Vulcan-Hart 126172 Service Manual Download Page 68

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ELECTRIC COMBI OVENS - TROUBLESHOOTING

SYMPTOM

POSSIBLE CAUSES

Form 24659 (September 1999)

Printed in USA

Inner door glass breaks.

Glass installed incorrectly with conductive side toward
oven cavity. See “OVEN DOOR” under “REMOVAL AND
REPLACEMENT OF PARTS”.

Steam generator drains continually.

Relay board malfunction (K3, K5).

Oven control board malfunction.

Cavity fan motor squeaks.

Motor seal - grease is dry or dirty.

Motor shaft rubbing against the opening in the rear of the
cavity.

NOTE: This may only occur when the cavity is at a high
temperature. If this is true, then remove the motor and
inspect the shaft for scratches..

Motor malfunction.

Cavity lamp not working.

Lamp inoperative.

Power wires to lamp loose or not connected to
transformer (1T).

Transformer (1T) malfunction.

Relay board malfunction (K3 relay).

Oven control board malfunction.

Steam leaks around door.

Door not sealing or locking properly. See “OVEN DOOR
ADJUSTMENT” under “SERVICE PROCEDURES AND
ADJUSTMENTS”.

Summary of Contents for 126172

Page 1: ...ve 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 ...

Page 2: ...nt Damper Assembly 15 Water Level Sensors and Water Equalization Tube 16 Steam Generator Tank 17 Oven Door 18 Door Lamp 19 Oven Door Hinges 19 Door Magnetic Reed Switch 20 Door Seal 20 Door Locking Mechanism 20 Oven Cavity Seal 21 Power Supply Board and Transformer 22 Contactors 22 Oven Cavity Drain 23 SERVICE PROCEDURES AND ADJUSTMENTS 24 Configuration Mode Programable Control 24 Diagnostic Test ...

Page 3: ... Heating Mode and Cavity Fan Speeds 42 Heating Regulation 42 Steam Pre Heat 43 Steam Regulation 43 Water Injection Humidifier 44 Cool Down Mode Manual Controls 44 Programable Oven Control 45 Manual Oven Controls 49 Wiring Diagrams 54 6 Level 54 10 Level 56 20 Level 58 Electric Heater Circuits 60 TROUBLESHOOTING 63 VULCAN 1999 ...

Page 4: ...6 level only and in three sizes 6H 10H F and 20H F OPERATION Refer to the Installation Operation Manual for specific operating instructions CLEANING Refer to the Installation Operation Manual for specific cleaning instructions STACKING KIT INSTRUCTIONS When servicing stacked ovens and disassembly is required refer to the Stacking Kit Instructions for specific assembly procedures SPECIFICATIONS Wat...

Page 5: ...onvection heat mode 3 Complied in accordance with National Electric Code ANSI NFPA 70 latest edition MODEL INDIVIDUAL AMPERAGE 3 PHASE 60HZ 1 CONVECTION HEAT 2 STEAM GENERATOR HEAT 3 ELEMENTS 208V 240V 480V ELEMENTS 208V 240V 480V KW NO KW NO VCE6H 9 1 25 22 11 8 1 22 19 10 VCE10H 9 2 50 43 22 8 2 45 39 19 VCE10F 9 2 50 43 22 8 2 45 39 19 VCE20H 6 4 67 58 29 8 3 67 58 29 VCE20F 9 4 100 87 43 8 4 8...

Page 6: ...ELECTRIC COMBI OVENS GENERAL Page 6 of 68 PROGRAMMABLE STANDARD MANUAL DELUXE MANUAL OVEN CONTROLS ...

Page 7: ... water level Do not use fully demineralized or de ionized water since it is non conductive and the water level can not be detected The use of strainers or filters will not remove minerals from the water Water supplies vary from state to state and from locations within a state Therefore Vulcan recommends that a local water treatment specialist be consulted before the installation of any steam gener...

