XLT XD-9006A User Manual
XD-9006A
GA-SWC-HB
04/09/2012
XLT Gas Oven & AVI Hood
Parts & Service Manual
This appliance is for professional use by qualified personnel. This appliance must be installed
by qualified persons in accordance with the regulations in force. This appliance must be installed with
sufficient ventilation to prevent the occurrence of unacceptable concentrations of substances harmful
to health in the room in which it is installed. This appliance needs an unobstructed flow of fresh air for
CAUTION
Electronic copies of this manual, Rough-In Specifications, Installation & Operation Manual, Architectural
Drawings, & a list of International Authorized Distributors are available at: www.xltovens.com
For use with the following XLT Gas Oven Versions:
Standard (S) C
World (W) C
satisfactory operation & must be installed in a suitably ventilated room in accordance with current
regulations. This appliance should be serviced by qualified personnel at least every 12 months or
sooner if heavy use is expected.
For use with the following AVI Gas Hood Versions:
Standard (S) B
World (W) B
2000887
XLT Ovens
PO Box 9090
Wichita, Kansas 67277
US: 888-443-2751 FAX: 316-943-2769 INTL: 316-943-2751 WEB: www.xltovens.com
2
WARNING & SAFETY INFORMATION
SAFETY DEPENDS ON YOU
Improper installation, adjustment, alteration, service or maintenance can cause property damage, injury, or death. Read the installation, operating and maintenance in-
WARNING
Post in a prominent location instructions to be followed in the event you smell gas. This infor-
mation can be obtained by consulting your local gas supplier.
WARNING
In the event a gas odor is detected, shut off the gas at the main shutoff valve immediately.
Contact your local Gas Company or supplier.
Do not restrict the flow of combustion and/or ventilation air to the unit. Provide adequate
clearance for operating, cleaning, & maintaining the unit & adequate clearance for operating
the gas shutoff valve when the unit is in the installed position.
Keep the area free & clear of combustible material. DO NOT SPRAY AEROSOLS IN THE
VICINITY OF THIS APPLIANCE WHILE IT IS IN OPERATION.
Ovens are certified for installation on combustible floors.
Electrical schematics are located inside the control box of the oven & and in this manual. Dis-
connect input power to the unit before performing any maintenance.
This unit requires a ventilation hood. The installation must conform to local codes.
This unit may be operated with either natural gas or LP fuel as designated on the nameplate
label located on the side of the unit.
This unit must be operated by the same voltage, phase, & frequency of electrical power as des-
ignated on the nameplate label located on the side of the unit.
Minimum clearances must be maintained from combustible & non-combustible construction
materials.
Follow all local codes when installing this unit.
Follow all local codes to electrically ground the unit.
Appliance is not to be cleaned with high pressure water.
XLT ovens are certified for use in stacks of up to three (3) units of XLT products. Integration
of other manufacturer’s products into an oven stack is not recommended, & will void any war-
ranties. XLT Ovens assumes no liability for mixed product applications.
Failure to call XLT Customer Service at 1-888-443-2751 prior to contacting a repair company
voids any & all warranties.
PLEASE RETAIN THIS MANUAL FOR FUTURE REFERENCE.
structions thoroughly before installing, using, or servicing this equipment.
FOR YOUR SAFETY
Do not store or use gasoline or other flammable liquids or vapors in
the vicinity of this or any other appliance.
XLT Ovens has spent millions of dollars designing and testing our products as well as de-
veloping Installation & Operation Manuals. These manuals are the most complete and easiest to
understand in the industry. However, they are worthless if they are not followed.
We have witnessed store operators and building owners lose many thousands of dollars in
lost revenue due to incorrect installations. We highly recommend you follow all instructions given
in this manual as well as follow best practices in plumbing, electrical, and HVAC building codes.
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WARNING & SAFETY INFORMATION
Definitions & Symbols
A safety instruction (message) includes a “Safety Alert Symbol” & a signal word or phrase
such as WARNING or CAUTION. Each signal word has the following meaning:
This symbol indicates high voltage. It calls your attention to items or operations
that could be dangerous to you & other persons operating this equipment. Read the
HIGH
VOLTAGE
WARNING
CAUTION
message & follow the instructions carefully.
Indicates a potentially hazardous situation that, if not avoided, can result in serious
injury or death.
Indicates a potentially hazardous situation, that if not avoided, can result in minor
to moderate injury or serious damage to the product. The situation described in the
CAUTION may, if not avoided, lead to serious results. Important safety measures
are described in CAUTION (as well as WARNING), so be sure to observe them.
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NOTE
TIP
Notes indicates an area or subject of special merit, emphasizing either the product’s
capability or common errors in operation or maintenance.
Tips give a special instruction that can save time or provide other benefits while installing
or using the product. The tip calls attention to an idea that may not be obvious to first-time
users of the product.
