Vulcan-Hart SG4D ML-114875 User manual

– 1 –
Model SG4D
SERVICE MANUAL
SG4 & SG6 SERIES
FULL SIZE GAS
CONVECTION OVENS
MODELS
SG4D ML-114875
SG4C ML-114876
SG6D ML-114877
SG6C ML-114878
VULCAN-HART COMPANY, P.O. BOX 696, LOUISVILLE, KY 40201-0696, TEL. [phone]
FORM 31192 (Jan. 2002)
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 PROCEDURES DESCRIBED IN THIS MANUAL.
THIS MANUAL IS NOT INTENDED TO BE ALL ENCOMPASSING. IF YOU HAVE NOT ATTENDED
A VULCAN SERVICE SCHOOL FOR THIS PRODUCT, 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-HART COMPANY, IS PROHIBITED.

–2 –
© VULCAN-HART COMPANY, 2002

–3 –
TABLE OF CONTENTS
GENERAL .............................................................................................................................................................. 5
Introduction ............................................................................................................................................... 5
Installation ................................................................................................................................................ 5
Operation................................................................................................................................................... 5
Cleaning .................................................................................................................................................... 5
Lubrication................................................................................................................................................. 5
Specifications ........................................................................................................................................... 5
Electrical Data .................................................................................................................................... 5
Gas Data............................................................................................................................................. 5
Tools ......................................................................................................................................................... 5
Standard ............................................................................................................................................. 5
Special ................................................................................................................................................ 5
REMOVAL AND REPLACEMENT OF PARTS ..................................................................................................... 6
Component Location ................................................................................................................................. 6
Covers and Panels ................................................................................................................................... 7
Top Front Cover.................................................................................................................................. 7
Bottom Front Cover ............................................................................................................................ 7
Control Panel ...................................................................................................................................... 7
Right Side Panel................................................................................................................................. 7
Control Panel Components ....................................................................................................................... 8
Procedure ........................................................................................................................................... 8
Component Panel Components ................................................................................................................ 9
Procedure ........................................................................................................................................... 9
Temperature Probe ..................................................................................................................................10
Gas Burners .............................................................................................................................................11
Gas Orifice ...............................................................................................................................................12
Gas Solenoid Valve .................................................................................................................................12
Ignition Control Module ............................................................................................................................13
Spark Igniter and Flame Sense ...............................................................................................................13
Blower and Motor .....................................................................................................................................14
Oven Doors and Bearings........................................................................................................................15
Door Catch Assembly ..............................................................................................................................16
Door Window ............................................................................................................................................16
Door Switch..............................................................................................................................................17
High Limit Thermostat .............................................................................................................................17
Interior Lights ...........................................................................................................................................18
Lamp Assembly.................................................................................................................................19
Cooling Fan ..............................................................................................................................................19
Fan Installation Tips..........................................................................................................................19
SERVICE PROCEDURES AND ADJUSTMENTS ...............................................................................................20
Solid State Temperature Controller Calibration (SG4D/SG6D)...............................................................20
Calibration Steps ...............................................................................................................................20
Calibration Tips..................................................................................................................................20
Solid State Temperature Controller Test (SG4D/SG6D).........................................................................21
Test Steps .........................................................................................................................................21
Temperature Probe Test (SG4D/SG6D) ..................................................................................................22
Test Steps .........................................................................................................................................22

–4 –
TABLE OF CONTENTS (Cont.)
Computer Controller (SG4C/SG6C) .........................................................................................................23
Operation ...........................................................................................................................................23
Setup Mode .......................................................................................................................................23
Probe Test .........................................................................................................................................23
Solid State Relay Test ......................................................................................................................24
Computer Controller Calibration (SG4C/SG6C).......................................................................................24
Calibration Steps ...............................................................................................................................24
Gas Pressure Adjustment .......................................................................................................................25
Verification of Spark at Igniter ................................................................................................................26
Door Switch Adjustment ..........................................................................................................................26
Blower Adjustment ...................................................................................................................................27
Door Adjustment ......................................................................................................................................28
Door Catch Roller Adjustment .................................................................................................................29
ELECTRICAL OPERATION .................................................................................................................................30
Component Description ...........................................................................................................................30
Plug, Socket and Components (SG4D/SG6D)........................................................................................31
Plug, Socket and Components (SG4C/SG6C)........................................................................................32
Sequence of Operations ..........................................................................................................................33
SG4D/SG6D with Solid State Temperature Controller .....................................................................33
Cook Cycle ........................................................................................................................................33
Timer Cycle .......................................................................................................................................34
Cool Down Cycle (Solid State Temperature Controller) ...................................................................34
SG4C/SG6C with Computer Controller .............................................................................................35
Normal Cook Cycle .....................................................................................................................35
Temperature and Time Cycle (Normal Cooking)...............................................................................37
Function Switch (SG4C/SG6C) .........................................................................................................37
Roast and Hold Cycle........................................................................................................................37
Wiring Diagrams .......................................................................................................................................38
Schematics ..............................................................................................................................................40
TROUBLESHOOTING ..........................................................................................................................................42
Error Codes ..............................................................................................................................................44

