Vulcan-Hart VC4ED User manual

A product of VULCAN-HART LOUISVILLE, KY 40201-0696
F25105 (December 2001)
- NOTICE -
This Manual is prepared for the use of trained Vulcan Service
Technicians and should not be used by those not properly
qualified. If you have attended a Vulcan Service School for this
product, you may be qualified to perform all the procedures
described in this manual.
This manual is not intended to be all encompassing. If you have
not attended aVulcan ServiceSchool forthisproduct, you should
read, in its entirety, the repair procedure you wish to perform to
determine if you have the necessary tools, instruments and skills
required to perform the procedure. Procedures for which you do
not have the necessary tools, instruments and skills should be
performed by a trained Vulcan Service Technician.
Reproduction or other use of this Manual, without the express
written consent of Vulcan, is prohibited.
VC4ED SHOWN
SERVICE MANUAL
VC4E & VC6E
SERIES
FULL SIZE
ELECTRIC CONVECTION
OVENS
MODEL ML
VC4ES 126743
VC4ED 126744
VC4EC 126745
VC6ES 126746
VC6ED 126747
VC6EC 126748

FULL SIZE ELECTRIC CONVECTION OVENS
F25105 (December 2001) Page 2 of 60
TABLE OF CONTENTS
GENERAL............................................................................. 4
Introduction ........................................................................ 4
Installation ......................................................................... 4
Operation.......................................................................... 4
Cleaning .......................................................................... 4
Lubrication ......................................................................... 4
Tools ............................................................................. 4
Specifications ...................................................................... 5
REMOVALANDREPLACEMENTOFPARTS ................................................. 6
Covers And Panels .................................................................. 6
Control Panel Components ............................................................ 7
Component Panel Components ......................................................... 8
Temperature Probe (Solid State Control) .................................................. 8
HeatingElements ................................................................... 9
BlowerAndMotor .................................................................. 10
DoorSwitch ....................................................................... 11
Door Window ...................................................................... 12
Oven Doors and Bearings (Independent Doors) ............................................ 12
Oven Doors (Simultaneous Doors) ...................................................... 13
Door Catch Roller Assembly (Independent Doors) .......................................... 14
Mechanical (KX) Thermostat .......................................................... 14
HighLimitThermostat ............................................................... 15
InteriorLights...................................................................... 15
CoolingFan....................................................................... 16
SERVICEPROCEDURESANDADJUSTMENTS .............................................. 17
SolidStateTemperatureControlCalibration .............................................. 17
Mechanical (KX) Thermostat Calibration ................................................. 18
SolidStateTemperatureControlTest ................................................... 19
Temperature Probe Test (Solid State Control) ............................................. 20
HeatingElementTest ............................................................... 20
BlowerAdjustment.................................................................. 21
DoorAdjustment ................................................................... 22
Door Catch Roller Adjustment (Independent Doors) ......................................... 22
DoorSwitchAdjustment.............................................................. 23
Door Chain Adjustment (Simultaneous Doors) ............................................. 23
ComputerControl .................................................................. 24
ComputerControlTemperatureCalibration ............................................... 26
Computer Control Operational Test ..................................................... 26
ELECTRICALOPERATION .............................................................. 29
Component Function ................................................................ 29
Component Location ................................................................ 30
Sequence of Operation .............................................................. 34
VC4ES, VC6ES with Mechanical KX Thermostat ....................................... 34
VC4ED,VC6EDwithSolidStateTemperatureControl................................... 34
TimerCycle,Cooking(KXThermostatorSolidStateControl) ............................. 35
CoolDownCycle(KXThermostatorSolidStateControl)................................. 35
VC4EC,VC6EC(ComputerControl) ................................................ 35
Temperature and Time Cycle (Cooking) .......................................... 36
Cook and Hold Cycle ........................................................ 36
CoolDownCycle ........................................................... 36
Schematics ....................................................................... 37
VC4ES, VC6ES with Mechanical (KX) Controls, 208-240V ................................ 37
VC4ES, VC6ES with Mechanical (KX) Controls, 480V ................................... 38
VC4ED, VC6ED with Solid State Temperature Control, 208-240V .......................... 39
VC4ED, VC6ED with Solid State Temperature Control, 480V .............................. 40

