Middleby Marshall PS520G Operation manual

©2006 Middleby Marshall Inc.
MiddlebyMiddleby
MiddlebyMiddleby
Middleby
MarshallMarshall
MarshallMarshall
Marshall
AMIDDLEBYCOMPANY
PS520-Series Gas Ovens: English
October 17, 2006
owner's
operating
& installation
manual
PS520-Series OVENS
Model PS520G
PS520 (Triple)
PS520 (Double)
Part No. 59223
Price $30.00
P: 10/06
®
PS520 (Single)

ii
WARNING
FOR YOUR SAFETY, DO NOT STORE OR USE
GASOLINE OR OTHER FLAMMABLE VAPORS AND
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, operation, and maintenance
instructions thoroughly before installing or servicing this
equipment.
NOTICE
The warranty is NOT VALID unless the oven is installed, started, and
demonstrated under the supervision of a factory-authorized installer.
NOTICE
Contact your authorized Service Agency to perform maintenance and
repairs. A 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.
KEEP THIS MANUAL IN A VISIBLE LOCATION NEAR THE OVEN
FOR FUTURE REFERENCE.
NOTICE:
This Owner's Operating and Installation Manual should be given to the user. The operator of the oven should
be familiar with the functions and operation of the oven.
This manual must be kept in a prominent, easily reachable location near the oven.
Ovens are shipped from the factory configured for use with natural gas. If permitted by local, national and
international codes, at the time of installation the oven may be converted to propane gas operation. This
conversion requires the use of at Gas Conversion Kit that is supplied with the oven. For CE-approved ovens,
the conversion is described in the Installation section of this Manual. For domestic and standard export ovens,
instructions are included in the 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.

iii
MIDDLEBY MARSHALL INC.
OVEN LIMITED WARRANTY
(Non U.S.A.)
The Seller warrants equipment manufactured by it to be free from
defects in material and workmanship for which it is responsible. The
Seller’s obligation under this warranty shall be limited to replacing or
repairing, at Seller’s option, without charge, F.O.B. Seller’s factory,
any part found to be defective and any labor and material expense
incurred by Seller in repairing or replacing such part. Such warranty
is limited to a period of one year from date of original installation or
15 months from date of shipment from Seller’s factory, whichever is
earlier, provided that terms of payment have been fully met. All labor
shall be performed during regular working hours. Overtime premium
will be charged to the Buyer.
This warranty is not valid unless equipment is installed, started,
and demonstrated under the supervision of a factory-autho-
rized installer.
Normal maintenance functions, including lubrication, adjustment of
airflow, thermostats, door mechanisms, microswitches, burners
and pilot burners, and replacement of light bulbs, fuses and indicat-
ing lights, are not covered by warranty.
Any repairs or replacements of defective parts shall be performed by
Seller’s authorized service personnel. Seller shall not be respon-
sible for any costs incurred if the work is performed by other than
Seller’s authorized service personnel.
When returning any part under warranty, the part must be intact and
complete, without evidence of misuse or abuse, freight prepaid.
Seller shall not be liable for consequential damages of any kind
which occur during the course of installation of equipment, or which
result from the use or misuse by Buyer, its employees or others of