–5 –
INSTALLATION
Generally, installations are made by the dealer or
contractedbythedealeror owner. Detailed installation
instructionsareincludedintheInstallation&Operation
Manual which is sent with each unit.
OPERATION
Detailed operation instructions are included with each
oven.
CLEANING
Detailed cleaning procedures are included in the
Installation & Operation Manual for the appropriate
model.
LUBRICATION
Motor bearings are sealed and prelubricated.
SPECIFICATIONS
Electrical Data
INTRODUCTION
GENERAL
Gas Data
TOOLS
Standard
•Hand tools (standard set).
•VOM with AC current tester (any quality VOM
with a sensitivity of at least 20,000 ohms per
volt can be used).
•Gear puller to remove blower.
Special
•Temperature tester (thermocouple type).
•Manometer
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. All models are equipped with a two-speed 1/2 HP electric
motor, porcelain interior and two 30,000 BTU/hr burners as standard equipment. A power level control permits
variable burner input from 15,0000 BTU/hr to 60,000 BTU/hr.
Models SG4D and SG6D are equipped with solid state-controls and a 60-minute timer (a 5-hour timer is optional).
Models SG4C and SG6C have a computer control with built-in Roast & Hold.
Models SG6D and SG6C have a 4" deeper cavity than models SG4D and SG4C.
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–6 –
REMOVAL AND REPLACEMENT OF PARTS
COMPONENT LOCATION
DOOR
SWITCH
IGNITER &
FLAME SENSE
GAS BURNERS COMPONENT
PANEL
COOLING
FAN
OVEN LIGHTS
CONTROL
PANEL
TOP VIEW
BLOWER MOTOR
TEMPERATURE PROBE
HIGH LIMIT
GAS VALVE
PL-56044

–7 –
COVERS AND PANELS
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
Top Front Cover
1. The top front cover is secured with four
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 six
screws, two on each side of cover and two on
the top. Remove these screws then remove
the cover from the oven.
2. Reverse the procedure to install.
Control Panel
1. Remove three screws on the right side which
secure the control panel. Pull the panel away
from the oven.
2. Disconnect the temperature probe leads from
the solid state temperature controller.
3. Unplug the wire harness connector to the
control panel components.
4. Reverse the procedure to install.
Right Side Panel
1. Remove the screws that secure the right side
of the control panel.
2. Remove the remaining 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.
RIGHT SIDE
RIGHT SIDE
REMOVE
REMOVE
SCREWS
SCREWS
PL-56043
TOP FRONT COVER
REMOVE SCREWS
PL-56040
OFF
OVEN
COOL
MASTER SWITCH
ON
HEAT
IGNITION
REMOVE
SCREWS
CONTROL
PANEL
ON
HI
OFF
LOW
LIGHTS
FAN SPEED
SG4D SHOWN
THERMOSTAT
POWERLEVEL
OFF
OVEN
COOL
MASTER SWITC H
PL-56042
BOTTOM FRONT COVER
BOTTOM FRONT COVER
REMOVE SCREWS
REMOVE SCREWS
PL-56041

