Blodgett C70 Service Manual
C70
CONVECTION MICROWAVE OVEN
SERVICE AND REPAIR MANUAL
BLODGETT OVEN COMPANY
www.blodgettcorp.com
50 Lakeside Avenue, Box 586, Burlington, Vermont 05402 USA Telephone (800) 331-5842, (802) 860-3700 Fax: (802)864-0183
PN T0582 Rev F (3/01)
E 2000 --- G.S.Blodgett Corporation
TABLE OF CONTENTS
READ THIS FIRST i.........................................................
Important Safety Instructions ii...............................................
Precautions to Avoid Possible
Exposure to Excessive Microwave Energy iii....................................
Precautions to be Observed Before and During
Servicing to Avoid Possible Exposure to Excessive Microwave Energy iv...........
Grounding Instructions v.....................................................
RF Interference Considerations vi.............................................
Section 1 Installation Specs
Oven Description 1--- 1....................................................
Installation 1---1.........................................................
Section 2 Cleaning & Operating
Basic Cleaning Procedures 2---1...........................................
Oven Cavity Filter Cleaning 2---2...........................................
Glossary of Common Operating Terms & Error Messages 2---3................
Operational Flow Chart 2---4..............................................
Programming Flow Chart 2---6.............................................
Section 3 Test
Test Function Quick Reference 3---1........................................
Test Function Detailed Description 3---2.....................................
Section 4 Electrical Compartment
Key Sequence of Operation --- Failure Mode Analysis 4---1....................
Electrical Component Locations 4---2.......................................
Electrical Component Description with Voltage Information 4---3...............
Door Switches and Circuit Breakers 4---5...................................
Door Switch Adjustment 4---6.............................................
Door Removal and Replacement 4---9......................................
C70 Schematic 4---12.....................................................
Section 5 Convection Circuit
Catalytic Converter 5---1..................................................
Convection Element and Thermocouples 5---2...............................
Thermoelectric Voltage in Millivolts --- T ype K Thermocouple 5---3...........
Convection (Blower) Motor Operation 5---4..................................
Blower Motor Controller Fault Codes & T roubleshooting 5---5..................
TABLE OF CONTENTS
Section 6 Microwave Circuit
Measuring for Microwave Radiation Leakage 6---1...........................
Magnetron Circuit 6---2...................................................
Magnetron Testing 6---3..................................................
Magnetron Removal and Replacement 6---3.................................
Component Testing 6---4..................................................
Transformer Specifications 6---5...........................................
Control Circuit Board 6---6................................................
READ THIS FIRST
TECHNICAL SUPPORT PHONE NUMBER
1-888-992-6624
This Service and Repair manual is setup for use by qualified technicians only.If you are unfamiliarwiththiso ven, callthefactoryat thetollfree numberabovefor technicalassistance.Technical
support can be reached 24 hours a day, seven days a week.
Before working on the Acellis C-70 oven you must first read the safety instructions on the following
pages. The Accellis C-70 is a combinationconvection/microwave oven. While servicing this oven, an
RFmetermustbeusedatalltimestocheckformicrowaveleakage.ThisRFreadingmustberecorded
on your work invoice.
Very often poor cleaning will result in microwave leakage. Please refer to the first two sections of this
manual (INTRODUCTION and CLEANING & OPERATION) for information on the proper cleaning procedures.
Before removing the metal skin to access the electrical components in this oven, the power must be
shut off and the oven unplugged. Wait at least one full minute before removing the oven skin so that
themagnetron circuitcan self-discharge.FAILURETODOSOMAYRESULTINDEATHORSERIOUS
INJURY.
This oven has a one time registration feature on initial start-up. The Accellis C-70 will not operate until
youhave called and registered the ovenlocationand phone number with technicalsupport. Upon registration, an access code will be issued. B e sure that you have the location of the installation site and
phonenumberbeforecallingforregistration.
This manual is divided into seven (7) chapters as follows:
1. INSTALLATION SPECS --- This chapter includes oven specifications and the parameters for
proper installation.