the equipment supplied hereunder, and Buyer’s sole and exclusive
remedy against Seller for any breach of the foregoing warranty or
otherwise shall be for the repair or replacement of the equipment or
parts thereof affected by such breach.
The foregoing warranty shall be valid and binding upon Seller if and
only if Buyer loads, operates and maintains the equipment supplied
hereunder in accordance with the instruction manual provided to
Buyer. Seller does not guarantee the process of manufacture by
Buyer or the quality of product to be produced by the equipment
supplied hereunder and Seller shall not be liable for any prospective
or lost profits of Buyer.
THE FOREGOING WARRANTY IS EXCLUSIVE AND IN LIEU OF
ALL OTHER EXPRESS AND IMPLIED WARRANTIES WHATSO-
EVER. SPECIFICALLY THERE ARE NO IMPLIED WARRANTIES
OF MERCHANTABILITY OR OF FITNESS FOR A PARTICULAR
PURPOSE.
The foregoing shall be Seller’s sole and exclusive obligation and
Buyer’s sole and exclusive remedy for any action, whether in breach
of contract or negligence. In no event shall seller be liable for a sum
in excess of the purchase price of the item.
Model No.
Modéle No.
Serial No.
Serié No.
Installation Date
Date d'installation
MIDDLEBY MARSHALL
NOQUIBBLE LIMITED WARRANTY
(U.S.A. ONLY)
MIDDLEBY MARSHALL, HEREINAFTER REFERRED TO AS
“THE SELLER”, WARRANTS EQUIPMENT MANUFACTURED
BY IT TO BE FREE FROM DEFECTS IN MATERIAL AND
WORKMANSHIP FOR WHICH IT IS RESPONSIBLE. THE
SELLER’S OBLIGATION UNDER THIS WARRANTY SHALL
BE LIMITED TO REPLACING OR REPAIRING, AT SELLER’S
OPTION, WITHOUT CHARGE, ANY PART FOUND TO BE
DEFECTIVE AND ANY LABOR AND MATERIAL EXPENSE
INCURRED BY SELLER IN REPAIRING OR REPLACING
SUCH PART. SUCH WARRANTY SHALL BE LIMITED TO
THE ORIGINAL PURCHASER ONLY AND SHALL BE EFFEC-
TIVE FOR A PERIOD OF ONEYEAR FROM DATE OF ORIGI-
NAL INSTALLATION, OR 18 MONTHS FROM DATE OF PUR-
CHASE, WHICHEVER IS EARLIER, PROVIDED THATTERMS
OF PAYMENT HAVE BEEN FULLY MET.
This warranty is valid only if the equipment is installed, started,
and demonstrated under the supervision of a factory-autho-
rized installer.
Normal maintenance functions, including lubrication, clean-
ing, or customer abuse, are not covered by this no quibble
warranty .
Seller shall be responsible only for repairs or replacements
of defective parts performed by Seller’s authorized service
personnel. Authorized service agencies are located in prin-
cipal cities throughout the contiguous United States, Alaska,
and Hawaii. This warranty is valid in the 50 United States
and is void elsewhere unless the product is purchased
through Middleby International with warranty included.
The foregoing warranty is exclusive and in lieu of all other
warranties, expressed or implied. There are no implied
warranties of merchantability or of fitness for a particu-
lar purpose.
The foregoing shall be Seller’s sole and exclusive obligation
and Buyer’s sole and exclusive remedy for any action, in-
cluding breach of contract or negligence. In no event shall
Seller be liable for a sum in excess of the purchase price of
the item. Seller shall not be liable for any prospective or lost
profits of Buyer.
This warranty is effective on Middleby Marshall equip-
ment sold on, or after, February 15, 1995.
© 2003 - Middleby Marshall, A Middleby Company.
The Middleby Marshall logo is a registered trademark of Middleby Marshall, A Middleby Company.
Middleby Marshall Inc. • 1400 Toastmaster Drive • Elgin, Illinois 60120-9272 U.S.A.• [phone] • FAX: [phone]

