TurboChef NGC (Tornado) User manual

Accelerating the World of Cooking
TurboChef Service Manual
    ()
800.90TURBO
Part Number: NGC-1007 / Revision A, July 23, 2004

IMPORTANT SAFETY INFORMATION - PLEASE READ FIRST
: 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.
This product employs an exposed radiant heating element on the bottom of the cavity. This element is
HOT during operation and will remain at dangerous temperatures after the unit is switched off. NEVER
attempt to touch the element during operation or while the oven is warm.
o
x store or use gasoline or any other flammable vapors or liquids in the vicinity of this or any
other appliance.
The information contained in this manual is important for the proper installation, use and maintenance
of this oven. Adherence to these procedures and instructions will result in satisfactory baking results and
long trouble-free service. Please read this manual carefully and retain it for future reference.
Errors - descriptive, typographic or pictorial - are subject to correction. Specifications are subject to change
without notice.

Important Safety Instructions i
Precautions to Avoid Possible Exposure to Excessive Microwave Energy ii
Grounding Instructions ii
RF Interference Considerations ii
Chapter 1: Installation, Specifications and Maintenance
Specs and Dimensions 1
Dimensions
Construction
Standard Features
Accessories
Certification
Packaging
Power Supply - North America
Delivery and Product Placement 2
Lifting and Placement of the Oven
Restraint Oven Kit
Electrical Specifications 2
Setup and Initial Operation 2
Setup
Programming
Initial Power-Up
Maintenance 3
Chapter 2: Theory of Operation
The Theory of Operation 5
Glossary of Common Operating Terms 6
Chapter 3: Fault Codes
To View Fault Codes 9
Fault Code Definitions 9
Fault Code Table 10
Chapter 4: The Control System
Control System Schematic 11
Control System Component Descriptions 12
Test Function Options 13
Status Indicators 14
Programming 14
User Configurable Options 15
Passwords 16
Control System Panel Parts 17
Control System Trouble Shooting 18
Table of Contents

Chapter 5: The Microwave System
Overview of a Microwave Circuit 21
Monitor Circuit Description 21
Microwave Circuit Theory of Operation 22
Microwave System Parts 22
Microwave System Components 23
Wave Guide Cover Replacement 24
Wave Guide/Wave Guide Cover Parts 25
Wave Guide Replacement and Cleaning 26
High Voltage Transformer & Filament Transformer Replacement 26
Wiring the High Voltage Transformers
Wiring the Filament Transformers
Measuring RF Leakage for Microwave Safety 27
Testing Microwave Components 28
Testing the High Voltage Diode
Checking a Diode
Checking a Capacitor
Checking a Magnetron for Open/Shared Filament
Checking a High Voltage Transformer or Filament Transformer
High Voltage and Filament Transformer Resistance Table 29
Microwave System Trouble Shooting 30
Chapter 6: The Cook Door
Removing/Reinstalling the Cook Door 33
Cook Door Parts 33
Adjusting the Cook Door 34
Adjusting the Primary and Secondary Interlock Switches 34
Primary and Secondary Interlock Switches Adjustments and Parts 35
Door Switch Assembly and Parts 36
Adjusting the Monitor Safety Switch 36
Monitor Safety Switch Parts 37
Cook Door Assembly 38
Cook Door Parts 38
Screw Torque Chart 39
Interlocks Trouble Shooting 40
Chapter 7: The Convection Circuit
Convection System Components 41
Convection Circuit Parts 42
Blower Motor Parts 43
Convection Circuit Trouble Shooting 44
Motor Winding Resistance Table 45

Chapter 8: IR Element and Catalytic Converter
Components 47
IR Element and Catalyst Removal 47
Removing the IR Element
Removing & Installing the Catalytic Converter
Installing a New IR Element
IR Element and Catalytic Converter Parts 48
Chapter 9: Schematic and Schematic Parts
NGC (Tornado) Schematic Inside 49
Schematic Parts 49
Line Voltage Components
Low Voltage Components
Wire Harness Replacement P/N’s
I/O Control Board Item Identification and Test Point Locations 49
Chapter 10: Service Parts and Illustrations
Figure 4: NGC (Tornado) Control System 51
Figure 12: Control System Panel Enclosure and Parts 52
Figure 13: Monitor Circuit - Shown in Failsafe State 53
Figure 15: Microwave System Parts 53
Figure 16: Microwave System Parts 54
Figure 17: Wave Guide Cover/Wave Guide Removal and Replacement 54
Figure 18 & 19: High Voltage Transformer and Filament Wirings 55
Figure 21&22: High Voltage Diode and Magnetron 55
Figure 23: Cook Door Removal and Parts 56
Figure 26: Primary and Secondary Interlocks Adjustment and Parts 56
Figure 27: Door Switch Assembly and Parts 57
Figure 28: Motor Switch Adjustment and Assembly 58
Figure 29: Cook Door Assembly 59
Figure 31: Convection Circuit Block Diagram 60
Figure 32: Convection Circuit Assembly and Parts 61
Figure 33: Blower Motor Parts and Assembly 62
Figure 34: IR Element and Catalytic Converter Parts and Assembly 63
Figure 35: NGC (Tornado) Schematic 64
Figure 36: I/O Control Board and Test Point Locations 64
Figure 37: Covers and Miscellaneous Parts 66