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WARRANTY - US & Canada
XLT warrants gas ovens manufactured after April 1, 2009 utilizing quietFIRE™ burners
and all electric ovens manufactured after April 1, 2011 to be free from any defect in material and
workmanship under normal use for five (5) years from the date of original purchase by the end
user, and further warrants main fan blades, conveyor shafts, and conveyor bearings for ten (10)
years. XLT further warrants all ovens to be free from rust for ten (10) years from the date the
equipment is originally purchased. XLT warrants AVI hoods to be free from any defect in material and workmanship under normal use for two (2) years from the date of original purchase by the
end user. In the event of a part failure, XLT will furnish a replacement part and pay for all labor
associated with the replacement of the part if, upon inspection, XLT determines that the part is defective. This warranty is extended to the original end user purchaser and is not transferable without prior written consent of XLT. Damages are limited to the original purchase price.
DUTIES OF THE OWNER:
The owner must inspect the equipment and crates at time of receipt. Damage during shipment
is to be immediately reported to the carrier and also to XLT.
The equipment must be installed and operated in accordance with the written instructions fur-
nished with the unit.
This warranty shall not excuse the owner from properly maintaining the equipment in accor-
dance with the written instructions furnished with the unit.
A copy of the “Initial Start-Up Checklist” must be filled out and returned to XLT Ovens and
the Authorized Distributor when the unit is initially installed, and/or when the unit is removed
and installed in another location.
The gas, electric, and HVAC utilities must be connected to the oven and installed by locally
licensed contractors.
Failure to contact XLT Ovens prior to contacting a repair company for warranty work voids
any and all warranties.
WHAT IS NOT COVERED:
The following items are not covered by this warranty:
Freight damage
Any part that becomes defective because of utility services (power surges, high or low volt-
ages, high or low gas pressure or volume, contaminated fuel, or improper utility connections)
Conveyor belts
Filters
Exhaust Fans
Light Bulbs
Normal maintenance or adjustments
This warranty shall not apply if the equipment or any part is damaged as a result of accident,
casualty, alteration, misuse, abuse, improper cleaning, improper installation, improper operation, natural disasters, or man-made disasters.
CLAIMS HANDLED AS FOLLOWS:
Should any such defect be discovered, XLT must be notified. Upon notification, XLT will arrange
for necessary repairs to be made by an authorized service agent. Denial of services upon the arrival of an authorized service agent will release XLT of any and all warranty obligations.
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LIMITED WARRANTY - INTERNATIONAL
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XLT warrants gas ovens manufactured after January 1, 2011 utilizing quietFIRE™ burners
and all electric ovens manufactured after April 1, 2011 to be free from any defect in material and
workmanship under normal use for two (2) years from the date of original purchase by the end
user. XLT warrants AVI hoods to be free from any defect in material and workmanship under normal use for one (1) year from the date of original purchase by the end user. In the event of a part
failure, XLT will furnish a replacement part to the Authorized Dealer if, upon inspection, XLT determines that the part is defective. The Authorized Dealer will pay for all labor associated with the
replacement of the part. This warranty is extended to the original end user purchaser and is not
transferable without prior written consent of XLT. Damages are limited to the original purchase
price.
DUTIES OF THE OWNER:
The owner must inspect the equipment and crates at time of receipt. Damage during shipment
is to be immediately reported to the carrier and also to XLT.
The equipment must be installed and operated in accordance with the written instructions fur-
nished with the unit.
This warranty shall not excuse the owner from properly maintaining the equipment in accor-
dance with the written instructions furnished with the unit.
A copy of the “Initial Start-Up Checklist” must be filled out and returned to XLT Ovens and
the Authorized Dealer when the unit is initially installed, and/or when the unit is removed and
installed in another location.
The gas, electric, and HVAC utilities must be connected to the oven and installed by locally
licensed contractors.
Failure to contact the Authorized Dealer prior to contacting a repair company for warranty
work voids any and all warranties.
WHAT IS NOT COVERED:
The following items are not covered by this warranty:
Freight damage
Any part that becomes defective because of utility services (power surges, high or low volt-
ages, high or low gas pressure or volume, contaminated fuel, or improper utility connections)
Conveyor belts
Filters
Exhaust Fans
Light Bulbs
Normal maintenance or adjustments
This warranty shall not apply if the equipment or any part is damaged as a result of accident,
casualty, alteration, misuse, abuse, improper cleaning, improper installation, improper operation, natural disasters, or man-made disasters.
CLAIMS HANDLED AS FOLLOWS:
Should any such defect be discovered, the Authorized Dealer must be notified. Upon notification,
the Authorized Dealer will arrange for necessary repairs to be made by an authorized service
agent. The Authorized Dealer will notify XLT Ovens of all discovered defects.
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6
This manual, which contains an illustrated parts breakdown, has been prepared as an aid in
understanding how the unit operates, how to diagnose problems, and order parts for the equipment.
All of the parts, listed in the parts breakdown, are manufactured with the same precision as the
original equipment.