iv
NOTE
Wiring Diagrams are in Section 6 of this Manual.
The diagram for each oven is also on the lower
inner surface of its Control Console.
TABLE OF CONTENTS
Page
SECTION 1
I. MODEL IDENTIFICATION .............................................. 1
SERIES PS520 GAS SPECIFICATIONS ............................ 2
II. COMPONENT FUNCTION ............................................. 4
A. Conveyor Motor and Conveyor Belt ........................ 4
B. Blower Fan ................................................................. 4
C. Gas Burner ................................................................ 4
D. Cooling Fan ................................................................ 4
E. Air Fingers and Blank Plates - See Figure 1-9 ........ 4
SECTION 2
I. UNLOADING ................................................................... 8
PARTS LIST FOR SERIES PS520 GAS OVEN
INSTALLATION KIT .................................................... 8
UTILITY ROUGH-IN DIMENSIONS AND POSITIONING
FOR PS520-SERIES OVENS .................................... 13
CIRCUIT BREAKER ..................................................... 13
ELECTRICAL SPECIFICATIONS ................................. 13
ELECTRICAL RATING ................................................. 13
SUPPLY WIRE .............................................................. 13
SUGGESTED ................................................................ 13
II. VENTILATION GUIDELINES ........................................ 13
III. ELECTRICAL CONNECTION INFORMATION FOR
PS520-SERIES OVENS. ........................................... 14
IV. ELECTRIC SUPPLY FOR GAS HEATED OVENS ..... 14
V. GAS SUPPLY .............................................................. 15
SECTION 3 INSTALLATION
I. CONTROL FUNCTIONS ................................................ 17
II. COMPONENT INFORMATION AND LOCATION ......... 18
A. Door Safety Switch .................................................. 18
B. Blower Switch .......................................................... 18
C. Heat Switch .............................................................. 18
D. Temperature Controller .......................................... 18
E. Conveyor ................................................................. 19
MEASURING CONVEYOR SPEED. ............................. 19
TABLE OF CONTENTS
(Continued)
Page
III. STEP-BY-STEP OPERATION ....................................... 20
A. Startup Procedures ................................................. 20
Daily Startup ................................................................. 20
Power Failure ............................................................... 20
B. Shutdown Procedure ............................................... 20
IV. NORMAL OPERATION - STEP-BY-STEP ................... 22
A.Daily Startup Procedure ........................................... 22
B. Daily Shutdown Procedure ...................................... 22
V. QUICK REFERENCE: TROUBLESHOOTING ............ 24
SECTION 4 MAINTENANCE
I. MAINTENANCE - DAILY ............................................ 26
A. Exterior ..................................................................... 26
B. Cooling Fan ............................................................... 26
C. Conveyor Belt .......................................................... 26
D. Crumb Pans ............................................................. 26
II. MAINTENANCE - MONTHLY ....................................... 27
A. Removing Conveyor From Oven For Cleaning ..... 27
B. Air Fingers Disassembly For Cleaning .................. 29
C. Reassembly of Air Fingers ..................................... 30
D. Reinstall End Plugs ................................................. 33
E. Conveyor Reassembly Into Oven .......................... 34
F. Checking Conveyor Belt Tension ........................... 34
G. Conveyor Belt Link Removal ................................. 35
H. Attaching Drive Chain ............................................. 36
III. MAINTENANCE - EVERY 3 MONTHS ......................... 37
A. Electrical Terminals ................................................ 37
B. Ventilation ................................................................ 37
IV. MAINTENANCE - EVERY 6 MONTHS ........................ 37
PS520-SERIES GAS OVEN KEY SPARE
PARTS ....................................................................... 38
KEY SPARE PARTS KIT ............................................... 38
SECTION 5 TROUBLESHOOTING
Troubleshooting Charts ...................................................... 39
SECTION 6 ELECTRICAL SCHEMATICS
Wiring Diagram, G208-240V 50/60 GO, PS520 ............... 41