i
INTRODUCTION
IMPORTANT SAFETY INSTRUCTIONS
The following basic safety precautions should be strictly adhered to when using electrical appliances, so as
to reduce the risk of burns, electric shock, fire, injury to persons or exposure to excessive microwave energy.
oRead all instructions before using the appliance.
oRead and follow the Specific Precautions to Avoid Possible Exposure to Excessive Microwave Energy
found on page ii.
oThis appliance must be grounded. Connect only to properly grounded outlet. See Grounding Instructions
found on page ii.
oInstall or locate this appliance only in accordance with the provided installation instructions.
oSome products such as whole eggs and sealed containers - for example: closed glass jars - may explode
and should not be heated in this oven.
oUse this appliance only for its intended use as described in this manual.
oThis appliance should be serviced only by qualified service personnel. Contact the nearest authorized
service facility for examination, repair or adjustment.
oKeep cord away from heated surfaces.
o
x allow children to use this appliance.
o
x  use corrosive chemicals or vapors in this appliance. This type of oven is specifically designed
to heat, cook or dry food. It is not designed for industrial or laboratory use.
o
x operate this appliance if it has a damaged cord or plug, is not working properly, or has been
damaged or dropped. See Power Supply Cord Replacement found on page ii.
o
x  cover or block any openings on the appliance.
o
x store this appliance outdoors.
o
x use this product near water - for example: near a kitchen sink, in a wet basement or near a
swimming pool.
o
x  immerse cord or plug in water.
o
x  let cord hang over edge of table or counter.
o
x use a water jet for cleaning. See the Maintenance section of this manual on page 3 for proper
cleaning procedures.
To reduce the risk of fire in the oven cavity:
oRemove wire twist-ties from paper or plastic bag in the oven.
oIf materials inside the oven should ignite, keep oven door closed, turn oven off and disconnect the power
cord or shut off power at the fuse or circuit breaker panel.
oIf smoke is observed, switch off or unplug the oven. Keep the door closed in order to stifle any flames.
o
x  use the cavity for storage purposes.
o
x  overcook food. Carefully attend the oven if paper, plastic or other combustible materials are
placed inside the oven to facilitate cooking.
o
x leave paper products, cooking utensils or food in the cavity when not in use.
SAVE THESE INSTRUCTIONS

ii INTRODUCTION
PRECAUTIONS TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY
To reduce the risk of exposure to excessive microwave energy:
o
x  attempt to operate this oven with the door open. Open-door operations can result in harmful
exposure to microwave energy. It is important not to defeat or tamper with the safety interlocks.
o
x  place any object between the oven front face and the door or allow soil or cleaner residue to
accumulate on the sealing surfaces.
o
x  operate the oven if it is damaged. It is particularly important that the oven door close properly
and that there is no damage to the door (bent), hinges and latches (broken or loosened), door seals and
sealing surfaces.
o
x  have the oven adjusted or repaired by anyone except a factory authorized service technician.
GROUNDING INSTRUCTIONS
This appliance must be grounded. In the event of an electrical short circuit, grounding reduces the risk of
electric shock by providing an escape wire for the electric current. This appliance is equipped with a cord
that has a grounding wire with a grounding plug. The plug must be plugged into an outlet that is properly
installed and grounded. Consult a qualified electrician or serviceman if uncertain about the ability to follow
grounding instructions or if doubt exists as to whether the appliance is properly grounded.
o
x  use an extension cord. If the power supply cord is too short, have a qualified electrician or
serviceman install an outlet near the appliance.
Power Supply Cord Replacement
If the power supply cord is damaged, it must be replaced by the manufacturer, its service agent or a similarly
qualified person in order to avoid a hazard.
: Improper grounding can result in a risk of electric shock.
RF INTERFACE CONSIDERATIONS
The NGC (Tornado) oven generates radio frequency signals. This device has been tested and was determined
to be in compliance with applicable portions of FCC part 18 requirements and to the protection require-
ments of Council Directive 89/336/EEC on the approximation of the laws of the Member States relating
to electromagnetic compatibility at the time of manufacture. However, some equipment with sensitivity
to signals below these limits may experience interference.
If your equipment experiences interference, the following steps should be considered:
oIncrease the physical separation between this oven and the sensitive equipment.
oIf the sensitive device can be grounded, do so following accepted grounding practices.
oIf battery powered microphones are being affected, insure that the batteries are fully charged.
oKeep sensitive equipment on separate electrical circuits if possible.
o
x  route intercom wires, microphone wires or speaker cables near the oven.
SAVE THESE INSTRUCTIONS