XLT parts and service providers are available worldwide. There are authorized service
providers located in the principle cities of the United States. There are also authorized Distributors
located throughout the world.
The Theory of Operation section describes how the unit operates. An understanding of
normal operation will greatly aid diagnosis and troubleshooting. The Troubleshooting section asks
simple yes or no questions. The next question or statement entirely depends upon the previous answer. It will lead to the solution of a problem in the most efficient way. The illustrated parts section identifies the various sub-assemblies and detailed parts which make up the equipment, as well
as the part number. An explanation of how to order parts is included.
This manual is designed to supplement the Installation & Operation Manual provided with
the unit when new. Please refer to it for descriptions, dimensions, weights, electrical requirements,
maintenance schedules, and certifications.
XLT Ovens wants you to be totally satisfied with every aspect of owning & using your
oven & hood. Your feedback, both positive & negative, is very important to us as it helps us understand how to improve our products & our company. Our goal is to provide you with equipment
that we can be proud to build & you can be proud to own.
To receive technical support for the oven or hood you purchased, XLT has qualified customer service personnel that can provide assistance on any type of XLT oven or hood equipment
problem you may experience. Customer Service is available 24/7/365 at 888-443-2751 or visit
www.xltovens.com.
GENERAL
Repairs of all electric appliances & ventilation exhaust hoods should only be performed by a qualified professional who has read & understands these instructions &
is familiar with proper safety precautions. Read this manual thoroughly before in-
WARNING
stalling or servicing this equipment.
Save this Manual
This document is the property of the owner of this equipment.
XLT Ovens reserves the right to make changes in design & specifications, and/or make additions to or improvements to its product without imposing any obligations upon itself to install
them in products previously manufactured.
All Right Hand & Left Hand designations in this manual are from the point of view as if
standing directly in front of the glass sandwich door.
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TABLE OF CONTENTS
Warning & Safety Information..................................................................................................... 2
Warranty ....................................................................................................................................... 4
General ......................................................................................................................................... 6
Oven Theory of Operation ........................................................................................................... 8
Hood Theory of Operation ......................................................................................................... 14
Oven Troubleshooting ................................................................................................................ 17
Hood Troubleshooting ................................................................................................................ 18
Oven Service Procedures............................................................................................................ 20
Hood Service Procedures ........................................................................................................... 26
Oven Parts .................................................................................................................................. 28
Hood Parts .................................................................................................................................. 47
Accessories ................................................................................................................................. 50
Oven Schematics ........................................................................................................................ 53
Hood Schematics ........................................................................................................................ 59
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For maintenance procedures, please refer to the XLT Installation & Operation Manual.
Revision History Table
Revision Comments Date
A New Release 04/09/2012
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8
When the Main Switch (S1) is turned on;
1. The Oven Fan Motor (M1) located in the Back Wall will run.
2. The Fan (M3) located on the Control Panel will run.
3. The Temperature Control (TC) should display both the actual and set-point temperatures.
4. The Conveyor Control (CC) should display the belt time.
5. The burner will ignite.
6. The conveyor belt should move.
The first part of the Theory of Operation explains how electrical power is delivered to the
oven and initial sequences when the main operator switch is turned on. The remainder of the Theory of Operation section explains the function of components in alphabetical order. These components are also listed on the schematic.
Line voltage for Standard Ovens is assumed to be 120 VAC, 60 Hz.
Line voltage for World & Australian Ovens is assumed to be 230 VAC, 50 Hz.
Power originates at the electrical connection on the wall. Line voltage is then carried into
the oven through the power cord to the Terminal Strip (TS). The Neutral line is connected to the
TS, and several jumpers are used to bridge along the TS to make connection points for multiple
neutral lines from all components inside of the control box and Main Fan motor. Line 1 is also
connected to the TS. From there, wires connect to Terminal T11 on the Cool Down Timer (R1),
the High Limit Switch (S3, World & Australian only), through the Main Circuit Breaker (CB1),
then to the Main Switch (S1). Unless the outlet on the wall has no power, the circuit just described
has power at all times.
When S1 is turned on, line voltage will be carried thru the switch simultaneously to four
locations via two parallel circuits:
Terminal T6 of the Cool Down Timer (R1)
Terminal T5 of the Temperature Control (TC), via a Circuit Breaker (CB5)
Combustion Blower Motor (M4) via CB5 (Australia only)
And:
Transformer (XFMR)
Power Supply (PS)
GAS OVEN THEORY OF OPERATION
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GAS OVEN THEORY OF OPERATION
BC - The Burner Control (BC) is powered by 24 VAC from the Transformer (XFMR). Incoming
power will be interrupted by the Temperature Control (TC) when the actual temperature rises
above the Maximum Operating Temperature (see Specification Sheet). When the BC receives
power, it initiates a pre-purge lighting sequence. A red LED will blink once after about 2-3 seconds to give notification that the lighting sequence has started. After about 30 seconds, two events
occur; 1) a high-voltage electrical signal will be sent to the Flame Sensor/Spark Igniter (FS/SI)
from the Spark Terminal, and 2) a 24 VAC signal will be generated across Terminals V1 & V2.