SECTION 1
DESCRIPTION
1
I. MODEL IDENTIFICATION
The Middleby Marshall PS520-Series may be used either
as a single oven or stacked for use as double or triple
ovens.
A single PS520-Series Oven (Figure 1-1) is mounted on a
base pad with legs. A double oven (Figure 1-2) consists of
two, stacked, single ovens. A triple oven (Figure 1-3)
consists of three stacked single ovens. The lower oven is
mounted on a base pad with stacking pins.
On a double or triple oven, the ovens operate indepen-
dently. All ovens use identical controls and components.
One oven can be cleaned or serviced, while the others are
operating.
SECTION 1
DESCRIPTION
Figure 1-1. Single PS520 Oven
Figure 1-2. Double PS520 Oven
Figure 1-3. Triple PS520 Oven

2
SECTION 1
DESCRIPTION
PS520 SERIES OVEN SPECIFICATIONS
Conveyor Belt Width 18.00″(457mm)
Heating Zone Length 20.00″(5098mm)
Baking Area Square Feet 2.5 sq. ft. (0.23 sq. m.)
Overall Dimension – Standard Single Oven w/Legs 42.00″(1067mm) L ×
35.21″(894mm) W ×
21.10″(536mm) H ×
Overall Dimension – Double Oven 42.00″(1067mm) L ×
35.21″(894mm) W ×
36.64″(931mm) H x
Overall Dimension – Triple Oven 42.00″(1067mm) L x
35.21″(894mm) W ×
48.19″(1224mm) H ×
Weight of Single Oven 250 lb (93.3kg)
Shipping Weight 325 lb (121.3kg)
Shipping Cube 22.1 ft3(0.62 m3)
Operating Range 8.3 kW/hr
BTU's – Natural or Propane Gas 40,000 BTU/HR
Gas Input – Natural or Propane Gas 1/2″NPT
Maximum Operating Temperature 600°F (316°C)
Warm-up Time 20 min.
Belt Speed Limits 1-10 minutes
SERIES PS520 ELECTRICAL SPECIFICATIONS
Main Blower & Control Circuit Phase Frequency Amperage Poles Wires
Elements Voltage Voltage Draw
208-240V 208-240V 1 Ph 50/60 Hz 1.5 Amp 2 Pole 3 Wire
(2 hot, 1 grd)
GAS ORIFICE AND PRESSURE SPECIFICATIONS (PER OVEN CAVITY) - CE OVENS
Supply (Inlet) Pressure
IT,PT,ES,SE,
Main UK,CH,IT,AT, SE,CH,AT,DK, BE,IE,IT,PT, Orifice Rated
Gas Orifice DK,FI DE BE,FR FI,DE,NL ES,UK (Manifold) Heat
Type dia. I
2H
I
2E
I
2E+
I
3B/P
I
3+
Pressure Input
G20 2.3749 20 20 20 -- -- 11.21 22.36
mm mbar mbar mbar mbar kW-hr.
G25 2.3749 -- -- -- -- -- 16.19 22.36
mm mbar kW-hr.
G30 1.3970 -- -- -- 29 or 50 28-30, 37 26.2 22.59
mm mbar or 50 mbar mbar kW-hr.
GAS ORIFICE AND PRESSURE SPECIFICATIONS (PER OVEN CAVITY) - DOMESTIC AND STANDARD EXPORT OVENS
Orifice (Manifold)
Gas Type Main Orifice I.D. Bypass Orifice I.D. Supply (Inlet) Pressure Pressure
Natural 0.082” (2.08mm, #45 drill) 0.073” (2.0574mm, #49 drill) 6-12” W.C. (14.9-29.9mbar) * 3.5” W.C. (8.72mbar)
Propane 0.057” (1.45mm, #46 drill) 0.052” (1.85mm, #55 drill) 11-14” W.C. (27.4-34.9mbar) * 7” W.C. (17.44mbar)
* The gas supply pressures and orifice sizes shown are for ovens installed in North America. The required gas supply pressures and orifice
sizes of ovens installed in other locations are dependent on the local gas type and on all applicable local codes.
NOTE
Wiring Diagrams are contained in Section 6 of this Manual
and are also located inside the oven at the
bottom of the Control Panel.
Additional electrical information is provided on the oven's serial plate.
This Manual Must Be Kept For Future Reference.

SECTION 1
DESCRIPTION
3
II. COMPONENT FUNCTION (Figure 1-4)
Figure 1-4. PS520-Series Oven Components Locations

4
SECTION 1
DESCRIPTION
II. COMPONENT FUNCTION
A. Conveyor Motor and Conveyor Belt
The conveyor belt is driven by a variable-speed electric
motor (Figure 1-5) operating through a gear reducer. The
motor speed is controlled by a digital control. The stain-
less-steel wire belt can travel in either direction at variable
rates ranging from 3 minutes to 30 minutes; this is the time
that a product can take to pass through the oven.
B. Blower Fan
The blower fans are located at the rear of the oven. These
blowers force heated air through the air fingers. The
BLOWER switch must be set to “ON” or “I” for oven
warmup and baking.
C. Gas Burner
The gas burner is located inside the rear panel and is
controlled by the temperature controller.
D. Cooling Fan — See Figure 1-5 and Figure 1-6
The cooling fan is located in the back of the oven. The
cooling fan draws air through its grille, blowing it through
the blower motor compartment and the control compart-
ments into the oven top and exhausted out the front
louvers.
E. Air Fingers and Blank Plates - See Figure 1-7
E1. Air Fingers
An Air Finger Assembly is made up of three parts:
1. Outer Plate - The Outer Plate is the removable covering
with tapered holes, which direct the air stream onto the
product being baked.
2. Inner Plate -The perforated Inner Plate is vital in forming
the unique air jets. It must be assembled into the manifold
with its holes aligned with the holes of the outer plate.
3. Manifold - The Manifold is the assembly which slides
on tracks into the oven plenum.
Figure 1-5. Machinery Compartment
Components
Blower Assembly
Right Control Box

SECTION 1
DESCRIPTION
5
Figure 1-6. Cooling Fan

6
SECTION 1
DESCRIPTION
Half Blank Plate
Blank Plate
Outer Plate
Inner Plate
Finger
Manifold
Assembly
Baffle
Figure 1-7. Blank Plates (two sizes) and an Air Finger.
F2. Blank Plates
1. Blank Plates- The Blank Plates are available to install
on the plenum where an air finger is not required.