1
Standard Features
oRecirculating airpath with TurboChef
Technologies patented catalytic converter system
oMulti-speed convection blower
oConventional wire baking rack
oIndependently controlled bottom browning
element
oStackable design
oSmart Voltage Sensor Technology
oFactory programmed with up to 128 cooking
programs
oSmart Card for remote programming
oWarranty - 1year parts and labor
Accessories (Additional Charge)
o24” stainless steel oven stand with locking casters
for single units
o17” stainless steel oven stand with locking casters
for stacked units
Certifications
UL, cUL, NSF, FDA, FCC
Packaging
All ovens are packaged in a double-wall corrugated
box with integrated corrugated skids.
SPECS AND DIMENSIONS
Dimensions
  
Height 23” (with 4” legs) 8”
Width 26”15.5”
Depth 25.7”14.7”
28.2” (with handle)
Weight 190 lbs.
 
Back 0”
Sides 2”
  (minimum)
Crated 30”
Uncrated 24”
Construction

o430 stainless steel front, top and sides.
o4” chrome plated adjustable legs
oNickel plated handle
oCool to the touch pull down door

o304 stainless steel line
oFully insulated cooking chamber
oRemovable wire cooking rack with optional platter
oAdjustable lower cooking element
 : NGC (Tornado) Dimensions
INSTALLATION, SPECIFICATIONS AND MAINTENANCE

2INSTALLATION, SPECIFICATIONS AND MAINTENANCE
Power Supply - North America
   
Universal Voltage: 208/240 VAC, 60 Hz,
1 phase
Amperage: Nameplate rating 30 Amp
(3-wire including ground)
Cordset: 10 gauge, 3 conductor,
5 foot cordset
Plug: NEMA 6-30
: The Smart Voltage Sensor Technology does
not compensate for lack of or over voltage situations.
It is the responsibility of the owner to supply voltage
to the unit according to the above specifications.
DELIVERY AND PRODUCT PLACEMENT
Remove oven from carton. Immediately note any
damage and contact shipping company within 24
hours in order to file a claim. TurboChef will not
be responsible for product damaged in shipment.
The carton may be discarded after oven is removed.
: Oven weight is approx. 190 lbs.
Two or more persons are required to lift it.
Lifting and Placement of the Oven
Position one or more persons on either side of the
oven and lift from the bottom. Never lift the oven
from the front and rear. Place the oven on a coun-
tertop surface at least 28 inches deep and capable
of supporting 200 lbs.
Once properly positioned on the counter, plug the
oven into a NEMA 6-30R wall mounted electrical
receptacle. See Electrical Specifications.
Restraint Oven Kit (P/N TC3-0240)
An optional system intended to hinder the oven
from moving forward during use and/or cleaning.
The Restraint Oven Kit will not prevent the oven
from falling off a countertop if the legs are allowed
to slide off the edge or if the oven is intentionally
or forcefully pulled off.
Proper installation instructions are included in the
Restraint Oven Kit, if the operator has ordered one.
If additional help is needed, please call customer
service at 800.90TURBO.
ELECTRICAL SPECIFICATIONS
Operating Voltage 208 VAC/240VAC
Current Draw 30 Amps
Phase 1 Phase
Frequency 60 Hz
Max Input 5990/6675 watts
Microwave Input Power 3500 watts*
*Maximum Independent Input Power
: Never lift the oven by its door
handle. Physical damage to the oven and/or
personal injury may result. The operator must ensure
that the oven is properly placed on the countertop
at all times. TurboChef will not recognize a fallen
oven as a warrantable claim and is not liable for any
injuries that may result.
SETUP AND INITIAL OPERATION
Setup
Once oven is properly positioned on the counter,
remove any packing material and/or any foreign
objects from within the cavity. Install the oven rack
by sliding the rack onto the support shelves.
Programming
The oven comes preprogrammed and is ready to
operate out-of-the-box.
Initial Power-up
To turn the oven On, press the “On” Key next to
the word “On” on the display. The oven will begin
to warm up to its predefined cooking temperature
of 500ºF. This takes approximately 10 minutes.
When the Warm-up Cycle is completed, the oven
will beep and display the “Ready State”. At this
point, the oven is ready to cook.