The high voltage jumps across a gap in the FS/SI creating a spark that can be heard, although the
BC only produces this spark for four (4) seconds. One end of the Rectifier Plug is connected to
Terminals V1 & V2 through a Circuit Breaker (CB6). The Rectifier Plug rectifies the 24 VAC to
24 VDC. The other end of the Rectifier Plug is connected to Terminals 1 & 4 of the Main Valve
(V1-V2). The V1-V2 valve will open, allowing fuel to flow into the burner. When the two simultaneous events occur, fuel flow and spark, ignition should occur. When flame is sensed by the FS/
SI, a DC current is sent to Terminal S1 of the BC. The BC uses this DC current to prove ignition.
A minimum of .7 µA is required to maintain operation. If the Burner lights, the LED will not
flash. If the Burner fails to light, the LED will flash three (3) times, repeatedly, and the BC will
not attempt to re-light.
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CAP - The Capacitor is physically mounted inside the Control Box but wired to the externally
mounted Main Motor. The Main Motor is a permanent split capacitor (PSC) motor. PSC means a
capacitor motor in which the starting capacitor and the auxiliary winding remain in the circuit for
both starting and running.
CB - Circuit Breakers are used to protect electrical components. The current value is printed on
the front of all breakers. If a CB is tripped, eliminate the cause and press the front to reset.
CC - The Conveyor Control is supplied 24 VDC by the Power Supply (PS) via a Circuit Breaker
(CB3 & CB4, optional) to Terminals #4 & 5. The belt time is displayed, and is user-adjusted by
pressing and holding the up or down arrow button switches. See the Specification Sheet for minimum and maximum belt times. The motor speed is calculated based on the time that is entered.
This time is translated to a RPM on the motor shaft depending on the size of the oven, the diameter
of the sprocket, and the gear ratio of the gearbox. Once the motor is running, hall sensor inputs are
fed back into the driver to determine the speed the motor is currently running at. This input goes
into a PID algorithm to adjust the PWM output to control the speed to match the target speed that
was calculated first. This PWM is adjusting the average voltage that the motor phases are seeing.
As the average voltage goes up, the motor will speed up. As the average voltage drops, the motor
speed will also drop. The maximum speed is based on a continuous 18-24V being supplied to the
motor. The phasing of the controller is dependent on the hall sensor signals that are being returned. The controller reads the hall sensor position and from there knows which phase of the motor receives the 18-24V signal, which phase of the motor is the return and which phase of the motor is left open. As the motor spins, the hall sensors change, which dictate which phases are energized.
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FS/SI - The Flame Sensor/Spark Igniter consists of a copper-clad metal mounting plate, a ground
electrode, and two additional electrodes encapsulated in ceramic insulators. One of the insulated
electrodes has a 1/4” male spade welded to it while the other insulated electrode has a 3/16” male
spade welded to it. The rod with the 1/4” spade connects to the Spark Terminal on the Burner
Control (BC) via a spark wire. The end of this rod is positioned near the ground electrode in such
a way so as to create a small gap. When the high-voltage signal from the BC reaches the gap, it is
forced to jump the gap resulting in a spark.
Flame has the unique ability to rectify AC voltage and current into DC voltage and current.
The electrode with the 3/16” spade is positioned in such a way so that the electrode is inside the
flame envelope. A wire connects this electrode to Terminal S1 on the BC. A green ground wire is
attached to the copper-clad mounting plate, and connected to chassis ground inside the control box.
When flame is present, a DC current flow is detected by the BC. The amount of current flow is
determined by the position of the flame sensor and the size of the flame. The minimum current
flow to maintain operation is .7 µA.
M1 – The Main Motor is a Permanent Split Capacitor (PSC), single phase, capacitor run motor and
has an internal centrifugal switch (S2). The motor is dual voltage and reversible. The voltage to
power the motor comes from the Cool Down Timer (R1), and the motor will continue to operate
for approximately 30 minutes after the main switch is turned off. There are no user serviceable
parts in the motor, and the bearings are permanently lubricated.
GAS OVEN THEORY OF OPERATION
M2 - The Conveyor Motor (M2) is a brushless 24 VDC gear motor. The motor receives current
from the Conveyor Control (CC) through three (3) wires; 1) A black or “W” phase, 2) a white or
“V” phase, and 3) a red or “U” phase. They carry between 18 to 24 VDC. Each wire is energized
by the Conveyor Control (CC) in sequence to provide power to the individual stator coils which, in
turn, provide motor rotation.
To determine the rotors position and send this position to the controller, three (3) Hall Effect switches are utilized. They read the rotational information from a disc mounted on the rotor
assembly. This information is transmitted to the CC by three (3) wires; 1) an orange “U” phase
pole signal output, 2) a green “V” phase pole signal output, and 3) a green/white “W” phase pole
signal output. These are located in a plug that inserts into the CC. There are two (2) additional
wires in this plug; 1) a purple wire which is supply voltage for the pole sensor, and 2) a gray wire
that is ground.