Page 8: ...el pins 7 After lower dowel pins have been cleared remove assembly from top pins and remove from oven 8 Reverse procedure to install NOTE Be sure the bottom of the exhaust assembly is seated on the dowel pins and fan direction arrow is pointing to left facing oven COVERS AND PANELS WARNING DISCONNECT THE ELECTRICAL POWER TO THE MACHINE AT THE MAIN CIRCUIT BOX PLACE A TAG ON THE CIRCUIT BOX INDICAT...

Page 9: ... Reverse procedure to install OVEN TEMPERATURE PROBE 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 rack guide filter and exhaust assembly as outlined under RACK GUIDE FILTER EXHAUST ASSEMBLY 2 Remove both side panels as outlined under COVERS AND PANELS 3 Remove the retaining nut fr...

Page 10: ...e grounding kit must be used anytime the control board is handled 1 Remove the right side panel as outlined under COVERS AND PANELS 2 Disconnect the ribbon cable connectors and ground leads from the oven control board 3 Remove the cover from the oven control by removing the mounting nuts at the top and bottom 4 Remove the hex nuts securing the CPU board to the display keypad board 5 Pull outwards ...

Page 11: ... PANELS 2 Disconnect the ribbon cable thermocouple connector ground leads and door switch connector from the oven control board 3 Remove the cover from the oven control board by removing the mounting nuts at the top and bottom 4 Remove the oven control board from the control panel by removing the mounting nuts 5 Reverse procedure to install RELAY BOARD WARNING DISCONNECT THE ELECTRICAL POWER TO TH...

Page 12: ...SEMBLY 2 Loosen bolt one turn that secures the blower and install puller 3 Tighten the puller then tap the puller with a hammer to loosen the blower from the motor shaft 4 Remove the puller bolt washer and blower from the motor shaft NOTE If only the blower is being removed reverse the procedure at this point to install 5 Remove the rear panel as outlined under COVERS AND PANELS 6 Disconnect the l...

Page 13: ...e seal from the recess in the rear oven wall NOTE You may have to drive the seal out from the back of the oven 4 Fill replacement seal cover with white silicone grease 5 Assemble the motor seal with the convex part of the spring toward the motor 6 Apply red high temperature RTV to the outer edge of the seal to help hold it in the recess and install the seal with the seal cover toward the front of ...

Page 14: ...stall THERMAL FUSE S 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 2 Disconnect the thermal fuse s lead wire connections 3 Remove the thermal fuse and protective sleeve from the heater thermowell 4 Reverse procedure to install NO...

Page 15: ...connected to the drain pump 5 Remove the bolts from the mounting bracket that secure the pump 6 Reverse procedure to install VENT DAMPER ASSEMBLY 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 Vent Motor 1 Remove the right side panel as outlined under COVERS AND PANELS 2 Disconnect the lead wire...

Page 16: ...the shutters and sealing washer 9 Install new sealing washer and re assemble Shaft Extension 1 Remove the left right and rear panels as outlined under COVERS AND PANELS 2 Open the oven door and remove the rack guide filter and exhaust assembly as outlined under RACK GUIDE FILTER EXHAUST ASSEMBLY 3 Remove the screw and nut behind the motor assembly that connects motor to shaft extension rod 4 Rotat...

Page 17: ...y loosen or remove drain pump mounting nuts to remove tube A Remove heating elements from steam generator tank and place to the side NOTE Unless replacing the heating element s it not necessary to remove the heating element lead wires B On 6 and 10 levels remove clamp from the steam exhaust hose at the top of steam generator and disconnect hose On 20 levels remove the nuts securing the steam exhau...

Page 18: ...ge near the door latch and unsnap the glass from the snap catches in the oven door 4 Open the inner door glass and remove the c ring clamps from the rear snap catches unsnap at the rear then lift off CAUTION When replacing the inner door glass it must be installed with the conductive side toward the front of the oven Use an ohmmeter to verify the conductive side Set the meter to read ohms and touc...

Page 19: ...he life will be reduced Ensure lamp is free from oil and dirt before replacing 4 Pull up on light bulb to remove it from socket 5 Reverse procedure to install OVEN DOOR HINGES 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 and disassemble the door as outlined under OVEN DOOR 2 Remove th...

