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ELECTRICAL OPERATION

COMPONENT DESCRIPTION

Master Switch (S1)

 - Determines the mode of

operation; ON, OFF or OVEN COOL

Lights Switch (S2)

 - Controls the oven cavity lights.

Fan Speed Switch Hi/Low (S3)

 - Controls blower

motor speed between HI and LOW settings. Available
on models SG4D/SG6D.

Alarm/Buzzer

 - Signals the end of the normal cook

cycle when cooking time expires.

Timer

 - Times the cooking cycle and signals the

buzzer at the end of the cycle.

Door Switch

 - Allows the oven to operate when the

doors are closed but stops the oven from operating
when the doors are opened.

Blower Motor

 - Operates the oven cavity blower.

Also, an internal centrifugal switch on the motor is
utilized to allow the connection of power to the heat
relay when the motor is at operating speed.

Transformer (T1)

 - Provides 24 VAC power to the

ignition control module and heating circuit.

Motor Control Relay(s) (SG4C/SG6C)

 - Provides

power to HI and LOW speed motor windings based on
operator requirements.

Solid State Temperature Controller (SG4D/SG6D)

- Monitors temperature sensor and regulates the oven
cavity temperature by controlling the heat relay
through the blower motor centrifugal switch contacts.

Ignition Control Module

 - Provide ignition spark and

monitors burner(s) flame current during ignition
sequence.

Ignition Electrode and Flame Sense Device

 -

Ignites the gas and senses the presence of a flame.
The flame presence generates a micro-amp flame
sense current that is monitored by the ignition control
module. A flame sense current of 1 micro amp
(minimum and stable) is required to maintain burner
ignition.

Power On Light (SG4D/SG6D)

 - Lit whenever the

Master Switch (S1) is turned to ON or OVEN COOL
mode.

Heat Light

 - Lit whenever temperature controller is

calling for heat.

No Ignition Light (SG4C/SG6C)

 - Lit when power is

turned ON, during ignition trial and gas purge time and
when no flame is detected by flame sensor. If the oven
fails to ignite after three attempts, it will remain lit until
power is reset.

Temperature Probe (SG4D/SG6D)

 - This

temperature probe is a thermistor device. A thermistor
is a calibrated resistor which changes resistance with
the temperature. As the temperature increases, the
resistance of the thermistor decreases. The
resistance of the probe is compared to the resistance
of the temperature controller resistor in to control and
maintain temperature.

Temperature Probe (SG4C/SG6C)

 - This

temperature probe is a J-type thermocouple. As the
temperature increases, a DC voltage is generated
within this thermocouple and compared to a list of
temperature values stored within the cooking
computer memory to control and maintain
temperature.

High Limit Thermostat

 - Protects the oven from

temperatures above 550°F by removing power from
the first valve (safety) on the dual solenoid gas valve
which stops the flow of gas to the burner. Auto resets
at 500°F.

Gas Valve (Dual Solenoid)

 - Contains two valves.

The first valve is opened when the unit is turned on
and the limit temperature is not exceeded. The second
valve is turned by the heating system. Both valves
must be open in order to get gas to the main burners.

SSR1 and SSR2 (SG4C/SG6C)

 - When SSR1 is

energized, it connects power to the blower motor for
HI fan speed operation. When SSR2 is energized, it
connects power to blower motor for LOW speed
operation.

Cooling Fan

 - Circulates cooler air from rear of oven

forward to cool components in the control area.

Computer Control (SG4C/SG6C)

 - Monitors

temperature sensor and regulates the oven cavity
temperature by controlling the heat relay (R1) through
the blower motor centrifugal switch contacts. Also,
counts the time of the product and signals the
electronic alarm at the end of the cook cycle.

Power Level Control

 - Selects the percent of heat

input between 22% and 100%. Power level must be
on for oven to work.

SG4 & SG6 Series Full Size Gas Convection Ovens - ELECTRICAL OPERATION

F35626 Rev. B (1118)

Page 38 of 56

Summary of Contents for ML-114875

Page 1: ...truments 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 The rep...

Page 2: ...ENDENT DOORS 19 DOOR CATCH ROLLER ASSEMBLY INDEPENDENT DOORS 20 DOOR WINDOW 20 INTERIOR LIGHTS REAR MOUNTED ROUND 21 INTERIOR LIGHTS SIDE MOUNTED SQUARE 21 DOOR SWITCH 23 HIGH LIMIT THERMOSTAT 24 COOL...

Page 3: ...TROUBLESHOOTING 53 TROUBLESHOOTING 53 IGNITION MODULE DIAGNOSTICS 55 SG4 SG6 Series Full Size Gas Convection Ovens VULCAN 2018 Page 3 of 56 F35626 Rev B 1118...

Page 4: ...NDENT DOORS Starting at Serial Number 481907146 INTERIOR LIGHTS Rear Mounted Round INTERIOR LIGHTS Side Mounted Square FLAME SENSE CURRENT TEST DOOR ADJUSTMENT WIRING DIAGRAMS SCHEMATICS COMPONENT DES...