The CC, using an internal logic circuit, energizes the stator coils to provide proper rotation
and sets the energization (phase) timing to obtain the desired belt speed set on the controller.
The motor drives an integral gear box that reduces the motor output speed to give the correct travel
time to the conveyor belt. The integral gear box is sealed and permanently lubricated with grease.
The ratio is 1/200.
M3 - The Flow Path Pressure Generating (FPPG) fan supplies combustion air for the Burner. It is
wired in parallel with M1 and will continue to operate for 30 minutes after S1 is turned off. A filter is provided to ensure clean air.
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GAS OVEN THEORY OF OPERATION
M4 - (Australia ovens only) - The Burner Blower Motor is a dual-voltage, shaded pole motor that
supplies air for combustion. A Centrifugal Switch (S4) is physically mounted internally to prove
rotation.
PS - The Power Supply rectifies line voltage to 24 VDC, and supplies power to the Conveyor Control (CC). A 4 amp fuse is used to provide over current protection, which is mounted on the PS
itself. There are no other fuses used anywhere else.
PU - The Pick-Up is physically mounted within the Conveyor Motor (M2) and utilizes hall effect
technology integral to the M2 to monitor the rotation speed. The hall effect signal is transmitted to
the CC, which converts it into linear travel speed of the conveyor.
R1 - R1 is a 30-minute off delay relay which functions as a cool down timer. Applying power to
T6 activates the relay, which sends a voltage signal out from T9. When power is removed from
T6, voltage continues from T9 for 30 minutes. T9 supplies voltage to the Main Fan Motor (M1)
through a Circuit Breaker (CB2), and also supplies voltage to the FPPG (M3) Fan. M1 and M3 are
the only components that will continue to operate for 30 minutes after S1 is turned off. The off
delay relay is a safety feature to allow the oven to cool down to room temperature, and to eliminate
heat stress on the components of the oven.
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R2 - Proving Relay (Australia ovens only) - The proving relay is a safety device to ensure that the
Temperature Control (TC), Signal Conditioner (SC), and the Burner Control (BC) do NOT have
24 VAC until the Burner Blower Motor (M4) is spinning at full speed. The proving relay proves
that there is no M4 rotation. Once M4 achieves full RPM, R2 works in conjunction with the Centrifugal Switch (S4) to prove that there is fan rotation.
24 VAC is supplied by the XFMR to terminal 6 on R2. At this point in time, this serves no
function. An additional wire connects terminal 6 with the common switch contact of S4. When
the motor is at rest, 24 VAC is carried through NC switch contacts in S4 to terminal 9 on R2. At
this point in time, this also serves no function. Another wire connects terminal 9 to terminal A to
activate the relay coil. When the coil in R2 is activated, the relays switch state. When that happens, then 24 VAC is carried from terminal 6 to terminal 9, which supplies power to terminal A in
order to keep the coil energized. These events occur in a very short amount of time.
When M4 achieves full RPM, S4 will change state. Voltage will then be applied to terminal 4 of R2. Since R2 is energized, terminal 4 is connected to terminal 7, which supplies 24 VAC
to TC, SC, & BC.
If the main switch is cycled, the XFMR will disable and not supply the proving relay voltage and the proving relay will go back to NC. Before reactivating R2, M4 must come to a complete stop or S4 will not go back to NC to reactivate proving relay.
RP – The Rectifier Plug has an integrated full-wave bridge rectifier circuit. It converts 24 VAC
from the Burner Control (BC) into 22 VDC that is sent to the Multi-Valve (V1-V2).
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S1 - The Main Switch is a SPST normally open switch, mounted on the front of the Control Box.
Activating this switch applies voltage to Terminal T6 of the Cool-Down Timer (R1) and to the primary side of the Transformer (XFMR). When used with the optional AVI Hood System, a remote
switch mounted in the front of the AVI Hood replaces it.
S2 - This Switch is a SPDT centrifugal switch physically mounted inside the Main Motor (M1).
When M1 comes up to full speed, S2 closes and sends a 24 VAC signal to the Temperature Control (TC) and the Signal Conditioner (SC). It functions as a safety feature to prevent burner operation if the M1 fails to rotate.
S3 - High Limit Switch (World & Australia ovens only). This is a bi-metal, NC, SPST switch
physically mounted in the side panel of the Bake Chamber. It’s purpose is to provide fail safe op-
eration. If the temperature of S3 exceeds 600°F, it opens and interrupts line voltage to all components except the Main Motor (M1).
S4 - (Australia ovens only) The Centrifugal Switch is SPST switch physically mounted inside the
Burner Blower Motor (M4) to prove rotation.