SECTION 2
INSTALLATION
7
WARNING
Keep the appliance area free and clear of combustibles.
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.
CAUTION
For additional installation information, contact your local Authorized Service Agent.
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.
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 - For gas ovens, after any conversions, readjustments, or service work on the oven:
• Perform a gas leak test.
• Test for correct air supply.
• Test for proper combustion and gas supply.
• Check that the ventilation system is in operation.
NOTE
In Australia, the oven installation must conform with any requirements of the appropriate statutory authority.
Gas oven installtions must conform with AGA Codes AG311 and AG601.
NOTE
In Canada, the oven installation must conform with local codes. In the absence of local codes, gas oven
installations must conform with the Natural Gas Installation Code, CAN/CGA-B149.1, or the Propane Gas
Installation Code, CAN/CGA-B149.2, as applicable. Installed ovens must be electrically grounded in
accordance with local codes, or in the absence of local codes, with the Canadian Electrical Code CSA C22.2.
NOTE
In the USA, the oven installation must conform with local codes. In the absence of local codes, gas oven
installations must conform with the National Fuel Gas Code, ANSI Z223.1. Installed ovens must be
electrically grounded in accordance with local codes, or in the absence of local codes, with the National
Electrical Code (NEC), or ANSI/NFPA70.
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 supersede the
requirements and guidelines provided in this manual.
NOTE
In CE countries, all aspects of the gas supply connection must comply with current IEC/CEE requirements and
with all applicable local, national, and international codes. In addition, four casters are provided to allow the oven
to be more easily moved to the installation location. These casters are intended to simplify pre-installation
movement only, and are NOT suitable for use as part of a CE oven installation. During the installation procedure,
the casters MUST be removed, so that the oven can be supported by the supplied 152mm adjustable legs.
SECTION 2
INSTALLATION

8
SECTION 2
INSTALLATION
PARTS LIST FOR SERIES PS520 GAS OVEN
INSTALLATION KIT
Single Stack Oven
P/N 59182
ITEM
NO. QTY PART NO. DESCRIPTION
1 4 3101908 LEG 4″AD FT
2 2 48392 INSULATION BOTTOM TRAY
3 1 48394 BOTTOM TRAY WELDMENT
4 1 48396 TOP COVER
5 4 51387 SCREW MSSLT THREAD 8-32 × 1/2, 18-8
6 1 59223 OWNER'S OPERATING & INSTALLATION MANUAL
7 1 22450-0228 GAS HOSE RESTRAINT CABLE
8 1 22361-0001 GAS HOSE
NOTE: The oven, when installed, must be electrically
grounded in accordance with local codes, or in the ab-
sence of local codes, with the National Electrical Code
(NEC), or ANSI/NFPA70.
NOTE
There must be adequate clearance between
the oven and any adjacent combustible con-
struction. Clearance must also be provided
for servicing and for operation.
CAUTION
It is recommended that the oven be placed under
a ventilation hood for adequate air supply and
ventilation.
CAUTION
Do not obstruct the flow of ventilation air to and
from your oven. Do not obstruct the fan holes in
the rear of the unit.
I. UNLOADING
Your Middleby Marshall PS520-Series Oven is shipped
partially assembled. It will arrive in a carton on a crate.
Carton size for a PS520-Series Oven is:
44-1/4″(1124mm) Long ×
37-1/2″(953mm) Wide ×
23″(584mm) High ×
The crate and carton must be examined before signing the
Bill of Lading. Report any visible damage to the transport
company, and check for the proper number of crates. If
apparent damage is found, make arrangements to file a
claim against the carrier. Surface Interstate Commerce
Regulations (U.S.A.) require that the claim must be
initiated by the consignee within 10 days from the date that
the shipment is received.
7
8
Figure 2-1. PS520-Series Gas Oven Installation Parts

SECTION 2
INSTALLATION
9
Figure 2-1 (continued). PS520-Series Gas Oven Installation Parts
ITEM
NO. QTY PART NO. DESCRIPTION
1 2 48392 INSULATION BOTTOM TRAY
2 1 48394 BOTTOM TRAY WELDMENT
3 1 48396 TOP COVER
4 4 51387 SCREW MSSLT THREAD 8-32 × 1/2, 18-8
5 4 M3828 PIN, ALIGNMENT
6 1 59223 OWNER'S OPERATING & INSTALLATION MANUAL
7 1 22450-0228 GAS HOSE RESTRAINT CABLE
8 3 22361-0001 GAS HOSE
PARTS LIST FOR SERIES PS520 Gas OVEN
INSTALLATION KIT
Triple Stack Oven
P/N 59184
7
8
ITEM
NO. QTY PART NO. DESCRIPTION
1 2 48392 INSULATION BOTTOM TRAY
2 1 48394 BOTTOM TRAY WELDMENT
3 1 48396 TOP COVER
4 4 51387 SCREW MSSLT THREAD 8-32 × 1/2, 18-8
5 4 3101908 LEG 4″AD FT
6 1 59223 OWNER'S OPERATING & INSTALLATION MANUAL
7 1 22450-0228 GAS HOSE RESTRAINT CABLE
8 2 22361-0001 GAS HOSE
PARTS LIST FOR SERIES PS520 Gas OVEN
INSTALLATION KIT
Double Stack Oven
P/N 59183
7
8