Page 20: ...ration DOOR SEAL 1 Turn the oven off 2 Open the oven door 3 Remove seal from the edge of the inside glass 4 Clean the edge of the glass remove the old adhesive 5 Apply red silicone to the replacement seal and install the seal to the glass edge The vent holes must be installed to the outside to allow the seal to contract when the door is closed 6 Adjust door closure if necessary as outlined under O...

Page 21: ...ing mechanism The springs locking arm and bushings can be removed 3 Remove the two bolts from the locking mechanism 4 The springs locking arm and bushings can be removed 5 Reverse procedure to install OVEN CAVITY SEAL 1 Open the door 2 Pull the seal from the groove around the oven cavity 3 Push the arrow head tip of the gasket into the groove Install the four corners first 4 Start at the corners a...

Page 22: ...nstall NOTE Ensure transformer tap wire is in the position that corresponds to the machine data plate voltage Refer to the power supply board and transformer 1T component on the wiring diagram for proper connection of the individual lead wires CONTACTORS 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 SER...

Page 23: ...or 2 Lift up the oven cavity drain grate to remove 3 Unscrew t bar nut to release drain at the front 4 Remove rear panel as outlined under COVERS AND PANELS 5 Disconnect the drain pump discharge hose from the drain vent pipe 6 Remove the drain vent pipe from the drain 7 Disconnect the drain cool down water hose from the drain nipple extension 8 Unscrew the drain line piping from the bottom of the ...

Page 24: ...mber of clean cycles completed deliming of steam generator is displayed in the temperature display The number cannot be changed or modified Press the START STOP key to advance to the next step 4 The EPROM revision level is displayed in the time display and Conf is displayed in the temperature display To verify the EPROM is at the current revision level refer to the Technical Service Bulletins Pres...

Page 25: ...e is correct press the START STOP key to advance to the next step CONVECTION FAN MOTOR TYPE CONVECTION FAN MOTOR VALUE POSITION 1 MINIMUM POSITION 2 MAXIMUM 1 motor Leroy Somer Hanning 8 55 1 motor Brook Crompton 8 60 2 motors Leroy Somer Hanning 46 120 2 motors Brook Crompton 30 90 1 motor Leroy Somer Hanning and 1 motor Brook Crompton 38 105 NOTE Ovens are shipped from the factory with this moto...

Page 26: ...ayed in the temperature display With each successful key press the number of the key is displayed in the time display Each key is numbered starting with number 01 ON in the upper left corner of the control and ends at 21 humidifier on the lower right corner See table below Verify that all keypad buttons are functioning properly KEY NO KEY NO ON 01 TEMP 12 OFF 02 TEMP DOWN 13 HOT AIR 03 TEMP UP 14 ...

Page 27: ...erature setting is the boiling point adjustment for elevation and must be set to achieve optimum results Rotate the adjustment knob counterclockwise to decrease and clockwise to increase Set the temperature according to the table below Press the TIME key to advance to the next step NOTE The steam temperature setting will also be the initial cavity set point temperature and the maximum cavity tempe...

Page 28: ...d test is displayed in the temperature display and 10 start button keypad no is displayed in the time display The KEYPAD test consists of rotating the selector switch clockwise through each position pressing each button on the keypad and rotating the adjustment knob clockwise then counterclockwise to check the functionality of each With each successful selection the corresponding number is display...

Page 29: ...ating elements on 10 20 levels 11 K3 K9 contactor KM6 convection heating elements 5 t1 is displayed in the time display and the actual cavity temperature is displayed in the temperature display Verify the probes are sensing temperature correctly Rotate the adjustment knob and select the probe temperature to display T1 cavity probe top on 20 levels T2 bottom cavity probe 20 levels only T3 cooking p...

Page 30: ...T AMPS PER ELEMENT LEAD 3 PH OHMS PER ELEMENT VCE6H VCE10H VCE20F VCE20H 208 8 13 16 240 8 11 22 480 8 10 29 NOTE Values in the table are nominal Tolerance is 5 10 OVEN DOOR ADJUSTMENT NOTE Follow the steps in the order outlined below for proper door adjustment 1 Turn the oven off 2 Check the level of the oven from left to right and front to back in the exact location where the oven is to be posit...