FULL SIZE ELECTRIC CONVECTION OVENS
F25105 (December 2001)Page 3 of 60
VC4EC, VC6EC Computer Control, 208-240V (Roast & Hold Standard) ...................... 41
VC4EC, VC6EC Computer Control, 480V (Roast & Hold Standard) ......................... 42
WiringDiagrams ................................................................... 44
VC4ES, VC6ES with Mechanical (KX) Control, 208-240V ................................. 44
VC4ES, VC6ES with Mechanical (KX) Control, 480V .................................... 46
VC4ED, VC6ED with Solid State Temperature Control, 208-240V .......................... 48
VC4ED, VC6ED with Solid State Temperature Control, 480V .............................. 50
VC4EC, VC6EC Computer Control, 208-240V (Roast & Hold Standard) ...................... 52
VC4EC, VC6EC Computer Control, 480V (Roast & Hold Standard) ......................... 54
TROUBLESHOOTING .................................................................. 56
All Models ........................................................................ 56
Computer Control Models Only ........................................................ 57
CONDENSED SPARE PARTS LIST ........................................................ 60
© Vulcan 2001

FULL SIZE ELECTRIC CONVECTION OVEN - GENERAL
F25105 (December 2001) Page 4 of 60
GENERAL
INTRODUCTION
Procedures in this manual will apply to all models unless specified. Pictures and illustrations can be of any model
unless the picture or illustration needs to be model specific.
Models
MODEL FEATURES OPTIONS
CAVITY
DEPTH TEMPERATURE CONTROL DOORS (50/50) COOK TIMER COOK TIMER COOK & HOLD
VC4ES 426.5" Mechanical (KX) Independent 1, 2 1-Hour Dial 5-Hour Dial N/A
VC4ED 26.5" Solid State Independent 1, 3 1-Hour Dial 5-Hour Dial N/A
VC4EC 26.5" Computer Independent 1, 3 24-Hour Digital Built in Built in
VC6ES 430.5" Mechanical (KX) Independent 1, 2 1-Hour Dial 5-Hour Dial N/A
VC6ED 30.5" Solid State Independent 1, 3 1-Hour Dial 5-Hour Dial N/A
VC6EC 30.5" Computer Independent 1, 3 24-Hour Digital Built in Built in
NOTES:1. Simultaneous doors are optional (with or w/o window).
2. Stainless steel doors w/o window (standard).
3. Stainless steel doors with window (standard)
4. In February 2001, this model was discontinued.
INSTALLATION
Refer to the Instructions Manual for detailed
installation instructions on single or stacked ovens.
OPERATION
Refer to the Instructions Manual for specific
operating instructions.
CLEANING
Refer to the Instructions Manual for specific
cleaning instructions.
LUBRICATION

Cavity blower motor has sealed bearings and
requires no additional lubrication.

Huskey’s TF1000 grease or equivalent high
temperature Teflon grease.
TOOLS
Standard

Standard set of hand tools

VOM with A.C. current tester (Any quality VOM
with a sensitivity of at least 20,000 ohms per volt
can be used)

Gear Puller to remove blower

Temperature tester (thermocouple type)
Special

Manometer

Clamp on amp meter

Spring force gauge, pull type with a minimum 30
pound full scale range (purchase locally)