Page 5: ...he dealer or owner Detailed installation instructions are included in the Installation Operation Manual which is sent with each unit OPERATION Detailed operation instructions are included with each ov...

Page 6: ...he machine and follow lockout tagout procedures 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 Fig...

Page 7: ...oven Fig 4 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...

Page 8: ...CONTROL PANEL COMPONENTS Fig 6 SG4 SG6 Series Full Size Gas Convection Ovens REMOVAL AND REPLACEMENT OF PARTS F35626 Rev B 1118 Page 8 of 56...

Page 9: ...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 SG4 SG6 S...

Page 10: ...COMPONENT PANEL COMPONENTS Fig 8 SG4 SG6 Series Full Size Gas Convection Ovens REMOVAL AND REPLACEMENT OF PARTS F35626 Rev B 1118 Page 10 of 56...

Page 11: ...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 pro...

Page 12: ...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 contro...

Page 13: ...he electrical power to the machine and follow lockout tagout procedures Shut off the gas before servicing the oven 1 Remove the lower front cover as outlined under Covers and Panels 2 Remove the bolts...

Page 14: ...ed under the Gas Pressure Adjustment in Service Procedures and Adjustments Check for proper operation IGNITION CONTROL MODULE Disconnect the electrical power to the machine and follow lockout tagout p...

Page 15: ...the end of the spark is 1 8 above the burner If the gap is not correct or poor sparking is occurring then adjust accordingly Fig 24 4 Reverse the procedure to install the assembly and check for proper...

Page 16: ...ion 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 b...

Page 17: ...move RIGHT SIDE PANEL S 2 Disconnect motor harness 1 Fig 28 Fig 28 3 Pinch cord grip together to remove from rear panel Fig 29 4 Push motor wiring harness cord out hole in rear panel 5 Remove racks 6...

Page 18: ...g 33 13 Reverse procedure to install 14 Verify operation OVEN DOORS AND BEARINGS Ending at Serial Number 481907145 Disconnect the electrical power to the machine and follow lockout tagout procedures 1...

Page 19: ...mbly and check for proper operation as outlined under the Door Adjustment and Door Switch Adjustment section in Procedures and Adjustments OVEN DOORS INDEPENDENT DOORS Starting at Serial Number 481907...

Page 20: ...t secure the door catch assembly Fig 40 3 Reverse the procedure to install 4 Adjust the roller catch as outlined under the Door Catch Adjustment in Service Procedures and Adjustments DOOR WINDOW Disco...

Page 21: ...machine and follow lockout tagout procedures Lamp Assembly 1 Remove lens and bulb 2 Remove springs from retaining tabs 2 places on the socket Fig 44 3 Depress retaining tabs and pull socket out from...

Page 22: ...6 is flat on lamp cover and not damaged Fig 46 Lamp Assembly Replacement Disconnect the electrical power to the machine and follow lockout tagout procedures 1 Remove racks 2 Remove BULB if reusing 3 L...

Page 23: ...damaged Fig 49 DOOR SWITCH Disconnect the electrical power to the machine and follow lockout tagout procedures 1 Remove the top front cover as outlined under Covers and Panel 2 Disconnect the lead wi...

Page 24: ...er mounting plate Fig 52 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 COOLING FAN...

Page 25: ...he control area The arrow on the fan body indicates airflow direction and should be pointing toward the controls Ensure the fan is seated squarely against the air tube and the oven bottom The air defl...

Page 26: ...e B For 208 240 VAC controls check across terminals J3 and J9 for input voltage and between J9 and J5 for output voltage from the internal switching device 1 If input voltage is correct proceed to ste...

Page 27: ...ll a new temperature controller and run calibration steps again 7 Calculate the average oven temperature by adding the actual minimum temperature to the actual maximum temperature and dividing by 2 EX...

Page 28: ...re in the oven cavity 3 Remove the probe lead wires from the solid state temperature controller 4 Test the probe with an ohmmeter A If the measured resistance values are inside the given tolerance the...

Page 29: ...nput Type 1 InP1 J Range Low 1 rL1 75 Range High 1 rH1 500 Hysteresis HYS1 3 Calibration Offset CAL1 0 Exit setup mode and return to operation mode Set point temperature is displayed or if calling for...

Page 30: ...l CAL1 calibration offset appears 1 If the thermocouple reading is higher than set point temperature press the down arrow key and enter a negative offset value that is equal to the number of degrees a...

Page 31: ...SURE READINGS IN W C MANIFOLD LINE RECOMMENDED MIN MAX Nat 3 5 7 0 5 0 14 Prop 10 11 0 11 0 NOTE Nat Natural Gas Prop Propane VERIFICATION OF SPARK AT IGNITOR Certain procedures in this section requir...

Page 32: ...ion cable to the oven frame should be observed DOOR SWITCH ADJUSTMENT Certain procedures in this section require electrical test or measurements while power is applied to the machine Exercise extreme...