Page 31: ... 9 9 Push the door closed and observe the locking arm It must not contact the bottom edge of the slot that the locking arm travels in while the door is closing 10 With the door in the closed position the roller should be cradled in the locking arm hook 11 Replace the control panel 12 Close the door handle The handle is centered in the cut out of the control panel so the magnet in the handle will o...

Page 32: ...y B To adjust the buzzer frequency follow the procedure as outlined in step 6 under PROGRAMABLE CONTROL CONFIGURATION MODE 3 After the buzzer frequency is set to the desired level press the START STOP key to cycle through the configuration parameters again until reaching the step for setting the buzzer frequency 4 To adjust the buzzer volume turn the buzzer volume adjustment screw until the desire...

Page 33: ...g mode Program number 00 is displayed in the program display Press the down key once to select the clean cycle program or if at program 98 press the up key once to select the clean cycle program Press and hold for automatic scrolling CC is displayed in the program number display and dSCL is displayed in the temperature display Press the START STOP key to start the clean cycle and the start stop LE...

Page 34: ...enerator heating elements and cavity fans turn on 2 As the vinegar level lowers the steam generator will then fill with water as required NOTE If the cavity temperature is above the steam temperature set point automatic cooling will occur See WATER INJECTION HUMIDIFIER under SEQUENCE OF OPERATION D The timer starts counting down and the oven will steam for 30 minutes 5 At the end of 30 minutes A H...

Page 35: ... of possible causes C If code numbers appear in the time and temperature display or the control operation is erratic the battery backup may be malfunctioning 1 Press the keypad ON button If dashes are displayed in the time display and 888c is displayed in the temperature display then battery module voltage may be low WARNING DISCONNECT THE ELECTRICAL POWER TO THE MACHINE AT THE MAIN CIRCUIT BOX PL...

Page 36: ...p the SRAM pins and insert them into the battery module Ensure that all SRAM pins are inserted properly Install the SRAM and battery module assembly onto the CPU board with the notches pointing up Carefully line up the battery module pins and insert them into the socket on the CPU board Ensure that all pins are inserted properly For the one piece SRAM and battery module combination position the mo...

Page 37: ...Fuse FLQ5 Protects L1 power from terminal block and power supply board 1T transformer primary in series with F2 Fuse 1LT Oven Light Illuminates oven cavity 1MTR Cavity Vent Motor Opens and closes oven cavity exhaust port 2MTR Drain Pump Motor Empties water from steam generator 3MTR Cooling Fan Exhausts hot air from right side control compartment to cool components 4MTR Door Motor Pulls door into a...

Page 38: ... Fuse Removes power from KM1 KM2 KM3 KM5 KM6 KM7 20 level full only if steam generator temperature rises above 243 F 1TB Terminal Block Incoming voltage supply connection 1T Power Supply Board Transformer Supplies 12VAC for cavity light 24VAC to relay board and oven control board 230VAC or 90VAC to cavity fan motor s at full or half speed and 230VAC to all other electrical controls except heaters ...

Page 39: ...ent cooling fan s and supplies power to one side of K4 K5 and K6 K7 K8 K9 and K10 through the thermal fuses and high limit thermostats K4 Water Injection Relay Controls power to water injection solenoid valve humidifier and door light when K3 is ON K5 Water Fill Relay Controls power to water fill solenoid valve when K3 is ON and drain pump motor when K3 is OFF K6 Half Power Full Speed Relay Contro...

Page 40: ...ELECTRIC COMBI OVEN ELECTRICAL OPERATION Page 40 of 68 COMPONENT LOCATION ...

Page 41: ...ELECTRIC COMBI OVEN ELECTRICAL OPERATION Page 41 of 68 ...

Page 42: ...e reaches 18 F below set point temperature If the cavity temperature is rising at 3 6 F per second or greater the heating elements will turn off If the cavity temperature does not reach set point or drops more than 18 F below set point the heating elements turn back on at full power until reaching the actual cavity set point temperature then turn off When the cavity temperature drops 0 9 F below s...

