TurboChef NGC-1007 User manual

Accelerating the World of Cooking
TurboChef Service Manual
FOR THE TURBOCHEF NGC (TORNADO) OVEN
800.90TURBO
Part Number: NGC-1007 / Revision D / September 2007

For further information call:
800.90TURBO
+1 214.379.6000
Accelerating the World of Cooking

IMPORTANT SAFETY INFORMATION - PLEASE READ FIRST
WARNING: Improper installation, adjustment, alteration, service, or maintenance can cause property
damage, injury, or death. Thoroughly read the installation, operating, and maintenance instructions
before installing or servicing this equipment.
This product employs an exposed radiant heating element in 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, while the oven is warm, or while the oven is cooling down.

xDO NOT store flammable vapors or liquids (such as gasoline) 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 help
prevent maintenance. 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
General Safety Information i
Reducing Fire Risk i
Precautions to be Observed Before and During Servicing to Avoid Possible
Exposure to Excessive Microwave Energy ii
Grounding Instructions ii
Power Cord Replacement ii
RF Interference Considerations ii
Chapter 1: Installation, Specifications and Maintenance
Specs and Dimensions 1
Dimensions 1
Construction 1
Standard Features 1
Certifications 1
Packaging 1
Power Supply (Domestic and Intl Electrical Specifications) 1-2
Power Input 2
Delivery and Product Placement 2
Lifting and Placing the Oven 2
Built-In Installation 2
Installation Near Open Heat Source 3
Oven Restraint Kit 4
Setup and Initial Operation 4
Setup 4
Stacking 4
Programming 4
Initial Power-Up 4
Maintenance 5
Chapter 2: Theory of Operation
Theory of Operation 7
Glossary of Common Operating Terms 8
Chapter 3: Fault Codes
To View Fault Codes 11
Fault Code Definitions 11
Fault Code Table 12
Chapter 4: The Control System
Control System Schematic 13
Control System Component Descriptions 14
Test Mode 14
Test Function Options 15
Status Indicators 16
Table of Contents

Oven Options 18
User Configurable Options - Enable/Disable Codes 19
User Configurable Options - Access Codes 19
Control System Panel Parts 20
Control System Troubleshooting 21
Chapter 5: The Microwave System
Voltage Doubler Circuit Description 25
Monitor Circuit Description 25
Voltage Doubler Theory of Operation 26
Microwave System Parts 26
Microwave System Components 28
Wave Guide Cover Replacement 29
Wave Guide/Wave Guide Cover Parts 30
Wave Guide Replacement 30
High Voltage and Filament Transformer Replacement 30
Wiring the High Voltage Transformers 30
Wiring the Filament Transformers 31
Measuring RF Leakage for Microwave Safety 31
How to Test Microwave Components 32
Testing the High Voltage Diode 32
How to Check a Diode 32
How to Check a Capacitor 33
How to Check a Magnetron for Open/Shorted Filament 33
How to Check a High Voltage Transformer or Filament Transformer 33
High Voltage and Filament Transformer Resistance Table 33
Microwave System Troubleshooting 34
Chapter 6: The Oven Door
Removing/Reinstalling the Oven Door 37
Oven Door Parts 37
Adjusting the Oven Door 38
Preparing the Oven for Switch Adjustment 38
Oven Burn-In Procedure 38
Adjusting the Primary and Secondary Interlock Switches - Old Switch Setup 38
Primary and Secondary Interlock Switch Adjustments and Parts 39
Door Switch Assembly and Parts 40
Adjusting the Monitor Safety Switch - Old Switch Setup 40
Monitor Safety Switch Parts 40
Adjusting the Primary Interlock Switch - New Switch Setup 42
Primary Switch Adjustment and Parts 42
Adjusting the Secondary and Monitor Interlock Switches - New Switch Setup 43
Secondary and Monitor Safety Switch Parts 43
Oven Door Assembly 44
Oven Door Parts 44
Screw Torque Chart 45
Interlock Switch Troubleshooting 46