–8 –
CONTROL PANEL COMPONENTS
Procedure
WARNING: DISCONNECT(UNPLUG)ELECTRICALPOWERSUPPLYANDPLACE A TAG AT THE DISCONNECT
SWITCH INDICATING YOU ARE WORKING ON THE CIRCUIT.
1. Remove the control panel as outlined under Covers and Panels.
2. Remove the component being replaced.
3. Reverse the procedure to install the new component, then check oven for proper operation.
MASTER
SWITCH
SG4D/SG6D
PL-56045
OFF
THERMOSTAT
55
50
45
40
35
30
0
25
TIMER
55
50
45
40
35
30
0
25
HI
FAN SPEED
LOW
ON
LIGHTS
OFF
OFF
OVEN
COOL ON
MASTER SWITCH
POWERLEVEL
ON/HEAT
INDICATOR
LIGHTS
NO IGNITION
LIGHT
TEMPERATURE
CONTROLLER
(THERMOSTAT)
POWER LEVEL
LIGHT
POWER CONTROL
TIMER
LIGHT
SWITCH
FAN SPEED
SWITCH
SG4C/SG6C
ON
OFF
POWER
OVEN
COOL
ON
LIGHTS
OFF
LIGHT
SWITCH
POWER
SWITCH
NO IGNITION
LIGHT
COMPUTER
CONTROLLER
PL-56046

–9 –
COMPONENT PANEL COMPONENTS
Procedure
WARNING: DISCONNECT(UNPLUG)ELECTRICALPOWERSUPPLYANDPLACE A TAG AT THE DISCONNECT
SWITCH INDICATING YOU ARE WORKING ON THE CIRCUIT.
1. Remove the right side 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 new component and check oven for proper operation.
PL-56047
IGNITION
MODULE
IGNITION
MODULE
BOARD
HEATING
RELAY
PORCELAIN
BLOCK
ASSEMBLY
PORCELAIN
BLOCK
ASSEMBLY
SG4D/SG6D
TRANSFORMER
MOTOR
CONTROL
RELAYS
IGNITION
MODULE
BOARD
IGNITION
MODULE
PORCELAIN
BLOCK
ASSEMBLY
HEATING
RELAY
PORCELAIN
BLOCK
ASSEMBLY
SG4C/SG6C
TRANSFORMER
PL-56048

–10 –
TEMPERATURE PROBE
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
1. Remove the right-side panel as outlined under
Covers and Panels.
2. Disconnect probe leads from the solid state
temperature controller on the SG4D/SG6D or
the computer controller on the SG4C/SG6C.
3. Remove the racks and right rack support.
4. Remove the upper and lower door seals.
5. Loosen the three screws securing the right
side air scoop to the rear heat exchanger.
Rotate the air scoop off of the heat exchanger
tube into the oven cavity.
6. Remove the screws that secure the perforated
side panel and lift out.
7. Remove the probe from the bracket(s).
SG4C/SG6C Temperature Probe Shown
8. Push the probe through the oven wall and into
the control panel area.
9. Reverse the procedure to install the new
probe.
10. Calibration:
A. SG4D/SG6D: Adjust the temperature
controller as outlined under Solid State
Control Calibration.
B. SG4C/SG6C: Adjust the computer
controller as outlined under Computer
Controller and/or Computer Controller
Calibration in Service Procedures and
Adjustments.

–11 –
GAS BURNERS
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
WARNING: SHUT OFF THE GAS BEFORE
SERVICING THE OVEN.
1. Remove the lower front cover as outlined
under Covers and Panels.
2. There are two burners located on the bottom
left and right side of the oven. Disconnect the
ignition cable and the flame sense lead from
each burner.
3. Remove the bolts securing the gas manifold
and place manifold aside.
4. Grasp the burner and lift out.
5. Reverse the procedure to install and check
for proper operation.
A. Ensure the spacers are in place on the
ignition wires. The spacers are intended
to keep the ignition wires from laying flat
on the oven chassis.
B. Ensure that the bracket on the back of
the burner is inserted into the slot at the
rear of the burner chamber.

–12 –
GAS ORIFICE
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
WARNING: SHUT OFF THE GAS BEFORE
SERVICING THE OVEN.
1. Remove the lower front cover as outlined
under Covers and Panels.
2. Remove the bolts securing the gas manifold
and place manifold aside.
3. There are two gas orifices on the manifold.
Remove each orifice and replace with the
correctorifice for the given altitude as needed.
4. Reverse the procedure to install manifold and
check for proper operation.
GAS SOLENOID VALVE
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
WARNING: SHUT OFF THE GAS BEFORE
SERVICING THE OVEN.
1. Remove the control panel and the right side
panel as outlined under Covers and Panels.
2. Disconnect the lead wires.
3. Disconnect compression fittings from the
valve.
4. Loosen the bolts securing the valve and
bracket assembly, then remove the screws
securing the valve to the bracket.
5. Reverse the procedure to install the
replacement gas valve.
WARNING:ALLGASJOINTSDISTURBEDDURING
SERVICING MUST BE CHECKED FOR LEAKS.
CHECK WITH SOAP AND WATER SOLUTION
(BUBBLES). DO NOT USE AN OPEN FLAME.
6. Verify gas pressure as outlined under the
Gas Pressure Adjustment in Service
Procedures and Adjustments. Check for
proper operation.