2. CLEANING & OPERATION --- Improper cleaning can and will affect the operation of this oven. This
chapter includes a brief description of the cleaning and operation procedures of the oven and the procedure to edit or change a cooking
program.
3. TEST --- This chapter details the Test Mode, which allows the technician to
operateindividualcomponentsor sectionof theA ccellis C-70oven.
Using this feature will isolate most electrical troubleshooting
problems.
4. ELECTRICAL COMPARTMENT --- Thischapter identifiesthe electricalcompartment componentsa nd
provides voltage information.Usethekey to helpisolateelectrical
troubleshooting problems.
5. CONVECTION &
CATALYTIC CONVERTER --- This chapter provided information on the convection and blower
motorspeed control.Removaland cleaningofthe catalyticconverter are also provided.
6. MICROWAVE CIRCUIT --- This chapter includes informationon the microwave circuitand stirrer motor.
i
IMPORTANT SAFETY INSTRUCTIONS
WHEN USING ELECTRICAL APPLIANCES, THE FOLLOWING
BASIC SAFETY PRECAUTIONS SHOULD BE STRICTLY ADHERED TO:
WARNING!!
To reduce the risk of burns, electric shock, fire, injury to persons or exposure toexcessive
microwave energy:
7. Read all instructions before using the appliance.
8. Readandfollow the specificPRECAUTIONS TOAVOID POSSIBLE EXPOSURE TOEXCESSIVE
MICROWAVE ENERGY found on page iii.
9. This appliance must be grounded. Connect onlyto properlygrounded outlet. SeeGROUNDING
INSTRUCTIONS found on page iv.
10. Install or locate this appliance only in accordance with the provided installation instructions.
11. Someproducts such as whole eggs andsealed containers --- forexample, closed glass jars --- may
explode and SHOULD NOT be heated in this oven.
12. Use this appliance only for its intended use as described in the manual. DO NOT 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.
13. Children SHOULD NOT use this appliance.
14. DO NOT operate this appliance if it has a damaged cord or plug, if it is not working properly, or if
it has been damaged or dropped. See POWER SUPPLY CORD REPLACEMENT found on page
iv .
15. This appliance should be servicedonly by qualified service personnel. Contact the nearestautho-
rized service facility for examination, repair or adjustment.
16. DO NOT cover or block any openings on the appliance.
17. DO NOT store this appliance outdoors. DO NOTuse this product near water --- for example, near
a kitchen sink, in a wet basement, or near a swimming pool.
18. DO NOT immersecordorpluginwater.
19. Keep cord away; from heated surfaces.
20. DO NOT letcordhangoveredgeoftableorcounter.
21. DO NOT useawaterjetforcleaning.
22. See the Maintenance section of this manual.
23. To reduce the risk of fire in the oven cavity:
a.) DONOTovercookfood.Carefully attendappliance ifpaper,plastic, orother combustiblemate-
rials are placed inside the oven to facilitate cooking.
b.) Removewiretwist---tiesfrompaperorplasticbaginoven.
c.) Ifmaterials insidethe ovenshould ignite,keep oven doorclosed,turn oven off,and disconnect
thepowercord,orshutoffpoweratthefuseorcircuitbreakerpanel.
d.) DONOTuse the cavityforstorage purposes.DONOTleavepaper products, cooking utensils,
or food in the cavity when not in use.
SAVE THESE INSTRUCTIONS
ii
PRECAUTIONS TO AVOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROWAVE ENERGY
1. DO NOT attempt to operate this oven with the door open since open---door operation can result
inharmfulexposuretomicrowaveenergy.Itisimportantnottodefeatortamperwiththe safetyinterlocks.
2. DO NOT place any object between the ovenfront faceand the door orallow soilor cleaner residue
to accumulate on the sealing surfaces.
3. DONOToperate the oven if itis damaged. Itis particularly important that the ovendoorcloseproperly and that there is no damage to the:
a.) Door (bent).
b.) Hinges and latches (broken or loosened).
c.) Door seals and sealing surfaces.