3
INSTALLATION, SPECIFICATIONS AND MAINTENANCE
DAILY MAINTENANCE FOR THE NGC
The Daily Cleaning Recommendation below will
help in maintaining the NGC (Tornado) oven. Be
sure to use only TurboChef®Oven Cleaner. The use
of any other cleaning products can damage critical
parts and may void warranty on those parts.
Supplies and Equipment
TurboChef®Oven Cleaner, nylon green scrub pad,
cleaning towel
Step 1: Prepare the Oven.
oTurn oven off by pressing the “Back” key.
oThe oven will display “Oven Off-Cooling Down”.
o
x  attempt to clean oven during the cool
down cycle, indicated by “Cooling Down” signal
on display.
oCooling takes approximately 90 minutes.
: The oven operates at 500ºF and may cause
injury if not allowed to cool properly.
Step 2: Remove the Lower Access Panel.
oWipe out any crumbs that have collected.
Step 3: Remove the Wire Rack.
oWash, rinse and sanitize the wire rack.
: Be sure oven interior is cool prior to
removing the wire rack.
Step 4: Lift Bottom Element.
oBe sure the bottom element is cool prior to lifting.
: The oven element operates at 1000ºF and
may cause injury if not allowed to cool properly.
Step 5: Remove Particles and Spray Oven Interior
with TurboChef®Oven Cleaner.
oUsing a damp towel, remove any large particles
from the oven.
oIf stubborn stain is present, sparingly spray
TurboChef®Oven Cleaner into the cavity and
on the door.
oAllow cleaner to penetrate for five (5) minutes.
oNever saturate the bottom of the oven with
water or oven cleaner.
Step 6: Clean Oven Interior.
oUsing a nylon green scrub pad, clean the oven
door and cavity.
: Do not apply pressure to white
Wave Guide Caps. Breaking will result in a
non-warranty service call.
Step 7: Wipe Out Oven Interior.
oWipe oven door and cavity clean using a
damp towel.
oWipe the element with a clean damp towel.
10
9
876
1 2 3 4 5

Step 8: Clean Area where Lower Access Panel
is Located.
oWipe the area on the outside of the oven where
the lower access panel is located.
o
x  spray any chemical in this area.
Step 9: Lower the Bottom Element and Replace the
Wire Rack and Lower Access Panel.
Step 10: Clean Oven Exterior.
oWipe the oven exterior with a clean, damp towel.
oOven is ready to turn on.
DO’S AND DO NOT’S
DO:
oEnsure the oven is cleaned daily.
oUse only TurboChef®Oven Cleaner.
oRemove items from the oven as soon as they
are cooked.
oUse only microwave-safe TurboChef approved
cooking accessories in the oven.
oReview cooking instructions to ensure oven set-
tings are correct for corresponding products.
oKeep the TurboChef Installation Guide for
future reference.
oCall TurboChef immediately if Wave Guide
Caps are broken.
DO NOT:
o
xLift oven by handle.
o
xSlam or mishandle the oven door.
o
xPlace foil or metal objects of any kind in the oven.
o
xOperate the oven without food in the cook
chamber.
o
xFrequently open and close the door to check
the product.
o
xCook items wrapped in plastic or any type of
cling film.
o
xPut products in the oven until ready to cook.
o
xUse cleaning agents that are not approved for
the oven.
o
xAllow any cleaning solution or water to remain
on the bottom of the cooking chamber after
cleaning or at any other time.
o
xPlace excessive weight on top of the oven.
4INSTALLATION, SPECIFICATIONS AND MAINTENANCE

5
THEORY OF OPERATION
THE THEORY OF OPERATION
The TurboChef NGC (Tornado) oven utilizes three
independent heat transfer mechanisms in order to
rapidly cook food.
The systems are as follows:
oConvection
oInfrared energy
oMicrowave energy
By combining these mechanisms along with the
ability to control each mechanism independently,
the NGC (Tornado) oven is able to reduce the cook
time of most foods by 70-90 percent.
Figure 2 below represents the oven’s different systems
and the critical components of each system. Should
a problem arise with any of the components listed
below, please turn to the appropriate section within
this manual for further instructions.
For the purpose of this manual, each independent
heat transfer mechanism is individually identified.
For instance, if an oven is experiencing difficulties
browning the food, focus on the Convection Circuit
and/or the Infrared Circuit, versus the Microwave
Circuit. Focus on the Microwave System if an oven
is browning the food but not heating the food.
Chapter 4
CONTROL SYSTEM
I/O Control Board
Keypad
Display
Mechanical Relays
SS Relays
Chapter 5
MICROWAVE SYSTEM
Magnetrons
High Voltage Transformers
Filament Transformers
High Voltage Capacitors
High Voltage Diodes
Fuse
Chapter 7
CONVECTION SYSTEM
Convection Heater
Blower Controller
Convection Blower
Catalytic Converter
Hi-Limit Thermostat
Chapter 8
BOTTOM IR AND CCV
Bottom Infrared Element
Mechanical Relays
SS Relays
 : NGC (Tornado) Systems and Critical Components