RTV sealant, 736 DOW silicone high temp
(P/N 542133) or equivalent

FULL SIZE ELECTRIC CONVECTION OVEN - GENERAL
F25105 (December 2001)Page 5 of 60
SPECIFICATIONS
Electrical
MODEL TOTAL POWER
(KW)
AMPERAGE - 3 PHASE/ 60HZ
PER LINE 1RECOMMENDED
CIRCUIT
PROTECTION 2
208V 240V 480V 208V 240V 480V
VC4ES
VC4ED
VC4EC
VC6ES
VC6ED
VC6EC
12.5 353315454020
NOTES: 1. Amperage values in the table are nominal.
Tolerance is +5/-10%.
2. Complied in accordance with National Electric Code,
ANSI/NFPA 70, latest edition.
MODEL TOTAL POWER
(KW)
AMPERAGE - 1 PHASE/ 60HZ
PER LINE 1RECOMMENDED
CIRCUIT
PROTECTION 2
208V 240V 480V 208V 240V 480V
VC4ES
VC4ED
VC4EC
VC6ES
VC6ED
VC6EC
12.5 605226807035
NOTES: 1. Amperage values in the table are nominal.
Tolerance is +5/-10%.
2. Complied in accordance with National Electric Code,
ANSI/NFPA 70, latest edition.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001) Page 6 of 60
REMOVAL AND REPLACEMENT OF PARTS
COVERS AND PANELS
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
Top Front Cover
1. The top front cover is secured with four (4)
screws, two on each side of cover. Remove
these screws then remove the cover from the
oven.
2. Reverse the procedure to install.
Bottom Front Cover
1. The bottom front cover is secured with four (4)
screws, two on each side of cover. Remove
these screws then remove the cover from the
oven.
2. Reverse the procedure to install.
Control Panel
1. Remove three (3) screws on the right side
which secure the control panel then pull the
panel away from the oven.
NOTE: If the oven has a mechanical (KX type)
thermostat, it must be removed from the control
panel first, before removing the control panel.
2. Disconnect the temperature probe leads from
the solid state temperature control.
3. Unplug the wire harness connector to the
control panel components.
4. Reverse the procedure to install.
Right Side Panel
1. Remove the two screws near front of oven,
which secure the bottom front cover and control
panel.
2. Remove the remaining seven screws securing
the right side panel.
3. Pull the right side panel out at the bottom then
down to remove.
4. Reverse the procedure to install.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001)Page 7 of 60
Left Side Panel
1. Remove the screws which secure the left side
of the top front cover, bottom front cover and
control panel.
2. Remove the seven screws securing the left
side panel.
3. Pull the left side panel out at the bottom then
down to remove.
4. Reverse the procedure to install.
CONTROL PANEL
COMPONENTS
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
Removable Components
1. Remove the control panel as outlined under
"COVERS AND PANELS".
2. Remove the component being replaced.
3. Reverse the procedure to install the
replacement component, then check oven for
proper operation.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001) Page 8 of 60
COMPONENT PANEL
COMPONENTS
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
Removable Components
1. Remove the right side panel as outlined under
"COVERS AND PANELS".
NOTE: If right side panel is not accessible, this
component can be serviced by removing the control
panel as outlined under "COVERS AND PANELS".
2. Disconnect the wire leads to the component
being replaced.
3. Remove the component.
4. Reverse the procedure to install the
replacement component and check oven for
proper operation.
TEMPERATURE PROBE
(SOLID STATE CONTROL)
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Remove the right side panel as outlined under
"COVERS AND PANELS".
NOTE: If right side panel is not accessible, this
component can be serviced by removing the control
panel as outlined under "COVERS AND PANELS".
2. Disconnect the probe leads from the solid state
temperature control.
3. Remove the racks and right rack support.
4. Remove the probe guard or mounting clips.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001)Page 9 of 60
5. Remove probe by pushing it through the oven
wall and into the control panel area.
NOTE: The hole in the oven cavity wall does not
line up straight with the oven cavity outer shell,
therefore the probe must be removed at an angle.
6. Reverse the procedure to install the
replacement probe.
7. Adjust the temperature control as outlined
under "SOLID STATE TEMPERATURE
CONTROL CALIBRATION" in "SERVICE
PROCEDURES AND ADJUSTMENTS".
HEATING ELEMENTS
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
NOTE: Starting with production in October, 2001,
the top cavity panel will have 3/4" square holes for
easier element removal. Ovens manufactured prior
to this date have 1/2" round holes that sometimes
make it difficult to remove elements thru the cavity.
A serial number cut off will not be available. Follow
the procedures for element removal as outlined
below.
Front Access
1. Remove the oven racks and rack supports.
2. Remove the "top" door seal from the oven.
3. Determine if the heating element to replace is
on the left or right side in the oven cavity. The
element locations from front to back are: Right
side - R1, R2 & R3; Left side - R4, R5 & R6.
A. Measure the current draw of the heating
elements as outlined under "HEATING
ELEMENT TEST" in "SERVICE
PROCEDURES AND ADJUSTMENTS".
4. From inside the oven cavity, remove the
perforated panel from the same side of the
element being replaced.
A. If removing the right side panel, also
remove the probe guard or mounting clips.
B. Run the probe wire thru the panel opening
before lifting panel out.
5. From the element being replaced, remove the
hold down clamps, the mounting bracket
screws at the top, then remove the element.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001) Page 10 of 60
LEFT SIDE ELEMENTS SHOWN
NOTE: The mounting bracket is sealed with RTV
which may still hold the element after the screws are
removed. Also, in some cases, the ring terminal
connected to the element may interfere with easy
removal. If access to the left side panel and/or the
top panel is available, see "ALTERNATE ACCESS".
6. Disconnect the lead wires from the element.
7. Clean RTV residue from the mating surface
inside the oven, apply new high temperature
RTV to the heating element mounting bracket
and reverse procedure to install.
8. Check for proper operation.
Alternate Access
If the heating element is not removing easily from
inside the oven cavity, and access to the left side
panel and/or the top panel is available, this alternate
removal method may be used.
NOTE: On stacked ovens, if the bottom oven is
being serviced and the heating element to replace is
on the right side, the ovens must be unstacked to
access the heating element terminals through the
top. Once unstacked, follow the removal procedure
below.
1. Perform steps 1 thru 4 under "FRONT
ACCESS".
2. If the element is on the left side:
A. Remove the left side panel and pull back
the insulation at the top to expose the
element terminals.
B. Remove the lead wires from the element
being replaced. Proceed to step 4.
3. If the element is on the right side:
A. Remove the top panel and pull back the
insulation to expose the element
terminals.
B. Remove the lead wires from the element
being replaced.
4. From the same element, remove the two
clamps holding the element vertical, the
screw’s securing mounting bracket at the top,
and then remove the element.
NOTE: The mounting bracket is sealed with RTV
which may still hold the element after the screws are
removed.
5. Clean RTV residue from the mating surface
inside the oven, apply new high temperature
RTV to the heating element mounting bracket
and reverse procedure to install.
6. Check for proper operation.
BLOWER AND MOTOR
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Take out the racks and rack supports.
2. Remove screws securing baffle panel and
remove the panel.
3. If replacing:
A. Blower Only - Loosen set screws on
blower hub and using a bearing puller,
remove blower from motor shaft.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001)Page 11 of 60