SC - The Signal Conditioner is powered by 24 VAC from the Transformer (XFMR) via the Main
Motor Centrifugal Switch (S2) and the Temperature Control (TC) on terminals 1 & 2. Incoming
power will be interrupted by the Temperature Control (TC) when the actual temperature rises
above the Maximum Operating Temperature (see Specification Sheet). The function of the SC is
to convert a 4-20 mA signal from the TC (Temperature Control) to a 45-250 mA signal and then
applies that signal to the Moduplus valve. This in turn modulates the valve to allow an appropriate
amount of fuel to control temperature.
GAS OVEN THEORY OF OPERATION
T/C - The thermocouple is a type K. It consists of two different conductors that produce a voltage
proportional to a temperature difference between either end of the pair of conductors. The T/C is
connected to Terminals 9 & 10 of the TC (Temperature Control). The milli-volt signal is used to
display the actual temperature.
TC - The Temperature Control (TC) has line voltage applied to terminal T5, and neutral voltage
applied to terminal T4. There are two displays; one for actual temperature and one for set-point
temperature. Actual temperature is determined by the Thermo-Couple (T/C), connected to terminals 9 & 10, with T9 being the negative terminal and T10 being the positive terminal. The user
determines the set-point temperature by pressing and holding the <UP> or <DOWN> arrow button
switches. The TC sends a 4-20 mA (milli-amp) signal to the Signal Conditioner (SC) depending
upon the relationship between actual temperature and set-point temperature. An alarm relay exists
between terminals 1 & 2. Incoming power will be interrupted by the Temperature Control (TC)
when the actual temperature rises above the Maximum Operating Temperature (see Specification
Sheet). The voltage being interrupted is 24 VAC from the Transformer (XFMR) to the Signal
Conditioner (SC) and Burner Control (BC) combined. The Maximum Operating Temperature is
set at the factory and cannot be field adjusted.
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GAS OVEN THEORY OF OPERATION
V1-V2 & V3- The Multi-Valve assembly has three (3) Gas Valves. The Main Valves (V1-V2)
operate in series, and are wired in series via the Rectifier Plug. The Rectifier Plug rectifies 24
VAC from the Burner Control (BC) to 22 VDC. V1-V2 are solenoid valves and are open continuously during burner operation, regardless of either actual or set-point temperature values. V3 is a
modulating valve, and is controlled by a variable electrical signal from the Signal Conditioner
(SC). There are two (2) fuel pressure testing ports; one for incoming pressure, and one for both
high-bias and low-bias pressure. The upper port is used for incoming pressure, while the lower
port is used for high- and low-bias pressure. There are two (2) hex adjusting nuts; an 8mm nut for
adjusting high-bias pressure, and a 5mm nut for adjusting low-bias pressure.
XFMR- The Transformer steps down line voltage to 24 VAC. It supplies power to the Signal
Conditioner (SC), Burner Control (BC), and the Centrifugal Switch (S2). One terminal on the secondary side is connected to chassis ground by a green wire. The XFMR is ON whenever the Main
Switch (S1) is on, and is independent of the Cool Down Timer (R1). Note: The XFMR is
equipped with an integrated circuit breaker for standalone protection.
13
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14
When any one of, or all of, the Hood Operator Switches (S2, S3, & S4) are turned on;
1. The Exhaust Fan Motor (M1) located on the roof will run.
2. The Variable Frequency Drive (VFD) will display a set value. The values are preset from the
factory and can be referenced in the I&O manual.
3. The ovens associated with the corresponding switches will turn on.
The first part of the Theory of Operation explains how electrical power is delivered to the
hood and initial sequences when the main operator switch is turned on. The remainder of the Theory of Operation section explains the function of components in alphabetical order. These components are also listed on the schematic.
Line voltage for Standard Hoods is assumed to be 208/240 VAC, 60 Hz. (1) Phase
Line voltage for World & Australian Hoods is assumed to be 230 VAC, 50 Hz. (1) Phase
Power for the hood originates at building’s electrical service panel. Two (2) circuits are
required; 1) is a three phase circuit for VFD/Fan circuit, and 2) is a single phase circuit for lights
and relays. The single phase circuit consist of a line and a neutral, and connects to the Terminal
Strip (TS). A wire connects the TS to Switch 1 (S1-SPST-NO), which operates the lighting circuit, and also to Switch 5 (S5-SPST-NC), which is used to manually override the Variable Frequency Drive (VFD) in case of failure. The three phase circuit also connects to the TS, and wires
connect the VFD through Relay 7 (R7-3PDT) and a Circuit Breaker (CB). The single phase and
three phase circuits just described should have power at all times. The green run indicator directly
above the programming indicator is illuminated when the controller is in the run mode. The controller is put in run mode by pressing the green run button.
Power for ovens are routed through the hood to Switches 2, 3, & 4 (S2, S3, S4, all DPDTNO) via a Switch Relocation Cord (SRC). When XLT Ovens are installed with an AVI Hood, the
SRC effectively eliminates the Main Switch located on the oven and transfers control to the DPDT
switches on the hood.