6THEORY OF OPERATION
GLOSSARY OF COMMON OPERATING TERMS
Off State
All the oven’s control systems are off and the Cook Chamber Temperature is below 150ºF.
Cool Down
A subset of the Off State. During Cool Down the oven will circulate the main convection blower until
the Cook Chamber Temperature is below 150ºF.
Ready State
Refers to an oven that has successfully warmed-up to the predefined Set-Temperature. At this point the
oven control is ready to receive cook commands via the Keypad.
Set-Temperature (TSET)
A predefined temperature at which the oven cooks.
Cook Chamber Temperature (TCC)
The actual temperature registered by the Cook Chamber Thermocouple.
Edit Mode
The mode which enables the user to change stored or predefined Recipes and the Set-Temperature.
Warm-Up
The mode when the oven is warming itself to the Set-Temperature.
Idle Mode
Similar to the Ready State. In this mode, the oven’s control may cycle the blower or heaters in order to
maintain the Set-Temperature.
Cook Cycle
A period of operation as defined by a Recipe.
Test Mode
A special diagnostic mode that enables the service technician to turn on and off all oven systems
independent of one another.
Keypad
The primary interface for the operator.
Display
Displays all visual information to the operator.
Self-Test (STEST)
A special diagnostic function that tests all critical subsystems to determine their operational state.
Recipe
A set of user defined Events that determine a Cook Cycle.

7
THEORY OF OPERATION
Events
A single operational element that is a part of a Recipe. Each Recipe may have up to six Events depending
on programming. Each Event lasts a percentage of the Total Cook Time and can be set between 0 and
100% of the Total Cook Time. The sum of all the Event Percent (%) Times must equal 100%.
Total Cook Time
The total duration of a Recipe.
Percentage (%) Time
An event subset that specifies the duration of the Event.
Percentage (%) Air
An event subset that specifies the relative amount of impingement airflow (speed of convection motor)
during the Event. Valid between 10 and 100%.
: Maximum 100% = 7100 RPM Blower Motor Speed. Blower Motor Speed scale is linear.
Percentage (%) Microwave (MW)
An event subset specifying the microwave cycle (on time) during the Event. Valid between 0 and 100%.
Fault Code
A code assigned to an Event that the Control considers to be a failure. Upon discovering a Fault, the
Control will display the Fault Code and a brief description of the failure. The Control will also increment
the Fault Code Counter.
Error Message
A message that is displayed when an unusual event occurs. The Control will display the Error Message
only when it occurs. Error Messages are not logged in the Fault Code Counter.

9
The NGC (Tornado) oven has the ability to continually
monitor and log various fault conditions. Some fault
conditions will terminate Cook Cycles, while others
will not. Please refer to the Fault Code Table on
page 10 for more detailed information.
When a fault is detected, the Fault Code Counter
will increment. However, if the fault is subsequently
cleared by some action, whether service related or
not, the Fault Code Counter will not decrement.
TO VIEW FAULT CODES
To view the Fault Log, press the “4” and “6” Keys
simultaneously while the oven is in the Off State.
The oven will display all faults logged. Figure 3.
Each Fault Log will log up 255 instances before
rolling back to zero. Press the “0” Key to reset the
Fault Code Counter.
: The Fault Log also displays the Cook
Counter, which will log up to 65,535 Cook Cycles.
In order for the Control to log a Cook Cycle, the
oven must complete the first Event of any given
Recipe. If a Recipe only has one (1) Event, the oven
must complete the entire Cook Cycle in order to
count the Cook Cycle.
FAULT CODE DEFINITIONS
F1: Blower Running Status Bad
Fault is displayed when the Blower Controller
indicates no running status.
The Motor and Motor Controller state is monitored
continuously in all Modes with special handling in
the Self-Test and Test Mode. If a fault is detected,
the Control will bounce the oven into the Off State.
Upon turning the oven On, the Control will attempt
to restart the Motor. If the restart is successful the
fault indication will be cleared. The fault is also
cleared at the onset of cooking or when the blower
is tested in the Test Mode.
F2: Cook Temperature Low
Fault is displayed if the Cook Chamber Temperature
is more than 84ºF below the Set Temperature after
five (5) seconds into a Cook Cycle.
The fault is cleared at the onset of cooking if the
Cook Chamber Temperature is within 84ºF of the
Set Temperature or when the heater is tested in the
Test Mode.
F3: Magnetron Current Low
Fault is displayed when the Current Transformer
(CT) on the I/O Control Board does not detect
enough current. The Fault is monitored when the
microwave is on during a Cook Cycle or Self-Test.
The fault is cleared at the onset of a Cook Cycle if
the CT detects current or when the magnetron is
successfully energized in the Test Mode.
F4: Door Monitor Defective
Fault is displayed when the Control detects that the
Monitor Interlock Switch unlatches before both the
Primary and Secondary Interlock Switches during a
Cook Cycle.
In addition this fault will blow the F3 Fuse if the
microwave high voltage system is energized when
the fault occurs. The fault is cleared only when the
oven is turned Off and On.
COOK COUNT
F1 BLOWER
F2 LOW TEMP
F3 MAG CURR
F4 MONITOR
F5 MAG TEMP
F6 TEMP
S/N XXXXXX
NGCVXXXX XXXXXX
0
0
0
0
0
0
0
 : Fault Display
FAULT CODES