1) Reverse procedure to install and
adjust blower position as outlined
under "BLOWER ADJUSTMENT" in
"SERVICE PROCEDURES AND
ADJUSTMENTS".
B. Motor - perform step 3A and continue
procedure.
4. Remove the nuts that secure the motor
mounting plate to the rear wall.
5. Place a piece of cardboard on the bottom of
the oven cavity to protect its surface from any
damage during motor assembly removal.
6. Pull the motor assembly into the oven cavity
and place it on the cardboard.
7. Remove the junction box cover from the motor,
disconnect lead wires and remove the conduit.
8. Remove motor mounting bolts and flat washers
then lift the motor from the mounting plate.
9. Position the replacement motor on the motor
mounting plate and install mounting bolts and
washers. Hand tighten mounting bolts only.
10. Reconnect lead wires at the motor, replace
conduit and junction box cover.
NOTE: Check data plate on motor for wiring
schematic. The motor must rotate clockwise when
viewed from the shaft end.
11. Slide blower onto motor shaft until hub is flush
with end of shaft then tighten set screws.
12. Adjust motor position until blower is parallel to
motor mounting plate as outlined under
"BLOWER ADJUSTMENT" in "SERVICE
PROCEDURES AND ADJUSTMENTS".
13. Position motor mounting plate on the rear wall
and secure with nuts and washers.
14. Replace the baffle panel.
15. Remove cardboard from the bottom of the
oven cavity.
16. Check oven for proper operation then replace
rack guides and racks.
DOOR SWITCH
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Remove the top front cover as outlined under
"COVERS AND PANELS".
2. Disconnect the lead wires to the door switch.
3. Remove the switch.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001) Page 12 of 60
4. Reverse procedure to install the replacement
switch and check for proper adjustment as
outlined under "DOOR SWITCH
ADJUSTMENT" in "SERVICE PROCEDURES
AND ADJUSTMENTS".
DOOR WINDOW
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Remove the screws at the top and bottom of
door.
2. Independent doors:
A. Remove the door handle then remove the
outer door panel.
B. Lift out the inner door panel and window
assembly.
NOTE: Left door only - remove door seal from
the inside edge of the door.
3. Simultaneous doors:
A. If replacing window on the left door,
remove the handle from the front of the
door then remove door seal from the
inside edge of the door.
1) Lift out the inner door panel and
window assembly.
2) If replacing window on the right door,
remove the screws along the inside
edge (if applicable) of the door then
remove the inner door panel and
window assembly.
4. Remove the screws securing the window “tabs”
to the door bracket and lift the window
assembly out from the door frame.
5. Reverse procedure to install the replacement
window.
OVEN DOORS AND BEARINGS
(INDEPENDENT DOORS)
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Remove the top front cover and bottom front
cover as outlined under "COVERS AND
PANELS".
2. Remove the door switch lever.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001)Page 13 of 60
3. Remove the lower door seal strip to expose the
mounting screws of the door assembly.
4. Remove the two (2) lower sill bolts by the lower
door shaft and the four (4) counter-sunk screws
from the lower sill.
NOTE: The door assembly is heavy and will drop
down once the last screw is removed. If removing
door assembly with-out assistance, use caution.
5. Tilt the top of the door slightly forward and lift
the door up until the bottom of the door shaft
clears the opening in the sill.
6. Lay the door flat to prevent damage.
7. The top and bottom bearings are now
accessible for inspection and/or replacement if
needed.
A. If bearings are ok, proceed to step 8.
B. If replacing the top bearing, remove the
top bearing retainer and top bearing.
C. If replacing the bottom bearing, remove it
from the door shaft or the lower sill
opening.
8. Reverse procedure to install door assembly
and check for proper adjustment as outlined
under "DOOR ADJUSTMENT" and "DOOR
SWITCH ADJUSTMENT" in "SERVICE
PROCEDURES AND ADJUSTMENTS".
OVEN DOORS
(SIMULTANEOUS DOORS)
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
Assembly Removal
1. Remove the top front cover and bottom front
cover as outlined under "COVERS AND
PANELS".
2. Remove the door switch lever.
3. Remove the top bearing retainers and top
bearings.
4. Remove the lower door seal strip to expose the
mounting screws of the door assembly.
A. Remove the two (2) lower sill bolts by the
lower door shaft and the four (4)
counter-sunk screws from the lower sill.
NOTE: The door assembly is heavy and will drop
down once the last screw is removed. If removing
door assembly with-out assistance, use caution.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001) Page 14 of 60
5. Lift up on the door assembly and swing the
right side out then move the assembly to the
left to clear the slots in the upper door sill.
6. Lay the door assembly on a flat cushioned
surface for disassembly.
7. Reverse procedure to install door assembly
and check for proper adjustment as outlined
under "DOOR ADJUSTMENT", "DOOR CHAIN
ADJUSTMENT (SIMULTANEOUS DOORS)"
and "DOOR SWITCH ADJUSTMENT" in
"SERVICE PROCEDURES AND
ADJUSTMENTS".
Disassembly
1. Remove the door assembly as outlined in
"OVEN DOORS (SIMULTANEOUS)" under
"ASSEMBLY REMOVAL".
2. Remove the door chain by loosening one of the
turnbuckles.
3. Loosen the set screw on the sprocket of door
being replaced.
4. Drive out the spirol pin from the sprocket of
door being replaced.
5. Remove the door from lower sill bearings and
sprocket.
A. Door assembly parts are now accessible
for inspection and/or replacement if
necessary.
6. Reverse procedure to re-assemble the door
assembly parts and check for proper
adjustment as outlined under "DOOR CHAIN
ADJUSTMENT (SIMULTANEOUS DOORS)" in
"SERVICE PROCEDURES AND
ADJUSTMENTS".
DOOR CATCH ROLLER
ASSEMBLY
(INDEPENDENT DOORS)
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Remove the top front cover as outlined under
“COVERS AND PANELS”.
2. Remove the catch roller assembly.
3. Reverse procedure to install.
4. Adjust the catch roller as outlined under
“DOOR CATCH (ROLLER) ADJUSTMENT
(INDEPENDENT DOORS)”in “SERVICE
PROCEDURES AND ADJUSTMENTS”.
MECHANICAL (KX)
THERMOSTAT
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Remove the racks and right rack support.
2. Remove the thermostat knob and mounting
screws from the control panel and then remove
the control panel.
3. Remove the probe guard from the oven cavity
wall.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001)Page 15 of 60
NOTE: When installing probe guard, the probe
should not extend beyond the guard.
4. Remove the thermostat bulb from the oven
cavity by pushing it through the oven wall and
into the control panel area.
NOTE: The hole in the oven cavity wall does not
line up straight with the oven cavity outer shell,
therefore the probe must be removed at an angle.
5. Reverse the procedure to install.
6. Adjust the thermostat as outlined under
"MECHANICAL (KX) THERMOSTAT
CALIBRATION " in "SERVICE PROCEDURES
AND ADJUSTMENTS".
HIGH LIMIT THERMOSTAT
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Take out racks from the oven.
2. Remove the high limit thermostat
cover/mounting plate from inside the oven
cavity at the top.
3. Disconnect lead wires from high limit
thermostat then remove high limit thermostat
from cover/mounting plate.
NOTE: Remove the old RTV sealer from the cover
and mating surfaces inside the oven cavity and
apply new high temperature RTV sealer before
installing.
4. Reverse procedure to install.
INTERIOR LIGHTS
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
Lamp
1. Remove the racks.
2. Unscrew the glass lens for the light being
replaced then unscrew the bulb.
3. Replace bulb then reverse the procedure to
install.
Lamp Assembly
1. Remove the lens and bulb.
2. Remove the springs from the retaining tabs (2
places) on the socket.