Chapter 7: The Convection Circuit
Convection Circuit Components 47
Convection Circuit/Blower Motor Parts 48
Convection Circuit Troubleshooting 49
Motor Winding Resistances Table 50
Chapter 8: IR Element and Catalytic Converter
Components 51
IR Element and Catalyst Removal 51
Removing the IR Element 51
Removing & Installing the Catalytic Converter 52
Installing a New IR Element 52
IR Element and Catalytic Converter Parts 52
Chapter 9: Schematics and Schematic Components
Schematic Parts 53
Line Voltage Components 53
Low Voltage Components 53
Wire Harness Replacement P/N’s 53
I/O Control Board Item Identification and Test Point Locations 53
Schematic - I/O Board 54
Oven Schematics 55 - 63
Chapter 10: Service Parts and Illustrations
Figure 7: NGC (Tornado) Control System 65
Figure 17: Control System Panel Enclosure and Parts 66
Figure 18: Monitor Circuit - Shown in Failsafe State 67
Figure 20: Microwave System Parts 67
Figure 21: Microwave System Parts 68
Figure 22: Wave Guide Cover/Wave Guide Removal and Replacement 68
Figure 24 & 25: High Voltage Diode and Magnetron 69
Figure 26: Oven Door Removal and Parts 69
Figure 29: Primary and Secondary Adjustment and Parts - Old Switch Setup 70
Figure 30: Door Switch Assembly and Parts 70
Figure 31: Motor Switch Adjustment and Assembly - Old Switch Setup 71
Figure 32: Primary Interlock Adjustment and Parts - New Switch Setup 71
Figure 33 & 34: Secondary and Monitor Adj. and Assy. - New Switch Setup 72
Figure 35: Oven Door Assembly 73
Figure 37: Convection Circuit Block Diagram 74
Figure 38: Convection Circuit Assembly and Parts 75
Figure 39: IR Element and Catalytic Converter Parts and Assembly 76
Figure 46: Covers and Miscellaneous Parts - Non-SBK Ovens 77
Figure 47: Covers and Miscellaneous Parts - SBK Ovens 78
Chapter 11: Comprehensive Part List
Comprehensive Part List 79

i
INTRODUCTION
IMPORTANT SAFETY INSTRUCTIONS
Strictly adhere to the following safety precautions to reduce the risk of:
Burns
Electric shock
Fire
Injury
Damage to oven or property near oven
Exposure to excessive microwave energy
GENERAL SAFETY INFORMATION
Read all instructions before using the appliance.
Install or locate this appliance only in accordance with the provided installation instructions.
Some products such as whole eggs and sealed containers (e.g., closed glass jars) may explode and should not be
heated in this oven.
Use this appliance only for its intended use as described in this manual.
This appliance should be serviced only by qualified service personnel. Contact the nearest authorized service
facility for examination, repair, or adjustment.
Keep cord away from heated surfaces.

xDO NOT allow children to use this appliance.

xDO NOT use corrosive chemicals or vapors in this appliance - it is not designed for industrial or laboratory use.

xDO NOT operate this appliance if it has a damaged cord or plug, is not working properly, or has been damaged
or dropped. See POWER CORD REPLACEMENT, page ii.

xDO NOT cover or block any openings on the appliance.

xDO NOT store this appliance outdoors.

xDO NOT use this product near water (e.g., near a kitchen sink, in a wet basement, near a swimming pool).

xDO NOT immerse cord or plug in water.

xDO NOT let cord hang over the edge of table or counter.

xDO NOT use a water jet for cleaning. See the maintenance section of this manual on page 5 for proper cleaning
procedures.
REDUCING FIRE RISK
Remove wire twist-ties from paper or plastic bags used to facilitate cooking in the oven.
If materials inside the oven ignite,
- Keep oven door closed
- Turn oven off
- Disconnect the power cord or shut off power at the fuse or circuit breaker panel
If smoke is observed, switch off or unplug the oven. Keep the door closed to stifle any flames.

xDO NOT use the cook cavity for storage purposes.

xDO NOT overcook food. Carefully attend the oven if paper, plastic, or other combustible materials are placed
inside the oven to facilitate cooking.

xDO NOT leave paper products, cooking utensils, or food in the cavity when not in use.
SAVE THESE INSTRUCTIONS

ii INTRODUCTION
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO
EXCESSIVE MICROWAVE ENERGY
(a) DO NOT operate or allow the oven to be operated with the door open.
(b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other
microwave source, and make repairs as necessary: (1) interlock operation, (2) proper door closing,
(3) seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or loosening of hinges
and latches, (5) evidence of dropping or abuse.
(c) Before turning on microwave power for any service test or inspection within the microwave
generating compartments, check the magnetron, wave guide or transmission line, and cavity for
proper alignment, integrity, and connections.
(d) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave
generation and transmission systems shall be repaired, replaced, or adjusted by procedures described
in this manual before the oven is released to the owner.
(e) A microwave leakage check to verify compliance with the Federal performance standard should be
performed on each oven prior to release to the owner.
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 oven is equipped with a cord that
has a grounding wire with a grounding plug, which 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 ground-
ing instructions or if doubt exists as to whether the appliance is properly grounded.