When the contacts of S1 are closed, single phase voltage will be carried thru the switch to
the light bulbs.
When the contacts of S2, S3, or S4 are closed, the 1st set of contacts perform the exact
same function as S1 does on the oven. In addition, they allow current to flow through coils located
in Relay 1, 2, or 3 (R1, R2, R3, all SPST NO) which closes the Relay contacts to provide a signal
out to Make Up Air (MUA) dampers located in Roof Top Units (RTU).
The 2nd set of contacts will connect terminal P24 of the VFD to either terminal 1, 2, or 3,
which will initiate operation of the VFD.
CB - Circuit Breakers are used to protect electrical components. If a CB is tripped, eliminate the
cause and press the front to reset.
HOOD THEORY OF OPERATION
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HOOD THEORY OF OPERATION
CS - The Current Sensor is a device that detects electrical current in a wire, and then generates a
signal proportional to it. It drives an LED indicator lamp (L3) to indicate that the VFD is drawing
current and operating. A minimum of 1.5 AAC is required.
L1 & L2 - These are standard incandescent light bulbs, and should illuminate when the contacts of
S1 are closed.
L3 – This is a green LED indicator that is driven by the CS to indicate that the VFD is drawing
current and operating.
M1 – The Exhaust Fan Motor is a 3-phase, direct drive motor. In normal operation, it is powered
by the VFD through R6, and it’s RPM will vary as the frequency from the VFD varies. In Manual
Mode, it is powered with line voltage and frequency by R7 and R5, and will run full speed. There
are no user serviceable parts in the motor, and the bearings are permanently lubricated.
PLUG 1, 2, & 3 – These are circular electrical plugs on one end of the Switch Relocation Cord
(SRC). The Plugs connect to Receptacles 1, 2, & 3 on the bottom of the Hood Control Box. The
other end of the SRC plugs into the oven wire harness, and eliminates the operator switch supplied
in the oven. Conversely, when the operator switch on the hood is turned off, the corresponding
oven is turned off as well.
R1, R2, & R3 – These are SPDT relays, which are electrically operated switches. They use an
electromagnet to operate a switching mechanism. When the contacts of S2, S3, or S4 are closed,
current flows through a coil in the relays, causing the contacts in the relay to close. This will complete a circuit in the Dampers in the Roof Top Units (RTU).
R4 - This is a SPDT relay, which is an electrically operated switch. They use an electromagnet to
operate a switching mechanism. R4 is activated by fire alarm switch located in fire suppression
cabinet. When this NO switch is activated, voltage from P24 of VFD connects to terminal 4 of
VFD. This signals the VFD to advance the exhaust fan to full speed (60 HZ)
R5, R6, & R7 – These are 3PDT relays, which are electrically operated switches. They use an
electromagnet to operate a switching mechanism. R7 is used all of the time, regardless of whether
the unit is in normal operating mode or in manual mode. R5 & R6 are only used in manual mode.
R8 - This is a 3PDT relay (Standard Ovens) It is also a DPDT for (World Ovens), which is an
electrically operated switch. They use an electromagnet to operate a switching mechanism. R8 is
activated by fire alarm switch located in fire suppression cabinet. When this NO switch is activated, it then opens R8 disrupting the voltage to REC1-REC3.
REC 4, 5, & 6 - These are circular electrical receptacles mounted on the bottom of the Hood Control Box. They connect to the SRC and also to S2, S3, & S4. See PLUG 1, 2, & 3.
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16
S1 - This SPST (NO) switch is located on the front of the hood and controls the lights.
S2, 3, & 4 - These DPST (NO) switches are located on the front of the hood and control the ov-
ens, as well as initiating and sequencing the operation of the VFD and damper circuits.
Line voltage is continuously applied to pin 1 of REC 4, 5, & 6, which is connected by a
wire to a contact in S2, 3, & 4. This is shown on the schematic as the lower RH connection point
of S2, 3, & 4. When the switch contacts are closed, shown on the lower LH connection point on
the schematic, power is applied to pin 2 of the receptacles, as well as terminal B of R1, 2, & 3.
Wires also connect terminal B and pin 4 of the receptacles. In essence, S2, 3, & 4 replace the
switches on the ovens, and also energize the coils of R1, 2, & 3, which closes the relay contacts
and send a signal to dampers in RTU’s.
The other set of contacts, shown as the upper set on the schematic, connect terminal 24 of
the VFD and terminals 3, 2, & 1 respectively. The VFD generates it’s own 24 VDC signal volt-
age, and the switches serve as inputs to the VFD. The VFD outputs user-selected frequencies depending upon the combination of switches that are closed.
S5 & S6 - These are keyed SPST switches that are used for manual mode operation in case of
VFD failure. S5 is NO (OFF) and S6 is NO (OFF). When S5 is OFF, the key cannot be removed.
It can only be removed when the switch is turned ON. The same key is used to operate S6, and
can only be inserted or removed when S6 is OFF.