FULL SIZE ELECTRIC CONVECTION OVEN - REMOVAL AND REPLACEMENT OF PARTS
F25105 (December 2001) Page 16 of 60
3. Depress the retaining tabs and pull the socket
out from the oven, far enough to disconnect the
lead wires.
4. Remove the socket from the oven.
5. Attach the lead wires to the replacement
socket.
6. Insert the socket into the hole in the oven and
push until the socket is held in place by the
retaining tabs.
7. Install the light bulb and lens.
8. Check for proper operation.
COOLING FAN
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
1. Remove the right side panel as outlined under
"COVERS AND PANELS".
NOTE: If right side panel is not accessible, this
component can be serviced by removing the control
panel as outlined under "COVERS AND PANELS".
2. Disconnect the lead wires to the fan motor by
removing wire nuts.
3. Remove the screws securing the air deflector
to the fan then loosen the tab screw holding the
fan to the component panel. Rotate the tab so
that the fan will clear and remove the fan.
4. Reverse the procedure to install the
replacement fan and check for proper
operation.
NOTE: The fan must be installed so air is pulled
from outside the rear of the oven and blown into the
control area. The arrow on the fan body indicates
“air flow”direction and should be pointing toward the
controls.
NOTE: Ensure fan is seated “squarely”against the
air tube and the oven bottom.
NOTE: The air deflector should be angled upwards
at approximately 30 degrees to properly direct the
air flow.