xDO NOT use an extension cord. If the power cord is too short, have a qualified electrician or service-
man install an outlet near the appliance.
WARNING: Improper grounding can result in risk of electric shock.
POWER CORD REPLACEMENT
If the power cord is damaged, it must be replaced by the manufacturer, its service agent, or a similarly quali-
fied person.
RF INTERFERENCE 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:
Increase the physical separation between this oven and the sensitive equipment.
If the sensitive device can be grounded, do so following accepted grounding practices.
If battery-powered microphones are being affected, ensure that the batteries are fully charged.
Keep sensitive equipment on separate electrical circuits if possible.
Route intercom wires, microphone wires, speaker cables, etc. away from the oven.

Installation, Specifications,
and Maintenance

Standard Features
Recirculating airpath with patented catalytic converter
system
Multi-speed convection blower
Independently-controlled bottom browning element
Stackable design
Smart Voltage Sensor Technology (North America only)
Factory-programmed, customizable menu settings
Smart Card for remote programming
Warranty - 1year parts and labor
Certifications
UL, cUL, NSF, FDA, FCC, TÜV, CE
UL KNLZ Ventless Certification - This product conforms
to the ventilation recommendations set forth by NFPA96
using EPA202 test method.
Packaging
All ovens are packaged in a double-wall corrugated box
banded to a wooden skid.
Power Supply - North America
SMART VOLTAGE SENSOR TECHNOLOGY
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
1
SPECS AND DIMENSIONS
Dimensions
EXTERIOR COOK CAVITY
Height 19” (483 mm) 8” (203 mm)
with legs 23” (584 mm)
Width 26” (660 mm) 15.5” (394 mm)
Depth 25.7” (653 mm) 14.7” (373 mm)
with handle 28.2” (716 mm)
Weight 190 lbs. (86 kg)
WALL CLEARANCE
Back 0” (0 mm) unless built-in (page 2)
Sides 2” (51 mm)
ENTRY CLEARANCE (minimum)
Crated 31.5” (800 mm)
Uncrated 28.7” (729 mm)
Construction
EXTERIOR
430 stainless steel front, top and sides.
4” (102 mm) adjustable legs
Cool to the touch handle
INTERIOR
304 stainless steel line
Fully insulated cooking chamber
Removable assorted cooking surfaces
Independently-controlled lower cooking element
FIGURE 1: NGC (Tornado) Dimensions
INSTALLATION, SPECIFICATIONS, AND MAINTENANCE

2INSTALLATION, SPECIFICATIONS, AND MAINTENANCE
NOTE: The Smart Voltage Sensor Technology does
not compensate for lack of voltage or over-voltage
situations. It is the responsibility of the owner to
supply voltage to the unit according to the follow-
ing specifications.
Power Supply - Europe, Asia-Pacific
NGC EW (3-phase)
Voltage: 400 VAC, 50 Hz, Wye, 5-
wire (3L + N + Ground)
Circuit Breaker: Type D, min. 20 Amps
NGC ED (3-phase)
Universal Voltage: 230 VAC, 50 Hz, Delta, 4-
wire (3L + Ground)
Circuit Breaker: Type D, min. 30 Amps
NGC UK (1-phase)
Voltage: 230 VAC, 50 Hz, 3-wire
(2L + Ground)
Circuit Breaker: Type D, min. 30 Amps
Power Supply - Latin America
NGC BK (1-phase)
Voltage: 220 VAC, 60 Hz, 3-wire
(2L + Ground)
Circuit Breaker: Type D, min. 30 Amps
Power Supply - Japan
NGC JD (3-phase)
Voltage: 200 VAC, 50/60 Hz, Delta,
4-wire (3L + Ground)
Circuit Breaker: Type D, min. 30 Amps
NGC JK (1-phase)
Voltage: 200 VAC, 50/60 Hz, 3-wire
(2L + Ground)
Circuit Breaker: Type D, min. 30 Amps
Power Supply - South Korea
NGC KW (3-phase)
Voltage: 400 VAC, 60 Hz, Wye, 5-
wire (3L + N + Ground)
Circuit Breaker: Type D, min. 20 Amps
POWER INPUT
Heaters Input Power (NA) 5990/6675 watts
Heaters Input Power (Intl) 6300 watts
Microwave Input Power 3500 watts*
*Maximum Independent Input Power
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 is not
responsible if the product is damaged in shipment.
Remove all literature and accessories from the carton.
NOTE: Thoroughly check the carton before discarding.
WARNING: Oven weight is approx. 190 lbs.
(86 kg) Two or more persons are required to
lift it.
Lifting and Placing 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 counter-
top surface at least 28” (711 mm) deep and capable of
supporting 200 lbs (91 kg).
Once properly positioned on the counter, plug the
oven into wall-mounted electrical receptacle. See
page ii for grounding instructions.
WARNING: 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.
Built-In Installation (Figure 2)
TurboChef ovens are designed to be installed on a
countertop or table. They are not intended for built-
in or enclosed installation.
“Built-in or enclosed installation” is defined as
installing an oven in any structure that surrounds the
oven by five sides (i.e., top/rear/side panels and base).