–13 –
IGNITION CONTROL MODULE
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
1. Remove the right side cover as outlined
under Covers and Panels.
2. Loosen the screws securing the mounting
bracket to the component panel and remove
the bracket.
3. Disconnect the lead wires and igniter cables
from the ignition module board.
4. Remove the ignition module board from the
mounting bracket.
5. Reverse the procedure to install the
replacement ignition module board.
6. Check for proper operation.
SPARK IGNITER AND FLAME SENSE
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
WARNING: SHUT OFF THE GAS BEFORE
SERVICING THE OVEN.
1. Remove the two gas burners as outlined
under Gas Burners.
2. Remove the screws securing the igniter and
flame sense to each burner. Remove the
assembly.
3. The spark gap is 1/8" from the inside of the
spark rod to the inside to the ground rod. The
ground rod (the end of the spark) is 1/8" above
the burner. If the gap is not correct or poor
sparkingis occurring, then adjust accordingly.
4. Reverse the procedure to install the assembly
and check for proper operation.

–14 –
BLOWER AND MOTOR
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
1. Remove racks.
2. Remove the screws securing the snorkel and
remove the snorkel.
3. Remove screws securing baffle panel and
remove the panel.
4. If replacing:
A. Blower Only - Loosen set screws on
blower hub and using a bearing puller,
remove blower from motor shaft.
1) Reverse procedure to install and
adjust blower position as outlined
under the Blower Adjustment in
ServiceProceduresand Adjustments
section.
B. Motor - Perform step 4A and continue
procedure.
5. Remove the screws that secure the motor
mounting plate to the rear wall.
6. Place a piece of cardboard on the bottom of
the oven cavity to protect its surface from
any damage during motor assembly removal.
7. Pull the motor assembly into the oven cavity
and place it on the cardboard.
8. Remove the junction box cover from the
motor, disconnect lead wires and remove the
conduit.
9. Remove motor mounting bolts and flat
washers, then lift the motor from the mounting
plate.
10. Position the replacement motor on the motor
mounting plate and install mounting bolts and
washers. Hand tighten mounting bolts only.
11. Reconnect to lead wires at the motor, and
replace conduit and junction box cover.

–15 –
12. Slide blower onto motor shaft until hub is
flush with end of shaft, then tighten setscrews.
13. Adjust motor position until blower is parallel
to motor mounting plate as outlined in Blower
Adjustment under Service Procedures and
Adjustments.
14. Position motor mounting plate on the rear
wall and secure with nuts and washers.
15. Replace the baffle panel and snorkel.
16. Replace the air baffle on the rear wall at the
lower right hand corner.
17. Remove cardboard from the bottom of the
oven cavity.
18. Install racks.
19. Check oven for proper operation.
OVEN DOORS AND BEARINGS
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
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 lower door seal strip to expose
the mounting screws of the door assembly.
4. Remove the two lower sill bolts by the lower
door shaft and the four countersunk screws
from the lower sill.
A. The door assembly is heavy and will drop
down once the last screw is removed. If
removing the door assembly without
assistance, the ignition cable, flame
sense lead and gas manifold should also
be removed to avoid damage to these
components.
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.
PL-56051
MOTOR ROTATES CLOCKWISE
FRONT VIEW OF MOTOR
FROM INSIDE OVEN CAVITY

–16 –
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 operation as outlined
under the Door Adjustment and Door Switch
Adjustment section in Procedures and
Adjustments.
DOOR CATCH ASSEMBLY
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
1. Remove the top front cover as outlined under
Covers and Panels.
2. Remove the nuts and bolts that secure the
door catch assembly.
3. Reverse the procedure to install.
4. Adjust the roller catch as outlined under the
DoorCatchAdjustmentinServiceProcedures
and Adjustments.
DOOR WINDOW
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
1. Remove the screws at the top and bottom of
the door.
2. Remove the door handle, then remove the
outer door panel.
3. Lift out the inner door panel window assembly.
4. Remove the door seal from the inside of the
left door only.
5. Remove the screws securing the window
tabs to the door bracket and lift the window
assembly out from the door frame.
6. Reverse procedure to install the replacement
window.
GLASS
REMOVE
SCREWS
OVEN CAVITY
PL-56052
GLASS
GLASS
REMOVE
SCREWS
INNER DOOR PANEL ASSEMBLY
PL-56053

