end of the oven. If it is to be removed from the end
of the oven
without the drive motor, the drive sprocket
assembly must be removed.
To remove the drive sprocket (if necessary), loosen the set
screw on the conveyor collar as shown in Figure 4-2. Then,
pull the sprocket assembly straight out.
D. Slide the conveyor out of the oven, folding it as it is removed.
See Figure 4-3.
E. Remove the end plugs from the oven.
F. Slide the air fingers and blank plates out of the oven, as
shown in Figure 4-4. AS EACH FINGER OR PLATE IS
REMOVED, WRITE A "LOCATION CODE" ON IT WITH A
MARKER to make sure that it can be reinstalled correctly.
Example of markings:
(Top Row)T1T2T3T4T5T6
(Bottom Row)B1B2B3B4B5B6
G. Disassemble the air fingers as shown in Figure 4-4. AS
EACH FINGER IS DISASSEMBLED, WRITE THE "LOCATION CODE" FOR THE FINGER ON ALL THREE OF ITS
PIECES. This will help you in correctly reassembling the
air fingers.
CAUTION
Incorrect reassembly of the air fingers will change the
baking properties of the oven.
H. Clean the air finger components and the interior of the
baking chamber using a vacuum cleaner and a damp cloth.
Refer to the boxed warnings at the beginning of this Section
for cleaning precautions.
I.Reassemble the air fingers. Then, replace them in the
oven, using the "location code" as a guide.
J. Replace the end plugs on the oven.
K. Reassemble the conveyor into the oven. If the drive sprocket
was removed when installing the conveyor, replace it at this
time.
L. Reattach the drive chain.
M. Check the tension of the conveyor belt as shown in Figure
4-5. The belt should lift between 75-100mm. DO NOT
OVERTIGHTEN THE CONVEYOR BELT. If necessary, the
belt tension can be adjusted by turning the conveyor adjustment screws, located at the idler (right) end of the conveyor.
N. Replace the conveyor extension covers, drive motor shroud,
and crumb trays.
Figure 4-2 - Removing the Conveyor Drive Sprocket
Loosen conveyor collar
set screw, then pull
sprocket straight out
Figure 4-3 - Removing the Conveyor
Figure 4-4 - Removing Air Fingers and Plates
Manifold
Inner plate
Outer plate
Figure 4-5 - Checking the conveyor tension
75-100mm
vertical
deflection
Conveyor
tension
adjustment
screws (idler
end only)
20
III. MAINTENANCE - EVERY 3 MONTHS
A. Check that the oven is cool and the power is disconnected,
as described in the warning at the beginning of this Section.
B. Vacuum both of the blower motors, and their surrounding
compartments, using a shop vacuum.
C. Tighten all electrical control terminal screws.
D. Split Belt Disassembly and Cleaning
For split belt ovens ONLY, disassemble, clean and lubricate the
conveyor shaft components as described below.
1. Remove the motor shroud, conveyor extensions, and conveyor as described in Part II,
2. Remove the master links from each conveyor belt. Then,
roll the belts up along the length of the conveyor to remove
them from the frame.
3. Remove the two conveyor adjustment screws from the idler
end of the conveyor frame, as shown in Figure 4-6.
4. Remove the idler shaft assembly from the conveyor.
5. Pull apart the two sections of the idler shaft. Clean the
shafts thoroughly using a rag. Then, lubricate both the
extended shaft and the interior of the hollow shaft using an
FDA-approved light food-grade lubricant.
CAUTION
DO NOT lubricate the shafts using WD40 or a similar
product. This can cause the shafts to wear rapidly.
6. Before reassembling the shafts into the conveyor frame,
check that they are oriented properly. Remember that
unequal-width split belt ovens should ALWAYS have the
narrower belt at the front of the oven.
7. Reassemble the idler shaft into the conveyor.
that the bronze washer is in place between the two sections
of the shaft. See Figure 4-8.
8. Replace the conveyor adjustment screws as shown in
Figure 4-6. To allow the conveyor belt to be reinstalled later,
do not tighten the screws at this time.
9. Loosen the set screw on both of the conveyor drive sprockets. Then, remove the sprockets from the shaft.
10. Loosen the locking collar set screw, as shown in Figure 4-7.
11. Push the drive shaft to the right, then lift it free of the conveyor
frame. Then, disassemble and lubricate the two sections
of the drive shaft as described in Step 5.
12. Before reassembling the shafts into the conveyor frame,
check that they are oriented properly. Remember that
unequal-width split belt ovens should ALWAYS have the
narrower belt at the front of the oven.
13. Reassemble the drive shaft into the conveyor.
the nylon spacer is in place, as shown in Figure 4-8. Also,
check that the bronze washer is in place between the two
sections of the shaft.
14. Replace the drive sprockets. Reassemble the belts and
master links onto the conveyor. Check that the smooth side
of the conveyor belt faces UP, and that the belt and master
links are oriented as shown in Figure 4-9.
15. Reassemble the conveyor, motor shroud and conveyor
extensions onto the oven.
16. Check the tension of the conveyor belt as shown in Figure 4-5. The
belt should lift between 75-100mm. If necessary, adjust the belt
tension by turning the conveyor adjustment screws.
Monthly Maintenance.
Make sure
Check that
21
SECTION 4 - MAINTENANCE
Figure 4-6 - Split Belt Idler Shaft
Conveyor
adjustment
screw
Figure 4-7 - Split Belt Drive Shaft
Locking collar
Figure 4-8 - Washer and Spacer
Bronze washer on
BOTH idler and
drive shafts
Nylon spacer
on drive shaft
ONLY
Figure 4-9 - Conveyor and Master Link Orientation
Direction
of travel
CORRECT
master link
position
Incorrect
master link
position
ENGLISH
SECTION 4 - MAINTENANCE
IV. MAINTENANCE - EVERY 6 MONTHS
A. Check that the oven is cool and the power is disconnected,
as described in the warning at the beginning of this Section.
B. Check for excessive wear on the conveyor drive motor
ENGLISH
brushes. The brushes should be replaced if they have worn
to less than 1/4" (6.4mm) in length. Be sure to replace the
brushes in exactly the same position.
C. For gas ovens, clean and inspect the burner nozzle and
electrode assembly.
D. Check (and clean, if necessary) the oven venting system.
E. Check the conveyor drive shaft bushings and spacers.
Replace the components if they are worn.
V. KEY SPARE PARTS KIT - Available separately. See Figure 4-10.
ItemPart No.Description
136939Kit, Digital Temperature Controller
227384-0008Motor, Conveyor Drive
322450-0052Brushes, Drive Motor
427170-0263Assembly, Pickup, Conveyor Drive
537337Kit, Conveyor Speed Controller
633984Kit, Thermocouple
727392-0002Fan, Cooling
835625Kit, Air Switch
9a27381-0023Motor, Blower, PS360U and PS360L Gas and
Electric Ovens, 1/3 HP
9b31432Motor, Blower, PS360WB-U and PS360WB-L
Gas Ovens, 1 HP
GAS OVENS ONLY:
1027170-0287Assembly, Burner Blower and Motor
1135825Kit, Ignition Module
12a37770Kit, High Flame Solenoid Valve, 220V
12b37851Kit, High Flame Solenoid Valve, 120V (for