If installation must be “built in,” the operator must
ensure the following:
Minimum of 300 cfm (8.5 cmm) of supplement flow
within the cabinet.
Minimum clearances of 2" (51 mm) to every surface.
In addition, the operator will be responsible for com-
pensating any extra time required to service the prod-
uct due to removing the product for serviceability.
Installation Near Open Heat Source (Figure 3)
When placing a TurboChef oven near an open heat
source, strictly adhere to the following:
Verify oven location has a minimum 6" (152 mm)
clearance on top and minimum 2" (51 mm) of
clearance on each side.
If the oven is being placed near a grill or stove,
there must be a divider between the oven and the
open heat source, with a minimum of 6" (152 mm)
between the oven and the divider.
If the oven is being placed near a fryer, there must
be a divider between the oven and fryer, with a
minimum of 12" (305 mm) between the oven and
the divider.
The height of the divider must be greater than or
equal to the height of the oven (23"/584 mm).
FIGURE 2: Built-in Installation Specs
FIGURE 3: Open Heat Source Installation Specs
INSTALLATION, SPECIFICATIONS, AND MAINTENANCE 3
(102 mm)

4
Oven Restraint Kit (TC3-0242 KIT)
The Oven Restraint Kit is an optional system that
helps prevent the oven from moving forward during
use and/or cleaning. It 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 with the
kit. for additional information, please call customer
service at 800.90TURBO / +1 214.379.6000.
SETUP AND INITIAL OPERATION
Setup
Once the oven is properly positioned on the counter,
remove any packing material and/or any foreign
objects from within the cavity. Install the oven rack/
cooking surface.
Stacking
1. Ensure the surface that will hold the stacked
ovens can support at least 400 lbs (181 kg).
2. Allow ovens adequate time to cool and unplug them
3. If you are stacking ovens on a TurboChef oven
cart (24” = NGC-1217-1, 18” = NGC-1217-2),
make sure that the bottom oven is bolted to the cart
and the wheels are locked.
4. Attach the stacking bracket (P/N TC3-0323) to the
back of the bottom oven:
a. Remove the two screws that hold the top
panel to the back of the oven (see bottom
arrows on Figure 4).
b. Align the holes on the stacking bracket with
the holes on the oven and reinstall the screws.
5. Remove the legs of the oven that will be placed on
top. This requires two or more persons - at least
one person to lift and one to unscrew the legs.
6. Remove the screws from the oven that will be
placed on top (see top arrows on Figure 4).
7. Place this oven on top of the other (the one to which
the stacking bracket is attached).
WARNING: Do not attempt to lift the oven
with fewer than 2 people.
WARNING: Do not lift oven from front and back. FIGURE 4: Properly Stacked NGC Ovens
INSTALLATION, SPECIFICATIONS, AND MAINTENANCE
8. Align the holes on the bracket with the holes
on the top oven and reinstall the screws.
WARNING: Do not stack ovens over two-
high.
Programming
The oven is preprogrammed and ready to oper-
ate out of the box.
Initial Power-up
To turn on the oven, press the bottom-right soft
key next to the words OVEN ON on the display.
The oven will begin to warm up to its prede-
fined cooking temperature. This takes approxi-
mately 13 minutes.
When the warm-up cycle is completed, the oven
will beep and display the READY TO COOK.