FULL SIZE ELECTRIC CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS
F25105 (December 2001)Page 17 of 60
Differential

Heat lamp OFF

Heat lamp ON
Example: 360 (
(lamp off)

340
(
(lamp on)

20
(
[Temp.(
lamp off)

Temp.( lamp on)] ÷2

Average Temp.
Example: 360
(

340
(
÷2

350
(
SERVICE PROCEDURES AND ADJUSTMENTS
WARNING: CERTAIN PROCEDURES IN THIS SECTION REQUIRE ELECTRICAL TEST OR
MEASUREMENTS WHILE POWER IS APPLIED TO THE MACHINE. EXERCISE EXTREME CAUTION AT ALL
TIMES. IF TEST POINTS ARE NOT EASILY ACCESSIBLE, DISCONNECT POWER, ATTACH TEST
EQUIPMENT AND REAPPLY POWER TO TEST.
SOLID STATE TEMPERATURE
CONTROL CALIBRATION
1. Place a thermocouple in the geometric center
of the oven cavity.
2. Set the power switch to ON.
3. Set the temperature control dial to 350 °F.
4. Allow the oven temperature to stabilize
(normally 3 cycles).
5. Record the temperature at which the Heat lamp
goes OFF and comes ON for at least two
complete heating cycles.
6. Calculate the differential by subtracting the
temperature indicated when the lamp goes out
from the temperature indicated when the lamp
comes on.
A. The differential calculated should be less
than 20 °F.
1) If the differential is 20 °F or less, the
temperature control circuit is
functioning properly.
a. Proceed to step 7.
2) If the differential is more than 20 °F:
a. Check the temperature probe as
outlined under "TEMPERATURE
PROBE TEST (SOLID STATE
CONTROL)".
b. If the probe is functioning
properly then temperature
control is malfunctioning.
a) Install a replacement
temperature control and
check calibration.
7. Calculate the average temperature by adding
the temperature indicated when the lamp goes
out to the temperature indicated when the lamp
comes on and dividing this answer by 2.
A. If the average temperature is 10 °F or
less, from the dial setting, the thermostat
is properly calibrated.
B. If the average temperature is more than
10 °F from the dial setting, the thermostat
calibration must be adjusted.
1) Loosen the temperature control knob
set screw and remove the knob from
the stem.
2) Loosen temperature control mounting
screws only enough to rotate the
control.
a. Place thumb and forefinger on
the head of the mounting
screws, apply pressure and
slightly rotate the screw heads
(body of control) in the slot.
Rotate clockwise to increase
temperature and
counterclockwise to decrease.
b. Center the stem in the opening
and re-tighten the temperature
control mounting screws.
c. Replace knob and re-tighten set
screw .