4. The oven SHOULD NOT be adjusted orrepaired byanyoneexcept properlyqualified servicepersonnel.
SAVE THESE INSTRUCTIONS
iii
PRECAUTIONS TO BE OBSERVED BEFORE
AND DURING
SERVICING TO AVOID POSSIBLE EXPOSURE
TO EXCESSIVE MICROWAVE ENERGY
1. DO NOT operate or allow the oven to be operated with the door open.
2. Make the following safety checks on all ovens to be serviced before activating the magnetron or
other microwave source, and make repairs as necessary:
a.) Interlock operation.
b.) Proper door closing.
c.) Seal a nd sealing surfaces (arcing, wear, and other damage).
d.) Damage to or loosening of hinges and latches.
e.) Evidence of dropping or abuse.
3. Beforeturningonmicrowavepower foranyservicetest orinspection withinthemicrowavegenerating compartments, check the magnetron, wa ve guide, or transmission line, and cavity for proper
alignment, integrity , and connection.
4. If the oven is operativeprior to servicing, a microwave emission check should be performed prior
to servicing the oven. Refer to page NO TAG of this manual for microwaveleakage testing procedure.
5. Anydefectiveor mis-aligned componentsin theinterlock, 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.
6. A microwave leakage check to verify compliance with the Federal Performance Standard MUST
BE performed on each oven prior to release to the owner. Refer to page NO TAG of this manual
for microwave leakage testing procedure.
SAVE THESE INSTRUCTIONS
iv
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 having a grounding wire w ith a grounding plug. The plug must be plugged into an outlet
that is properly installed and grounded.
WARNING!!
Improper use of the grounding can result in a risk of electric shock.
Consult a qualified electrician or serviceman if the grounding instructions are not completely understood, or if doubt exists as to whether the appliance is properly grounded.
DO NOT 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 or its service agent
or a similarly qualified person in order to avoid a hazard.
SAVE THESE INSTRUCTIONS
v
RF INTERFERENCE CONSIDERATIONS
This oven generates radio frequency signals. This device h as been tested and determined to be in
compliance with applicable part of FCC part 18 requirements and to the protection requirements of
CouncilDirective89/336/EECon theapproximationofthelaws ofthe Member Statesrelating toelectromagneticcompatibility at thetime of manufacture. However, someother equipment may exhibitsensitivity to signals below these limits resulting in interference with that equipment.
If your equipment experiences interference, the following steps should be considered:
1. Increase the physical separation between this oven and the sensitive equipment.
2. If the sensitive device can be grounded, do so following accepted grounding practices.
3. If battery powered microphones are being affected, insure that the batteries are fully charged.
4. Keep sensitive equipment on electrically separate circuits, if possible.
5. DO NOT route intercom wires, microphone wires, or speaker cables near oven.
SAVE THESE INSTRUCTIONS
vi
CHAPTER 1
INSTALLATION SPECS
ACCELLIS C70
OVEN DESCRIPTION
SPECIFICATIONS C70
Dimensions (single unit) 29” W x 21.5” H x 32.25” D (74.9 cm x 54.6 cm x 81.9 cm)
Maximum Input 8.0 KW/Hr.
Power Supply 208 VAC, 50/60 Hz, 1Ô, 39 amp,3 wire including ground
240 VAC, 50/60 Hz, 1Ô, 36 amp,3 wire including ground
Microwave Frequency 2.45 GHz
Connections including ground The unitissupplied with a 6’ power cord with an approvedplug.
The outlet box, receptacle and wall plate are to be furnishedby
the installing contractor.
Maximum Power Usage
Convection Oven
Microwave Oven
5Kw
2Kw
INSTALLATION
The Blodgett Accellis oven is manufactured to
comply with applicable CE, UL, CUL, FDA, and
FCCrequirements.Inaddition,the unitisULclassified to NSF 4. All equipment isdesigned and certified for safe operation when installed in accordancewithlocal and ornationalcodes.Many local
codes exist, and it is the responsibility of theowner
and installer to comply with these codes.
In no event shall the manufacturer assume any liabilityfor damages orinjuryresulting frominstallations which are not in compliance with the instructionsandcodeslistedabove.