INSTALLATION, SPECIFICATIONS, AND MAINTENANCE 5
DAILY MAINTENANCE FOR THE NGC
Before cleaning, check with the store for custom
cleaning instructions.
When cleaning the oven, use only TurboChef Oven
Cleaner. Any other cleaning products can damage
critical parts and may void warranty on those parts.
Supplies and Equipment
TurboChef Oven Cleaner (P/N 103180 USA,
103380 Intl), Oven Guard (P/N 103181 USA,
103381 Intl), nylon scrub pad, cleaning towel
Step 1: Prepare the Oven
Turn oven off by pressing the BACK key.
The oven will display OVEN OFF/COOLING DOWN.

xDO NOT attempt to clean oven during the cool
down cycle. Cooling takes appx. 90 minutes.
WARNING: The oven operates at appx. 500ºF
(260ºC) and may cause injury if not allowed
time to cool properly.
Step 2: Remove the Lower Access Panel
Wipe out any crumbs that have collected.
Step 3: Remove and Clean the Cooking Surface
If rack, wash, rinse, and sanitize.
If baking stone, gently dry-scrub with nylon pad.
If the stone gets wet, let it thoroughly air-dry.
Step 4: Lift Bottom Element
Be sure the bottom element is cool prior to lifting.
WARNING: The bottom element operates at
appx. 1000ºF (537ºC).
Step 5: Remove Particles and Spray Oven Interior
with TurboChef®Oven Cleaner
Using a damp towel, remove large food particles.
If stubborn stain is present, sparingly spray
TurboChef Oven Cleaner onto the stain.
Allow cleaner to penetrate for five (5) minutes.

xDO NOT saturate the bottom of the oven with
water or oven cleaner.
Step 6: Clean Oven Interior
Using a nylon scrub pad, clean the oven door
and cook cavity.
CAUTION: DO NOT apply pressure to the
wave guide covers. Breaking will result in a
non-warranty service call.
Step 7: Wipe Out Oven Interior
Wipe oven door, bottom element, and cook
cavity using a damp towel.
Step 8: Clean Lower Access Panel Area

xDO NOT spray any chemical in this area.
Step 9: Lower the Bottom Element and Reinstall the
Cooking Surface and Lower Access Panel
Step 10: Apply Oven Guard and Clean Oven Exterior
Spray Oven Guard on towel. Wipe sides of cook
cavity and inside of door.

xDO NOT spray Oven Guard directly into cook
cavity or wipe on nozzle plates/bottom element.
Wipe the oven exterior with a clean, damp towel.
Oven is ready to turn on.
10
9
876
1 2 3 4 5

Theory of Operation

THEORY OF OPERATION 7
THEORY OF OPERATION
The TurboChef NGC (Tornado) oven utilizes
three independent heat transfer mechanisms to
rapidly cook food.
The systems are as follows:
Convection
Infrared energy
Microwave 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 5 below represents the oven’s different sys-
tems and the critical components of each system.
Should a problem arise with any of the compo-
nents 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 CONVECTION SYSTEM
and/or BOTTOM IR AND CCV. Focus on MICROWAVE
SYSTEM if the oven is browning the food but not
heating the inside.
Part numbers are included on illustrations (where
applicable) and in the back of this manual. If an
item is not illustrated, the part number is provided
in the text.
Chapter 4
CONTROL SYSTEM
I/O Control Board
Keypad
Display
Mechanical Relays
Solid State Relay
Chapter 5
MICROWAVE SYSTEM
Magnetrons
High Voltage Transformers
Filament Transformers
High Voltage Capacitors
High Voltage Diodes
Fuses
Chapter 7
CONVECTION SYSTEM
Convection Heater
Blower Controller
Blower Motor
Hi-Limit Thermostat
Chapter 8
BOTTOM IR AND CCV
Bottom Infrared Element
Catalytic Converter
FIGURE 5: NGC (Tornado) Systems and Critical Components