FULL SIZE ELECTRIC CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS
F25105 (December 2001) Page 18 of 60
Differential

Heat lamp OFF

Heat lamp ON
Example: 360 (
(lamp off)

340
(
(lamp on)

20
(
[Temp.(
lamp off)

Temp.( lamp on)] ÷2

Average Temp.
Example: 360
(

340
(
÷2

350
(
d. Rotate the knob to the lowest
temperature setting then back to
350°F.
e. Repeat the average temperature
calculation in step 7.
NOTE: Allow the oven to cycle
at least two times between
adjustments before performing
the calculation.
a) If the average temperature
still differs more than 10 °F
from the dial setting, adjust
the thermostat calibration
until the average
temperature is within
tolerance.
C. If the above adjustment cannot be
obtained:
1) Turn the power switch OFF.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
2) Replace the temperature control and
check calibration.
MECHANICAL (KX)
THERMOSTAT CALIBRATION
1. Place a thermocouple in the geometric center
of the oven cavity.
2. Set the power switch to ON.
3. Set the thermostat dial to 350 °F.
4. Allow the oven temperature to stabilize
(normally 3 cycles).
5. Record the temperature when the thermostat
cycles OFF and ON for at least three complete
cycles.
6. Calculate the differential by subtracting the
temperature indicated when heat lamp goes out
from temperature indicated when heat lamp
comes on.
A. The differential calculated should be less
than 30
(
F.
1) If the differential is 30 °F or less, the
thermostat is functioning properly.
a. Proceed to step 7.
2) If the differential is more than 30
(
F,
the thermostat is malfunctioning.
a. Install a replacement thermostat
and check calibration.
7. Calculate the average temperature by adding
the temperature indicated when the heat lamp
goes out to the temperature indicated when the
heat lamp comes on and dividing this answer
by 2.
A. If the average temperature is 15
(
F or less
from the dial setting, the thermostat is
properly calibrated.
B. If the average temperature is more than
15
(
F of the dial setting, the thermostat
calibration must be adjusted.
1) Remove the thermostat knob.
2) Hold the thermostat shaft and turn the
inner set screw clockwise to decrease
temperature or counterclockwise to
increase temperature (¼turn =
35
(
F).
8. Replace the knob and verify the setting is still
at 350°F.
9. Repeat step 7 until the average temperature is
within tolerance.
NOTE: Allow the oven to cycle at least two times
between adjustments before performing the
calculation.

FULL SIZE ELECTRIC CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS
F25105 (December 2001)Page 19 of 60
A. After the final adjustment is made and the
average temperature is within tolerance,
remove the knob and apply a non-
permanent type sealer around the head of
the set screw.
10. If the above adjustment cannot be obtained:
A. Turn the power switch OFF.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
B. Install a replacement thermostat and
check calibration.
SOLID STATE TEMPERATURE
CONTROL TEST
1. Remove the right side panel as outlined under
"COVERS AND PANELS" in "REMOVAL AND
REPLACEMENT OF PARTS".
NOTE: If right side panel is not accessible, this
component can be serviced by removing the control
panel as outlined under "COVERS AND PANELS".
2. Place a thermocouple in the geometric center
of the oven cavity.
NOTE: Oven temperature must be below 450°.
3. Set the temperature control to the maximum
setting.
4. Check machine data plate for correct voltage to
oven. Refer to diagram below for proper
terminal locations and voltages before
checking the control. Use the correct terminals
for the corresponding voltage.
5. Turn the power switch to ON.
6. Check for proper voltage across terminals 8 &
10 (208-240VAC) for power to the control.
A. If correct, proceed to step 7.
B. If incorrect, problem is not with the
temperature control. See
"TROUBLESHOOTING".
7. Check relay voltages on the board:
A. For 208-240VAC controls - check across
terminals 7 & 10 for input to the internal
relay and 6 & 10 for output from the
internal relay.
1) If input voltage to the internal relay is
correct, proceed to step 8. If input
voltage to the internal relay is not
present, problem is not with the
temperature control. See
"TROUBLESHOOTING".
2) If output voltage from the internal
relay is correct proceed to step 8. If
output voltage from the internal relay
is not correct, check temperature
probe as outlined under
"TEMPERATURE PROBE TEST
(SOLID STATE CONTROL)".
8. Set the temperature control to the minimum
setting.
NOTE: Oven temperature must be above 300°F.
9. Check for zero (0) volts AC across terminals 6
& 10 (208-240VAC) for no output from the
internal relay.
A. If correct, temperature control is
functioning properly.
B. If incorrect, check temperature probe as
outlined under "TEMPERATURE PROBE
TEST (SOLID STATE CONTROL)".
1) If temperature probe is ok:
a. Turn the power switch OFF.
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
b. Replace the temperature control
and check calibration as outlined
under "SOLID STATE
TEMPERATURE CONTROL
CALIBRATION".