Page 33: ...e 4 Remove top screw and loosen bottom screw securing the ignition control module mounting bracket Fig 62 5 Position bracket horizontally by pulling forward 90 degrees with ignition module facing up f...

Page 34: ...and the burner does not light and maintain flame replace ignition module If Micro Amp reading is NOT correct check wiring from flame sensor igniter to the ignition module If wiring is ok replace flam...

Page 35: ...o install Use locktight on mounting nuts and bolts DOOR STRIKE ADJUSTMENT INDEPENDENT DOORS Certain procedures in this section require electrical test or measurements while power is applied to the mac...

Page 36: ...d replace if it is damaged 4 Check for proper door alignment A Doors should be centered in the cavity opening and parallel to top and bottom of oven as outlined under Door Adjustment 5 With the door i...

Page 37: ...Fig 69 Figure shown below Left Side is starting at Serial Number 481907146 Fig 70 4 Move the door until proper alignment is achieved then tighten the screws bolts on the upper door bearing hardware 5...

Page 38: ...n no flame is detected by flame sensor If the oven fails to ignite after three attempts it will remain lit until power is reset Temperature Probe SG4D SG6D This temperature probe is a thermistor devic...

Page 39: ...Plug Socket and Components SG4D SG6D Fig 71 SG4 SG6 Series Full Size Gas Convection Ovens ELECTRICAL OPERATION Page 39 of 56 F35626 Rev B 1118...

Page 40: ...Plug Socket and Components SG4C SG6C Fig 72 SG4 SG6 Series Full Size Gas Convection Ovens ELECTRICAL OPERATION F35626 Rev B 1118 Page 40 of 56...

Page 41: ...STARTING AT SERIAL NUMBER 481913936 STANDARD SG4 SG6 Series Full Size Gas Convection Ovens ELECTRICAL OPERATION Page 41 of 56 F35626 Rev B 1118...

Page 42: ...RATIONS SG4D SG6D with Solid State Temperature Controller Schematic 424373 1 will be used to explain the electrical sequence of operation Cook Cycle 1 Conditions SG4 SG6 Series Full Size Gas Convectio...

Page 43: ...ve energized Gas does not flow to the burner until the 2nd valve main is energized 3 Ignition module energized E Heating light is lit F Power to one side of centrifugal switch G Convection fan motor i...

Page 44: ...onents heat relay R3 normally open N O contacts high limit connected through the normally closed N C contacts to the first valve safety on the dual solenoid gas valve a First valve safety on the gas v...

Page 45: ...activated and SSR1 relay is energized a Convection fan motor is energized fan speed on HI 3 When the convection fan motor reaches operating speed a The blower switch N O on the motor closes B Heat rel...

Page 46: ...the control comes ON 2 Convection fan speed changes from HI to LO A The computer control 5 VDC output from pins C2 2 and C2 8 is deactivated and SSR1 relay is de energized 1 Power 120 VAC is removed...

Page 47: ...WIRING DIAGRAMS Fig 75 SG4 SG6 Series Full Size Gas Convection Ovens ELECTRICAL OPERATION Page 47 of 56 F35626 Rev B 1118...

Page 48: ...STARTING AT SERIAL NUMBER 481913936 SG4 SG6 Series Full Size Gas Convection Ovens ELECTRICAL OPERATION F35626 Rev B 1118 Page 48 of 56...

Page 49: ...Fig 77 SG4 SG6 Series Full Size Gas Convection Ovens ELECTRICAL OPERATION Page 49 of 56 F35626 Rev B 1118...

Page 50: ...SCHEMATICS Fig 78 SG4 SG6 Series Full Size Gas Convection Ovens ELECTRICAL OPERATION F35626 Rev B 1118 Page 50 of 56...

Page 51: ...Fig 79 SG4 SG6 Series Full Size Gas Convection Ovens ELECTRICAL OPERATION Page 51 of 56 F35626 Rev B 1118...

Page 52: ...STARTING AT SERIAL NUMBER 481913936 SG4 SG6 Series Full Size Gas Convection Ovens ELECTRICAL OPERATION F35626 Rev B 1118 Page 52 of 56...

Page 53: ...ter flame sense Igniter cable high voltage OPEN Heat relay malfunction Centrifugal switch in blower motor inoperative Transformer inoperative High limit thermostat open Interconnecting wiring malfunct...

Page 54: ...problems High ambient temperatures Wiring connections loose Cooling fan malfunction No power to temperature controller Power Master switch in OVEN COOL position Door or door switch open No heat LED o...

Page 55: ...open sensor If the condition causing the error is resolved the error will clear Er10 Stack overflow error Microprocessor malfunction Cycle Power Check sensor and connections for a reversed or open se...

Page 56: ...Check spark gap gap should be 1 8 C Check for flame current in flame sense wire 0 000001 Amp Min DC using FC designated terminals 1 Check burner adjustment air gas NOTE If A thru C check out replace i...

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