10
SECTION 2
INSTALLATION
4.00
101.6mm
Figure 2-5. MODEL PS520 SINGLE OVEN DIMENSIONS
The Opening Height is Adjustable from 2-1/4 inch minimum
to 3-3/4 inch maximum in 1/2 inch increments.
1
1

SECTION 2
INSTALLATION
11
Figure 2-6. MODEL PS520 DOUBLE OVEN DIMENSIONS
4.00
101.6mm
1
The Opening Height is Adjustable from 2-1/4 inch minimum
to 3-3/4 inch maximum in 1/2 inch increments.
P/N 59927 is shown in its correct installed position.
1
2

12
SECTION 2
INSTALLATION
Figure 2-7. MODEL 520 TRIPLE OVEN DIMENSIONS
1
The Opening Height is Adjustable from 2-1/4 inch minimum
to 3-3/4 inch maximum in 1/2 inch increments.
P/N 59927 is shown in its correct installed position.
1
2

SECTION 2
INSTALLATION
13
WARNING
DO NOT USE CONDUIT OR GAS LINE
FOR GROUND CONNECTION.
CAUTION
IT IS RECOMMENDED THAT THE OVEN
BE PLACED UNDER A VENTILATION
HOOD FOR ADEQUATE AIR SUPPLY
AND VENTILATION.
ELECTRIC SUPPLY TO BE
PROVIDED BY CUSTOMER
CIRCUIT BREAKER
Separate circuit breaker with lockout/tagout electrical
shutoff for each oven. Wire each oven separately.
15A Amp circuit breaker for 208-240V.
ELECTRICAL SPECIFICATIONS
DOMESTIC: 208V main blower motors, 1 Ph, 1.5 Amp
draw, 50/60 Hz, 208-240V control circuit, 2 pole, 3 wire
system per oven (2 hot, 1 grd).
Do NOT use conduit for ground.
or
DOMESTIC or EXPORT: 240V main blower motors, 1 Ph,
1.5 Amp draw, 50/60 Hz, 208-240V control circuit, 2 pole,
3 wire system per oven (2 hot, 1 grd).
230V main blower motors, 1 Ph, 1.5 Amp draw, 50/60 Hz,
208-240V control circuit, 2 pole, 3 wire system per oven
(2 hot, 1 grd).
Do NOT use conduit for ground.
UTILITY ROUGH-IN DIMENSIONS AND POSITIONING
FOR PS520-SERIES OVENS
POWER RATING
40,000 BTU/hr (11.7 kW/hr.
SUPPLY WIRE
Supply wire size must be in accordance with the National
Electrical Code (current edition) and must be in compli-
ance with local codes.
SUGGESTED
If space permits, service should be located near the
control console end of the oven(s) to allow convenient
access to safety switches.
CAUTION
UNIT MUST HAVE AIR VENT PLATES IN-
STALLED OR WARRANTY WILL BE VOID.
II. VENTILATION GUIDELINES
A mechanically driven ventilation system is required for the
PS520 Series Middleby Marshall conveyorized gas ovens.
Local codes and conditions vary greatly from one area to
another and must be complied with. Following are the
suggested requirements for good ventilation. Please re-
member these are recommendations or guidelines, you
may have a special condition or problem that will require
the services of a ventilation engineer or specialist. Proper
ventilation is the oven owner’s responsibility. Improper
ventilation can inhibit oven performance.
Please Note: There are now two“stand off”
‘C’ Channels and the “plate” for “Double
and Triple Ovens” that must be installed in
the field.
Figure 2-9. Typical PS520-Series Oven(s)
Installation