FULL SIZE ELECTRIC CONVECTION OVENS - SERVICE PROCEDURES AND ADJUSTMENTS
F25105 (December 2001) Page 20 of 60
TEMPERATURE PROBE TEST
(SOLID STATE CONTROL)
WARNING: DISCONNECT THE ELECTRICAL
POWER TO THE MACHINE AT THE MAIN
CIRCUIT BOX. PLACE A TAG ON THE CIRCUIT
BOX INDICATING THE CIRCUIT IS BEING
SERVICED.
NOTE: The temperature probe used in conjunction
with the Solid State Temperature control is an RTD
(resistance temperature detector) of the Thermistor
type. As temperature increases the resistance value
decreases.
1. Remove the right side panel as outlined under
"COVERS AND PANELS" in "REMOVAL AND
REPLACEMENT OF PARTS".
NOTE: If right side panel is not accessible, this
component can be serviced by removing the control
panel as outlined under "COVERS AND PANELS".
2. Place a shielded thermocouple in the geometric
center of the oven cavity and determine the
temperature in the oven cavity.
3. Remove the probe lead wires from the solid
state temperature control.
4. Test the probe with an ohmmeter.
A. If the measured resistance values are
inside the given tolerance then the probe
is functioning properly.
B. If the measured resistance values are
outside the given tolerance then replace
the probe and retest.
1) Check oven for proper operation.
5. Reverse procedure to install.
TEMP (°F) OHMS* TEMP (°F) OHMS*
77 90,000 360 822
240 4,077 380 656
260 3,016 400 529
280 2,266 425 424
300 1,726 450 334
320 1,332 475 266
340 1,041
(*) Resistance in ohms ± 10%
HEATING ELEMENT TEST
WARNING: THE FOLLOWING STEPS REQUIRE
POWER TO BE APPLIED TO THE UNIT DURING
THE TEST. USE EXTREME CAUTION AT ALL
TIMES.
1. Turn the power switch ON and set the oven
temperature control to the highest setting.
2. Measure the voltage at the heating element
terminals and verify it against the data plate
voltage.
A. If voltage is incorrect, find the source of
the problem.
B. If voltage is correct, check current draw
(amps) through the heating element lead
wires.
NOTE: This method is preferred over a
resistance check when a clamp on type amp
meter is available.
1) If current draw is correct then heating
element is functioning properly. See
table below for proper values.
2) If current draw is not correct, turn the
power switch OFF and disconnect
the electrical supply to the oven.
a. Replace heating element then
proceed to step 3.
C. If unable to check current draw, a
resistance check may indicate a
malfunctioning element.
1) Turn the power switch OFF and
disconnect the electrical supply to
the oven.
2) Remove the lead wires from the
heating element and check resistance
(ohms). See table below for proper
values.
3. Check for proper operation.
VOLTAGE KW PER
ELEMENT
AMPS PER
ELEMENT
LEAD OHMS PER
ELEMENT
1 PH 3 PH
208 2603521
240 2523328
480 2 15 4 111
NOTES: 1. Values in the table are nominal.
Tolerance is +5/-10%.
2. Voltage values are @ 60HZ.
3. Resistance values (ohms) are @
room temperature.