THEORY OF OPERATION
8
GLOSSARY OF COMMON OPERATING TERMS
Off State
All the oven’s control systems are off and the cook cavity temperature is below 150ºF (66ºC).
Cool Down
A subset of the OFF STATE. During COOL DOWN, the oven will circulate the main convection blower until
the cook cavity temperature is below 150ºF (66ºC).
Ready State
The oven has successfully warmed to the predefined set temperature. At this point the oven control is
ready to receive cook commands via the keypad. The oven will maintain the set temperature in the
READY STATE.
Set Temperature, Cook Cavity (CCSP)
Predefined temperature of the cook cavity at which the oven cooks.
Set Temperature, IR Element (IRSP and IRSI)
IRSP is the set temperature of the IR element during a given cook cycle. Settings are determined on a
per-recipe basis. IRSI is the set temperature of the IR element during the READY STATE (or “idle”). IRSI
setting can be adjusted in the TEST MODE (page 16).
Actual Temperature, Cook Cavity (TCC)
The actual temperature registered by the cook cavity thermocouple.
Actual Temperature, IR Element (TIR)
The actual temperature registered by the IR element.
Edit Mode
Enables the user to change recipe and CCSP/IRSP temperature settings.
Warm-Up
The mode in which the oven warms itself to the set temperature.
Soak
The mode in which the oven temperature has reached the CCSP, and remains in warmup for an addi-
tional 8 minutes to allow cook cavity surfaces to warm. The oven will proceed to soak only if warm-up
was initiated when TCC < (CCSP - 126ºF) or TCC < (CCSP - 66ºC).
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, check oven statistics, and set the IRSI.

THEORY OF OPERATION 9
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.
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 can be set between 0 and 100% of the total cook time.
Total Cook Time
The total duration of a recipe.
Percentage (%) Time
An event subset that specifies the duration of the event. The sum of all event time percentages for a recipe
must equal 100%.
Percentage (%) Air
An event subset that specifies the relative amount of impingement airflow (speed of convection motor) dur-
ing an event. Valid between 10 and 100%.
NOTE: Maximum 100% = 7100 RPM blower motor speed. Blower motor speed scale is linear.
Percentage (%) Microwave (WAV)
An event subset specifying the microwave cycle during the event. Valid between 0 and 100%. For example,
if WAV is set to 30%, then microwave would be present in the cook cycle for 3 out of every 10 seconds.
Fault Code
A code assigned to an instance 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 oven will also log faults F1
through F6 in the Fault Log. See page 11 for more detail on faults and for viewing the fault log.

Fault Codes

11
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 12 for more detailed information.
When a fault is detected, the Fault Log will incre-
ment. However, if the fault is subsequently cleared
by some action, whether service related or not, the
Fault Log will not decrement.
TO VIEW FAULT CODES
To view the Fault Log, simultaneously press the “4”
and “6” keys while the oven is in the OFF STATE.
The oven will display all faults logged. Figure 6.
Each fault will log up 255 instances before rolling
back to zero. To zero the log, see pages 14-15
(TEST MODE).
NOTE: The Fault Log also displays cook counts,
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 has only one event, the oven must complete
the entire cook cycle in order to count it.
FAULT CODE DEFINITIONS
F1: Blower Running Status Bad
Fault is displayed when the motor controller
indicates no running status.
The motor and motor controller are monitored con-
tinuously in all modes with special handling in SELF
TEST and TEST MODE. If a fault is detected, the con-
trol will terminate a cook cycle and display F1:
BLOWER. Upon turning on the oven, the control will
attempt to restart the motor. If the restart is suc-
cessful, the fault code will be cleared. The fault is
also cleared from the display at the onset of cooking
or when the blower motor is tested in TEST MODE.
F2: Cook Temperature Low
Fault is displayed if the cook cavity temperature is
more than 84ºF (47ºC) below the set temperature
after five (5) seconds into a cook cycle.
The fault is cleared from the display at the onset of
cooking if the cook cavity temperature is within
84ºF (47ºC) 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 from the display at the onset of
a cook cycle if the CT detects current or when the
magnetron is successfully energized in TEST MODE.
F4: Door Monitor Defective
Fault is displayed when the control detects that the
monitor interlock switch unlatches before the pri-
mary or secondary interlock switches.
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 from the display
when the oven is powered off and then back on.
COOKCOUNT
F1BLOWER
F2LOWTEMP
F3MAGCURR
F4MONITOR
F5MAGTEMP
F6TEMP
S/NXXXXXX
NGCVXXXX XXXXXX
0
0
0
0
0
0
0
FIGURE 6: Fault Log
FAULT CODES