Incoming line voltage is applied to terminals 7, 8, & 9 on R7. In normal mode, the voltage is connected to terminals 1, 2, & 3, which feed the VFD. When the contacts of S5 are closed, in manual
mode, the incoming line voltage is connected to terminals 4, 5, & 6, causing the voltage to be diverted away from the VFD and sent to terminals 7, 8, & 9 of R5. S5 is also connected to R6, and
when the contacts of S5 are closed, the switch contacts of R6 change state, resulting in the complete isolation of the VFD on both the input and output sides.
At this point in time, there should be no voltage supplied to either the VFD or M1.
The key is then removed from S5 and inserted into S6. When the contacts of S6 are closed, the
contacts of R5 change state and incoming power and frequency is applied to M1 via the TS.
TS - this is a terminal strip, which serves as a connection point for wires.
VFD - The Variable Frequency Drive (VFD) converts the AC supply voltage to DC and then con-
verts the DC to s suitable three-phase frequency source for M1. Incoming power connects to terminals L1, L2, & L3. M1 connects to terminals U, V, & W through R6 & TS1. The VFD generates it’s own 24 VDC control voltage on terminal P24. S2, S3, & S4 serve as user-controlled inputs and connect terminals 1, 2, & 3 to terminal P24. User inputs include a <RUN> and <STOP/
RESET> button switch, as well as <UP> and <DOWN> arrow button switches. A complete manual can be found at www.xltovens.com.
HOOD THEORY OF OPERATION
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OVEN TROUBLESHOOTING
Mechanical Function
If your oven does not function properly, please verify the following conditions:
1. Verify that the power cord to the oven is connected and/or plugged in if equipped with a plug
and receptacle.
2. Check to see that the circuit breakers in the building electrical service panel have not been
tripped or turned off.
3. Check all circuit breakers on the oven control panel to ensure they have not been tripped.
4. Gas line size and pressure must be adequate to support total BTU requirements with all appliances in store turned on. Refer to the “Oven Gas Requirements” section of this manual.
5. Check the quick-disconnect on the gas hose to verify that it is fully and completely engaged.
6. Check the Manual gas valve to verify that it is turned on completely. The handle on the valve
should be parallel with the gas piping when the valve is turned on, and the handle will be perpendicular with the gas piping when the valve is turned off. Also remember that anytime the
gas hose has been disconnected it will take time to purge the air from the gas train.
17
7. Check to see that the oven is fully assembled. All of the fingers must be properly installed.
Incorrect or incomplete finger placement can cause a “windy” condition that can cause the
burner not to light.
If your oven still does not function properly, XLT has qualified customer service personnel
that can provide assistance on any type of XLT oven problem you may experience. Customer Service is available 24/7/365 at 888-443-2751, or visit www.xltovens.com. An interactive troubleshooting guide is available on the website.
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18
Before troubleshooting the hood:
1. Make sure that the RUN lamp and POWER lamp are lit.
2. Check to see that the breaker in the service panel is not tripped.
3. Check to see that the breaker on the hood electrical box is not tripped.
4. Make sure the Switch Relocation Cords (SRC) are properly installed to the oven(s).
5. Check to see that the grease filters are clean & installed properly.
6. Check to see if the exhaust fan is rotating in the correct rotation. (applies to new installations)
In the occurrence that the VFD controller has an ERROR Code displaying. Follow these steps to
clear them.
Error Codes:
E01-E04 Inverter output was short circuited
E05 motor overload is detected by electronic thermal function.
E07 DC bus voltage exceeds a threshold
E09 DC bus voltage is below a threshold
E14 Ground fault detected between controller output and motor.
Error Code Reset:
Check VFD display for error code and record it.
Clear error by pressing the <Stop Reset> button.
Press the <Run> button to activate exhaust fan.
Normal operation resumes with no error codes.
If error codes return press the <Stop/Reset> key and call XLT service.
HOOD TROUBLESHOOTING
If the corrective actions listed above do not correct the problem, then XLT has qualified
customer service personnel that can provide assistance on any type of XLT Oven or AVI Hood
problem you may experience. Customer Service is available at 888-443-2751 24/7/365, or visit
www.xltovens.com. The website offers an interactive troubleshooting guide that can further assist
in diagnosing problems.
For repairs or maintenance of the fire suppression system and components, contact the lo-
cal Ansul dealer or XLT for assistance.
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HOOD TROUBLESHOOTING
VFD Control Box - Standard
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MUA Damper Relay
(R1)
MUA Damper Relay
(R2)
MUA Damper Relay
(R3)
Fire Suppression Relay
(R4)
Grounding Block Terminal Strip (TS1)
Terminal Strip (TS2)
Manual Mode
Relay (R5)
Manual Mode
Relay (R6)
Manual Mode
Relay (R7)
Fire Suppression
Relay (R8)
Circuit Breaker
VFD Controller
Manual Mode Switch #1
Oven/hood interface
Manual Mode Switch #2
VFD Control Box (Cover removed)
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