WARNING!!
DEATH, INJURY, AND EQUIPMENT DAM-
AGEcould resultfrom improperinstallation
of this oven or installation of a unit whic h
has been damaged during shipment or
storage. Either of these conditi on s could
void the equipment warranty.
DO NOT INSTALL an oven suspected of
damage.
INSTALL this oven according to the policies and procedures outlined in this
manual.
TABLE 1
OVEN LOCATION
The well planned and proper placement of your
oven will result in long term operator convenience
and satisfactory performance.
Besuretoplacetheoveninan areawhichisaccessible for proper operation and servicing.
The countertop or work surface must be able to
support the weight of 200 pounds. The manufacturer shallnot assume liabilityfor damage or injury
resulting from improper installation of equipment
including temporary or unstable work stations or
countertops.
There must be 2” (5.08 cm) between thetop ofthe
unit a nd any shelf or other surface.
The oven must be installedlevel front to back and
side to side. The oven legs may be bolted to the
counter top if desired.
1 --- 1
CHAPTER 2
CLEANING & OPERATING
ACCELLIS C70
BASIC CLEANING PROCEDURES
PROBLEMS ASSOCIATED WITH IMPROPER
CLEANING
The Accellis C70 oven may not be operating correctly because it is not being cleaned properly. If
thedoorisleakingmicrowaves,erraticoperationof
the display and other electrical components can
occur. Also food deposits left in the oven will turn
into black carbon from the high heat. Carbon can
cause arking inside the cooking area and can reflect energy back to the magnetron.
Ifa customer tellsyou theyare experiencingcooking performance problems, carefully inspect the
cookingplatter and waveguidecap for chips. Ifthe
platter or waveguide cap are chipped and soaked
in w a ter, they will absorb the water. The water will
then be heated instead of the food product. The
chipped part must be replaced.
DAILY CLEANING
1. Carefully remove the ceramic cooking platter
and wave-guide cap. Spray both pieces generously with non-lye non-caustic oven cleaner
or non-lye non-caustic degreaser and set
aside to allow the cleaner to penetrate. DO
NOT soak the Ceramic Cook Platter or Waveguide Cap in water.
2. Clean the ceramic cooking platter, and wave
guide cap using brushes and scrub pads.
Rinsetoremoveallcleaneranddebris. Inspect
for damage and replace as required.
3. Reinstall the clean wave-guide cap into the
oven. This will protect the wave-guide seal
whilethecookchamberiscleaned.
4. To clean the interior of the oven, use a 3”x5”
green scrub pad. Use a non lye based cleaner
on tough spots. DONOT wash out t he interior
cooking area. The w aveguide quartz seal is
not a water tight seal. Wipe out the oven with
a damp rag. If the door area needs cleaning,
becareful nottodamagethe smallrubbergasket around the door shunt area.
5. Remove the lower access panel and grease
collection pan. Empty, clean and reinstall the
pan.
6. Verify the louvers on the front and side of the
oven are clean of lint and unobstructed.
MONTHLY CLEANING
1. Remove and clean the exhaust cover from the
back of the oven.
Cook Platter
Exhaust
Cover
Waveguide
Cap
FIGURE 1
2 --- 1
Grease
Tray
Lower Access
Panel
OVEN CAVITY FILTER CLEANING
CLEANING & OPERATING
Filter should be cleaned once a week, depending
on food product and unit run time.
1. Turn the C70 off and disconnect power to the
unit.
2. Allowthe unit to coolbefore cleaningthe filter.
3. Open the oven door.
4. Carefully remove the ceramic platter.
5. The oven cavity filter is located in the bottom
left corner .
6. Remove the two screws.
7. Pull the two tabs on the filter to remove it.
8. Clean the filter with soap and warm water.
Filter
Tab
9. Clean the oven filter cavity.
DO NOT reach into the air return more than
six inches.
10. Reinstall the filter and secure with the two
screws.
DO NOT over tighten the screws.
WARNING!!
DO NOT operate the unit without the
oven filter installed. Failure to do so
may result in prematurefailure of the
heater element.