14
SECTION 2
INSTALLATION
These ‘C’ Channel brackets are installed in the vertical
plane using existing screws (Item 6) to support these ‘C’
Channels using the upper and lower Key Hole openings in
the ‘C’ Channels. The ‘C’ Channels are identical and once
installed will allow ample amounts of air through the cooling
fan mounted on the rear side of the oven by keeping the
oven away from the rear wall.
III. ELECTRICAL CONNECTION INFORMATION
FOR PS520-SERIES OVENS.
WARNING
Authorized supplier personnel normally ac-
complish the connections for the ventilation
system, electric and gas supplies, as ar-
ranged by the customer. Following these
connections, the factory-authorized installer
can perform the initial startup of the oven.
Check the oven data plate (Figure 2-10) before making any
electric supply connections. Electric supply connections
must agree with data on the oven data plate.
NOTE: The electric supply installation must satisfy the
requirements of the appropriate statutory authority, such
as the National Electrical Code (NEC), ANSI/NFPA70,
(U.S.A.); the Canadian Electrical Code, CSA C22.2; the
Australian Code AG601; or other applicable regulations.
A fused disconnect switch or a main circuit breaker
(customer furnished) MUST be installed in the electric
supply line for each oven; it is recommended that this
switch/ circuit breaker have lockout/tagout capability. The
electric supply connection must meet all national and local
electrical code requirements. Copper is the recommended
material for the electrical supply conductors.
IV. ELECTRIC SUPPLY FOR GAS
HEATED OVENS
Power requirements for gas heated ovens are 208 -
240VAC, 1-phase, 3-wire (2 ‘hot’, 1 ground). Electrical
connection is made through a cord and plug. Using flexible
cable(s) for the electrical power supply conductors re-
quires a 2″(51mm) strain-relief fitting (not furnished) to
enable safe access to the terminal block from which oven
power is distributed.
The supply conductors must be of the size and
material (copper) recommended to provide the cur-
rent required; (refer to the data plate for the ampere
specifications). The electric current rating for each
conductor supplying a PS520-Series Oven is 1.5A.
Figure 2-11. Junction Connection Box
Figure 2-10. Typical Electric Oven Data Plate
ELECTRICAL
INLET
GAS INLET

SECTION 2
INSTALLATION
15
V. GAS SUPPLY
CAUTION
DURINGPRESSURETESTING NOTETHE FOLLOWING:
1. The oven and its individual shutoff valve must be discon-
nected from the gas supply piping system during any
pressure testing of that system at test pressure in excess
of 1/2 psi (3.45 kPa).
2. The oven must be isolated from the gas supply piping
system by closing its individual manual shutoff valve dur-
ing any pressure testing of the gas supply piping system
at test pressure equal to or less than 1/2 psi (3.45 kPa).
3. If incoming pressure is over 14″″
″″
″W.C. (35mbar), 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 regu-
lator during initial turn- on of gas, it is very important to
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.
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 - 650 cfh (307l/min) meter
Gas Line
• DEDICATED LINE from the gas meter to the oven
• 1-1/2" (50.8mm) pipe for natural gas
• 1-1/2″(38.1mm) pipe for propane
• Maximum length: 200' (61m). Each 90° elbow equals 7'
(2.13m) of pipe.
B. Gas Conversion
Ovens are shipped from the factory configured for use with
natural gas. If permitted by local, national and international
codes, the oven may be converted to propane gas operation
using a Gas Conversion Kit that is supplied with the oven. Gas
orifice sizes supplied with the Kit match those shown in the
Tables on page 2 in the Description section of this Manual.
Where permitted by local and national codes, it is possible to
convert ovens from natural to propane gas, or from propane to
natural gas, after the oven has been installed. Gas Conversion
Kits are available from Middleby Marshall for this purpose.
C. 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 discon-
nect 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, conver-
sions 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: Certain safety code requirements exist for the installation
of gas ovens; refer to the beginning of Section 2 for a list of the
installation standards. In addition:
• In the USA, the installation must conform with local codes,
or in the absence of local codes, with the National Fuel Gas
Code, ANSI Z223.1.
• In Canada, the installation must conform with local codes,
or in the absence of local codes, with the Natural Gas
Installation Code, CAN/CGA-B 149.1, or the Propane
Installation Code, CAN/CGA-B 149.2, as applicable.
• In Australia, the installation must conform with AGA Codes
AG311 and AG601, and with any requirements of the
appropriate statutory authority.
• In CE countries, the gas supply connection should be
according to EN-203 (gas appliance directive) and 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.
• For all ovens equipped with casters, the gas line connection
shall be made with:
- A connector that complies with the Standard for
Connectors for Movable Gas Appliances, ANSI Z21.69
(in USA), or Connectors for Movable Gas Appliances,
CAN/CGA-6.16 (in Canada).
Check the oven’s gas supply requirements to determine the
type of gas to be used with the oven. If the gas type required does
NOT match the local supply:
• For North American installations, a conversion kit is
supplied with the oven to allow operation using propane
gas. Refer to Part B, Gas Conversion, in this section.
• For CE ovens, directions for converting the oven for use with
other gases are described in Part D.1, Preparation for Use
with Various Gases, in this section.
If the installation will use the supplied gas hose, be sure that
the 1/2″to 3/4″gas line fitting is attached. Refer to the
instructions in the gas hose package. One gas line connection
method is shown in Figure 2-12; however, compliance with the
applicable standards and regulations is mandatory.
Inlet and regulated gas pressures can be measured using a “U” tube
manometer at the tap locations shown in Figures 2-12 and 2-13.
Figure 2-12 - Flexible Gas Hose Installation
To Gas
Supply
Pipe
90°
Elbow
Quick-
disconnect
device
Flexible
Gas Hose
Full-Flow
Gas
Shutoff
Valve
3/4" gas
pipe nipple
3/4"-1/2"
gas pipe
reducer
Individual gas
connection for
each oven
cavity
1/2" gas
pipe nipple
1/2" gas line
tee with
pressure tap