10 FAULT CODES
: Door Interlock Switches are in parallel. See
Figure 35, on the inside of page 49. The fault is
monitored during a Cook Cycle or Self-Test, when
the Microwave is on.
F5: Magnetron Over Temperature
Fault is displayed when the Thermostat on either
Magnetron is “Open”.
The fault is cleared at the onset of a Cook Cycle if
the Thermostat is closed or when the Magnetron is
successfully tested in the Test Mode.
F6: EC (Electrical Compartment) Temperature High
Fault is displayed when the EC Thermocouple
exceeds 158ºF and is monitored once per minute.
The fault is cleared when the EC Thermocouples
temperature is below the indicated limit.
F7: Thermocouple Open
Fault is displayed when the Control detects that
either the IR or CC Thermocouple is “Open”.
o999ºF indicates the CC Thermocouple is “Open”.
o1999ºF indicates the IR Thermocouple is “Open”.
Fault is cleared when the control detects continuity
on the open Thermocouple Circuit.
F8: Heat Low
An Error Message (not a Fault Code) displayed
during Warm-up or Self-Test if the Cook Chamber
Temperature (TCC) fails to rise 14ºF within thirty
(30) seconds.
FAULT CODE AND DESCRIPTION WHEN ACTIVE REFER TO
F1: Blower Running Status Bad
F2: Cook Temperature Low
F3: Magnetron Current Low
F4: Door Monitor Defective
F5: Magnetron Over Temperature
F6: EC Temperature High
F7: Thermocouple Open
F8: Heat Low
FAULT CODE TABLE
Fault Codes are listed in order of hierarchy. For example: If during cooking the oven experiences an F1
and F2 Fault, the oven will only report a F1 Fault since the software will halt all actions upon discovering
the F1 Fault. F7 and F8 Faults are displayed on the primary screen and are not displayed or counted in
the Fault Log.
: All Fault Codes listed in Bold will terminate a Cook Cycle upon discovery. Any fault occurring
in a Cook Cycle will be logged in the Fault Code Counter.
Warm - up
X
X
X
X
Idle Mode
X
X
X
Cook Mode
X
X
X
X
X
X
X
Self-Test
X
X
X
X
X
Page 19
Page 20
Page 30
Page 36
Page 24
Page 12
Page 18
Page 44

11
THE CONTROL SYSTEM
The Control System is comprised of the components
that signal, sense, command and switch the oven’s
various components. Figure 4 shows a functional
diagram of all the components that make up the
Control System.
: The part numbers for each component are
given within the parentheses in addition to being
included with the descriptions for each part on the
following page.
VOLT
(100783)
IR THERMOCUOPLE
EC THERMOCUOPLE
CC THERMOCUOPLE
A(-)
C(+)
A(-)
C(+)
A(-)
C(+)
VOLTAGE INPUT
COMMON
12 14
KEYPAD
(NGC-1110)
VDF
DISPLAY
(100505)
COMMON
SECONDARY SWITCH
INTERLOCK
PRIMARY SWITCH
INTERLOCK
PRIMARY SWITCH
(102012)
(102012)
SECONDARY SWITCH
12 25 26 12 25 26 12 25 26 12 25 26
12 14
12 14
12 14
IR ELEMENT COMMAND
CONVECTION HEATER COMMAND
+24 VDC
+24 VDC
MONITOR
INTERLOCK
MONITOR SWITCH
(102012)
DUAL
SSR
RELAY
(101284)
K5 K4
3(+)3(+)4(-)
4(-)
+24 VDC
+24 VDC
COMMON
K6
MECH
RELAY
(101272)
K3
MECH
RELAY
(101271)
K2
MECH
RELAY
(101271)
K1
MECH
RELAY
(101271)
+24 VDC - + 24 VDC - + 24 VDC - + 24 VDC -
I/O
CONTROL
BOARD
(NGC-1008)
24 VDC
POWER SUPPLY
(101206)
L
N
+V
-V
1
2
3
1
2
3
4
1
2
3
4
5
6
200-240
VAC IN
240 VAC
3 PHASE
OUT
BMSC
(100443)
0-10V
I/O COM
I/O COM
ENABLE
STATUE OK
I/O COM
SPD
CMD
NC C
NO
NC C
NO
NC C
NO
 : NGC (Tornado) Control System