–17 –
DOOR SWITCH
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
1. Remove the top front cover as outlined under
Covers and Panel.
2. Disconnect the lead wires to the door switch.
3. Remove the switch.
4. Reverse procedure to install the replacement
switch and check for proper adjustment as
outlined in Door Switch under Service
Procedures and Adjustments.
HIGH LIMIT THERMOSTAT
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
1. Remove the top four racks from the oven.
2. Remove the high limit thermostat cover/
mounting plate. It is located at the top of the
oven cavity.

–18 –
3. Disconnect the lead wires from the high limit
thermostat. Remove the high limit thermostat
from the cover mounting plate.
4. Remove the old RTV silicone from the cover
and mating surfaces inside the oven cavity,
and apply new RTV silicone before installing.
5. Reverse procedure to install.
INTERIOR LIGHTS
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
1. Remove the racks from the oven.
2. Unscrew the glass lens for the light being
replaced, then unscrew the bulb.
3. Replace bulb, then reverse the procedure to
install.
LENS
LENS
OVEN CAVITY
PL-56054

–19 –
COOLING FAN
WARNING: DISCONNECT(UNPLUG)ELECTRICAL
POWER SUPPLY AND PLACE A TAG AT THE
DISCONNECT SWITCH INDICATING YOU ARE
WORKING ON THE CIRCUIT.
1. Remove the right side panel as outlined
under Covers and Panels.
2. Disconnect the lead wires to the fan motor by
removing the 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. Remove the fan.
4. Reverse the procedure to install the
replacement fan and check for proper
operation.
Fan Installation Tips
•The fan must be installed so air is pulled from
the rear of the oven and blown into the control
area. The arrow on the fan body indicates
airflowdirectionandshouldbepointingtoward
the controls.
•Ensure the fan is seated squarely against the
air tube and the oven bottom.
•The air deflector should be angled upward at
approximately 30 degrees to properly direct
the airflow.
Lamp Assembly
1. Remove the lens and bulb.
2. Remove the springs from the retaining tabs
(two places) on the socket.
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. Ensure the case is connected to the green
ground wire.
8. Check for proper operation.
RETAINING TABS
SPRING
CROSS SECTIONAL VIEW PL-56055

–20 –
SOLID STATE TEMPERATURE
CONTROLLER CALIBRATION
(SG4D/SG6D)
Calibration Steps
1. Place a thermocouple in the geometric center
of the oven cavity.
2. Set the ON/OFF/OVEN COOL switch to ON.
3. Set the temperature controller dial to 350°F.
Set the power control to 100%.
4. Allow the oven temperature to stabilize
(minimum three heating cycles).
5. Record the temperature at which the Heat
lamp goes ON and comes OFF 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.
Differential = Heat lamp ON - Heat lamp OFF.
A. The differential calculated should be less
than 20°F.
1) If the differential is less than 20°F,
the temperature control circuit is
functioning properly. Proceed to step
7.
2) If the differential is more than 20°F,
check the temperature probe as
outlined under Temperature Probe
Test (SG4D/SG6D).
3) If the probe is functioning properly,
then temperature controller is
malfunctioning. Install a replacement
temperature controller and check
calibration.
7. Calculate the average temperature by adding
the temperature indicated when the lamp is
on to the temperature indicated when the
lamp goes out and dividing the answer by 2.
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, DISCERN POWER, ATTACH TEST EQUIPMENT AND REAPPLY
POWER TO TEST.
Average Temp = Heat lamp ON + Heat lamp OFF
2
A. If the average temperature is within 10°F
fromthedialsetting,thethermostatisproperly
calibrated.
B. If the average temperature is more than 10°F
fromthedialsetting,thethermostatcalibration
must be adjusted.
1) Loosen the temperature controller knob
set screw and remove the knob from the
stem.
2) Loosen temperature controller 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
retighten the temperature controller
mounting screws.
c. Replaceknob and retightensetscrew.
d. Rotate the knob to the lowest
temperature setting then back to
350°F.
e. Repeat the average temperature
calculation in step 7.
C. If the above adjustment cannot be obtained,
replace the temperature controller and check
calibration.
Calibration Tips
Allow the oven to cycle at least three times between
adjustments before performing the calculation.