16
SECTION 2
INSTALLATION
1. Checking the Gas Supply (Inlet) Pressure
a. With the main gas supply valve closed and the circuit
breaker/fused disconnect in the OFF (“O”) position, open
the inlet pressure tap shown in Figure 2-13 and attach a
manometer to the tap.
b. Depress the safety switches to allow the oven to operate.
c. Open the main gas supply valve. Switch the circuit breaker/
fused disconnect to the ON (“I”) position.
d. Start the oven according to the directions in the Operation
section of this Manual. Adjust the temperature controller to
the maximum setting 600°F (316°C).
e. Measure the supply (inlet) pressure.
f. 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 close the inlet tap.
g. Compare the measured supply (inlet) pressure to the
nominal pressures shown in the Description section of
this Manual.
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 3.5″wc, or higher than 7″wc, contact the gas supplier. DO
NOT OPERATE THE OVEN or adjust the oven controls.
2. 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.
a. Orifice (Manifold) Pressure Method
1. With the main gas supply valve closed and the circuit
breaker/fused disconnect in the OFF (“O”) position,
open the manifold pressure tap shown in Figure 2-13
and attach a manometer to the tap.
2. Remove the cap screw from the pressure adjustment
screw (governor) on the gas control valve.
3. Depress the safety switches to allow the oven to operate.
4. Open the main gas supply valve. Switch the circuit
breaker/fused disconnect to the ON (“I”) position.
5. Start the oven according the directions in the Operation
section of this Manual. Adjust the temperature controller
to the maximum setting (316°C).
6. Adjust the pressure adjustment screw as necessary
to match the correct pressure for the oven's specific
gas type. Refer to the Pressure Table in the Description
section of this Manual. Turning the adjustment screw
clockwise increases the flow, while turning it
counterclockwise reduces the flow.
7. 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
close the manifold pressure tap.
Consumption (m3/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. Volumetric Method
1. Determine the time of 0.1m3(100 liters) of gas usage
as follows.
2. Check that the main gas supply valve and the circuit
breaker/fused disconnect are in the OFF (“O”) position.
3. Remove the cap screw from the pressure adjustment
screw (governor) on the gas control valve.
4. Depress the safety switches to allow the oven to operate.
5. Open the main gas supply valve. Switch the circuit
breaker/fused disconnect to the ON (“I”) position.
6. Start the oven according the directions in the Operation
section of this Manual. Adjust the temperature controller
to the maximum setting (316°C).
7. Adjust the pressure adjustment screw as necessary
to match the calculated volume using the time (in
minutes) of 0.1m3of gas usage. Turning the
adjustment screw clockwise increases the flow, while
turning it counterclockwise reduces the flow.
8. Record the reading obtained from the gas meter and
calculate the obtained gas flow. Compare this value
to the information in the tables in the Description
section of this Manual.
9. 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
gas control valve.
Figure 2-13 - Gas Control Valve
Mainfold
pressure tap
(where regulated
gas pressure is
measured)
Pressure
adjustment
screw
(under cap)