12 THE CONTROL SYSTEM
CONTROL SYSTEM COMPONENT DESCRIPTIONS
24 VDC Power Supply (P/N 101206)
24 VDC Output at 40 Watts. Supplies control
voltage for I/O Control Board, 24 VDC Mechanical
Relays and Solid State Relays.
K1 Mechanical Relay (P/N 101271)
240 VAC, 30 Amp, Double Pole, Double Throw, 24
VDC Relay Coil. Switches power to the Magnetron
Filament Transformers.
K2 Mechanical Relay (P/N 101271)
240 VAC, 30 Amp, Double Pole, Double Throw, 24
VDC Relay Coil. Switches power to the Magnetron
High Voltage Transformers.
K3 Mechanical Relay (P/N 101271)
240 VAC, 30 Amp, Double Pole, Double Throw, 24
VDC Relay Coil. Safety Interlock device designed to
short L1 and L2 if the Monitor Switch opens before
the Primary and Secondary Interlock Switches.
K4/K5 SSR (P/N 101284)
240 VAC, Dual 40 Amp Solid State Relay. K4
(right) controls the Convection Heater and K5
(left) controls the IR Element.
K6 Mechanical Relay (P/N 101272)
240 VAC, 30 Amp, Three Pole, Double Throw, 24
VDC Relay Coil. Responsible for switching between
the 208VAC and 240VAC taps on the High
Voltage and Filament Transformers.
Interlock Switches (P/N 102012 for all three)
Primary, Secondary and Monitor Interlock Switches.
Switches must be actuated by the Cook Door in the
following order: M-S/P. When the Cook Door
opens, the order is reversed: P/S-M.
IR Thermocouple (IR Element)
Type K Thermocouple. Thermocouple is embedded
in the IR Element. The Thermocouple measures
the internal/sheath temperature of the IR Element.
Valid IR Set points are between 500ºF and 1200ºF.
The display indicates 1999ºF, if the Thermocouple
is “Open”.
EC Thermocouple (P/N 700-1179)
Type K Thermocouple. Thermocouple measures the
temperature of the Electrical Compartment. If the
temperature within the Electrical Compartment is
above 158ºF, the Control displays “F6 - EC Temp”.
CC Thermocouple (P/N NGC-1140)
Type K Thermocouple. Thermocouple measures
the temperature of the re-circulating impingement
airflow. Valid IR Set points are 450-540ºF. If the
display indicates 999ºF, the Thermocouple is Open.
BMSC (P/N 100443)
A proprietary Brushless DC Motor Controller
designed solely to operate the Convection Motor.
VDF Display (P/N 100505)
Vacuum Fluorescent Display.
Keypad (P/N NGC-1110)
3x8 Matrix Membrane Switch. Keypad is connected
to the Control via a 14 Pin Flat Cable.
Voltage Sense Module (P/N 100783)
Proprietary device designed to measure incoming
line voltage and switch between 208 and 240 VAC
operation. The device only measures and configures
the oven when the oven is switched from the Off
State to the On State.
TEST MODE
The Test Mode allows the service technician to
operate the oven’s subsystems individually. It also
allows the operator to configure various presets.
To enter the Test Mode:
1. Press the “Back” Key until the display is in the
Off State.
2. Press the “Back” and “Enter” Key simultaneously.
3. Enter the access code: 9-4-2-8 when prompted
and press “Enter”.
The “Test” Screen displays the Software Version,
Cook Chamber and IR Element Temperature at the
top of the screen. The Control also displays the