Tabs
Screws
Screws
Tab
Filter
FIGURE 2
2 --- 2
ACCELLIS C70
GLOSSARY OF COMMON OPERATING TERMS & ERROR MESSAGES
OVEN OPERATING COMPONENTS
Display --- Prima ry interfa ce t o relay messa ges to
the operator.
Keypad --- Primary interface for the operator to
control the oven.
Cook Chamber --- Cavity in which the food prod-
ucts are cooked.
PRODUCT RECIPES
Recipe --- The food product recipe programming
consistsoftime, percentage ofhotairflow(AIR)required and microwave (MW) level required.
Cook Cycle --- Time of operation for a recipe.
Cook Event – Segment of a recipe, up to 6 events
can be used for each recipe.
Duration --- Time, in seconds, of a single cook
event.
Air --- Percent of convection air flow during a cook
event.
MW --- Percent of microwave used during a cook
event.
Cook Temperature Set Point --- Tempera ture
should be a constant parameter. The same cook
temperature should be used by all cook recipes.
MODES
Mode – The software environment which allows
certain operations t o occur. There a re several
modes, STANDBY, COOK, WARM UP and COOL
DOWN in which the oven can operate.
Standby Mode --- The standby mode is similar to
oven off. In standby there is no power to the oven.
There is power to the control, however, the oven
will not operate in standby mode.
Warm-Up Mode --- Mode to bring the oven up to
the cook temperature set point.
Cool-Down Mode -- - Turns off all oven components
except the cooling fan and circulation blower.
ERROR MESSAGES
LO MAG CURR – the magnetron transformer is
drawing less than 7 amps. The normal current
draw is approximately9 amps. The current draw is
beingmonitored bythecontrol boardwhich has an
inductance ring on it.
LOCOOK TEMP – thetemperature s et for the C70
is not being maintained. It is referenced by two J
type thermocouples.
MAG OT – the snap disk on the magnetron has
overheated and has tripped.
BLOWERSTAT –the controlboardisnotreceiving
the proper output from the convection (blower)
motor speed control.
LO MAG FLUX – there is a small antenna in the
launchtube ofthe waveguide. Thisantenna orRF
cable is attached to the control circuit board. The
control circuit board amplifies the signal and looks
foracertainfluctuationwhichindicates themagnetronis operating and the stirrer blade inthe launch
tube is rotating. When not cooking a minimum
change of 20 is being looked for. When you are
cooking a product a minimumchange of 10 is being looked for. When viewing the RF display, it will
fluctuatequicklywithamaximumvalueof120(plus
or minus 20).
ELECTOVR TMP – the j type thermocouple connected to the control board is above 140_F.
OVEN DOOR OPEN – (during cook cycle) the
cooking door has been opened during a cook
cycle and has not been closed properly.
Cook Mode --- Mode used to perform the normal
oven operations, such as, monitor the key pad for
requests to cook or change mode, and maintain
the oven at the cook temperature set point.
2 --- 3
OPERATIONAL FLOW CHART
START
(Blank Display if off
for over one hour)
If the oven has
been used in
the last hour,
proceed to
here.
Press any key
to initialize
CLEANING & OPERATING
Press soft key to
select menu.
Display reads
OVEN OFF
Press soft key
next to OVEN ON
(to right of display)
Display reads
SET TEMP XXX
PRESS ENTER
Use theARROW keys to change
the temperatue. The range is
_
between 350
_
increments).
in 25
Press ENTER to
accept value.
Display reads
COOLING DOWN
F and 520_F
The oven will
default to the
programmed temperature
if no change
If oven
temp
high
is entered.
If oven
temp
low
Display reads
WARMING UP
Press soft key
to pick submenu.
Display reads
XX:XX
COOKING
MENU
SUBMENU
Cooking begins
Open Door
When finished
display reads
DONE
Please remove
food from oven
Cook More
A
See
next
page
Display reads
READY TO COOK
(oven beeps)
(oven to set temp)
2 --- 4
Press
STOP key
B
See
next
page
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