13
THE CONTROL SYSTEM
first of two (2) pages of the test function options
(Figure 5). To display the second page (Figure 6),
press either the “Down or Up Arrow” Key. To test a
component or sub-system, press the corresponding
Soft Key.
TEST FUNCTION OPTIONS
Blower Speed
The “Blower” Key increments the Blower Speed in
10% steps. When the Blower Speed is 100%, the
next press sets the speed to 0%.
Electronic Compartment Temperature
The “ºELEC” Key displays the temperature inside
the electronic enclosure.
Self-Test Function
The “STEST” Key initiates the Self-Test function
to test all major components of the oven. To run the
Self-Test, press the corresponding Soft Key once.
Press the “Back” Key to return to the Idle Mode.
Heater Test
The “Heater” Key turns the heater On or Off. If
the heaters are On, pressing the corresponding Soft
Key turns the heaters Off. If the heaters are Off
pressing the “Heater” Key turns the heaters On. If
the Blower Speed is 0, the Blower Speed is set to
the Idle Airflow.
Magnetron
The “MGTRON” Key is a press and hold key to
test the Magnetron. If the Magnetron Filaments are
Off when the “MAG” Key is pressed, the message
“MAG Warming Up” is displayed. After a five (5)
second delay or if the filaments are already On,
“MAG Power On” is displayed. The Magnetron
should operate at this point. Once the “MGTRON”
Key is released, the high voltage supply is switched
Off to the Magnetron and the Magnetron will stop
radiating; however, the power is still supplied to the
Magnetron Filaments and Magnetron Cooling Fan
for an extra three (3) minutes.
Diagnostic Display
The “DIAG” Key turns On or Off the Diagnostic
Display feature. This feature adds temperature
displays to the “Menu Group” Screens.
While cooking, the Cook Cycle parameters are
displayed when diagnostics are enabled.
In addition, the Status Indicators are displayed on
the bottom of the screen. When a Status Indicator
is highlighted/backlit the corresponding system
associated with that Status Indicator is Off. For
example: Wwould indicate that the Microwave
System is Off.
The Status Indicator section on the following page
offers a more detailed description of each indicator.
CC 810F
TEST NGC VXXXX
IR 5000F
BLOWER HEATER
FAULTS MGTRON
STEST IR ELE
PSM A
th Wi
CC 810F
TEST NGC VXXXX
IR 5000F
DIAG 0ELEC
CCC F/C
PIN IR SI
PSM A
thWi
 : Test Mode - Screen 1  : Test Mode - Screen 2

14 THE CONTROL SYSTEM
Faults
Pressing the “Faults” Soft Key will display all the
accumulated faults in the Fault Log. For more
information, see page 9.
F/C
Changes how the oven’s temperature units are dis-
played. The F/C Key alternately selects Fahrenheit
or Celsius.
CCC
Displays the total number of accumulated Cook
Counts for all Recipes.
PIN
Allows the operator to select a new Access Number
for entering the Test and Edit Modes.
IR ELE
Pressing the “IR ELE” Key will turn On the IR
Element. When pressed, the Control will display
“IR Element On”. To turn the IR Element Off,
push the “IR ELE” Key an additional time.
IR SI
This is a factory setting and should never be altered.
Consult the factory before changing this value.
STATUS INDICATORS
See Figures 5 and 6 on page 13.
PPrimary Switch – closed or open
SSecondary Switch – closed or open
M Monitor Switch – closed or open
t Magnetron Thermostats – closed or open
h Main Convection Heater – off or on
i IR Element – off or on
A Blower Motor Controller – enabled or
disabled
W Microwave Current – Less than or greater
than 7 Amps*
* Microwave (MW) Status Indicator is not
highlighted/backlit when the current is more
than 7Amps.
The Status Indicators are displayed at the bottom
of the display screen when the oven is in the Test
and DIAG Mode. Refer to Figures 5and 6.
If a Status Indicator is highlighted/backlit the item
or component is in an un-energized or Off State.
Conversely, if a Status Indicator is not highlighted,
the component is energized or in the On State.
PROGRAMMING
Edit Mode
The Edit Mode enables the operator to alter Recipes
and the Cook Chamber Temperature (TCC).
To access the Edit Mode:
1. Press the “Up and Down Arrow” Keys on the
Keypad simultaneously.
2. When prompted, enter the Access Code “9” and
then press “Enter”.
Changing the Cook Chamber Temperature
The first screen in Edit Mode allows you to change
the Cook Chamber Temperature (TCC) by pressing
the “Up and Down Arrow” Keys. The operator
may adjust the temperature between 450-540ºFin
10ºFincrements. Once you have selected the desired
temperature, press the “Enter” Key to set TCC.
Altering a Recipe
The NGC (Tornado) oven control has 128 unique
Recipes available for the operator. The display shows
two (2) pages each with eight (8) Recipe Groups.
Each Recipe Group contains eight (8) Subgroups
or Recipes. See Figures 7and 8.
To alter a Recipe:
1. Enter the Edit Mode as described earlier.
2. Enter the Access Code “9” and set TCC. The
screen displays the first set of eight (8) Recipe
Groups. To access the second set of eight (8)
Recipe Groups, press either the “Up or Down
Arrow” Key.