Page 43: ... oven control press the Start Stop key to begin steam generator heating The steam generator heating elements turn on always at full power until the actual set point temperature is reached then turn off If the steam mode is selected after convection or combi mode heating the steam generator pre heat is complete and the oven is ready for steam mode cooking At this time if the cavity temperature is l...

Page 44: ...1 Display shows then 11 11 11 indicating the oven is in cool down mode The default temperature is 158 F and can be adjusted if desired a If the oven cavity temperature is above 302 F water will be injected for one second every three seconds until the cavity temperature reaches 302 F b After the oven cavity temperature reaches 302 F water is injected continuously until the cavity temperature is wit...

Page 45: ... displayed B Time displays h min C Oven cavity lamp energized D Cooling fan s energized E Cavity vent motor energized 1 Cavity vent closes NOTE When the oven is turned on the default condition of the cavity vent is closed Pressing the Hot Air key selects the Hot Air mode and the Hot Air Vent closed LED is on Press the Hot Air key a second time to open the vent The Hot air mode is still selected bu...

Page 46: ...he temperature display then reverts to the actual cavity temperature C Steam generator fill solenoid is energized until proper water level is reached then turns off See WATER LEVEL SENSORS under COMPONENT FUNCTION D First LED for the cooking program phase flashes 3 Press the temp key to set the operating temperature The default temperature displayed 195 to 212 F is pre selected in the configuratio...

Page 47: ...gree symbol shows in the temperature display convection and or steam generator heating elements are energized 1 Drain cool down solenoid energized NOTE Whenever steam generator heating elements are on the drain cool down solenoid is energized D Cavity fan motor s energized 5 Oven control monitors cavity temperature and cycles the convection heating elements as necessary to maintain set point tempe...

Page 48: ...e is retained in memory and is displayed when the time key is pressed A Start Stop LED on 4 Internal product temperature reaches probe set point temperature A Buzzer sounds for approximately 10 seconds on and 45 seconds off The buzzer continues to cycle at these times until the Start Stop key is pressed B Probe temperature flashes in the time display C Convection and or steam generator heating ele...

Page 49: ... Down 1 The control can be in any heating mode and the door in the open or closed position 2 Press the off key NOTE There is a four second time delay after pressing the off key to cancel the shut down sequence and resume normal operation A Displays and LED s turn off B All power removed from the heating elements and cavity fan s C Vent motor energized and operates till vent opens D Door unlocks an...

Page 50: ...ode convection combi or steam for the continuation of the sequence Convection Mode 1 Conditions exist as described in POWERING CONTROL 2 With the selector knob rotated to HEAT the cooking cycle begins A Time LED is on and is displayed in the time display B Cavity set point temperature the last temperature that was set is displayed in the temperature display C Convection heating elements energized ...

Page 51: ...CE OF OPERATION A Rotate the adjustment knob clockwise or counterclockwise to adjust the setting temperature symbol stops flashing 1 If a pause of 5 seconds is made during or at the end of the adjustment the temperature symbol will begin to flash When the temperature symbol stops flashing the temperature can no longer be adjusted and the cavity set point temperature is displayed NOTE To display th...

Page 52: ... LED and dashes flash in the time display 2 Rotate the adjustment knob clockwise or counterclockwise to the desired cooking time Time display will be continuous but the time LED will continue to flash A Once the time is set it will flash in the time display for 5 seconds then display the selected time 3 Press the Start key to begin the timed cooking cycle A Start LED on B Timer counts down NOTE As...

Page 53: ...ture flashes in the time display C Probe method remains selected with probe Led on D Probe temperature remains as entered and is displayed in the time display Powering Down 1 The control can be in any heating mode and the door in the open or closed position 2 Rotate the selector knob to off NOTE There is a 5 second time delay after selecting the off position to cancel the shut down sequence and re...

Page 54: ...ELECTRIC COMBI OVEN ELECTRICAL OPERATION Page 54 of 68 WIRING DIAGRAMS 6 Level ...

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Page 60: ...ELECTRIC COMBI OVEN ELECTRICAL OPERATION Page 60 of 68 ELECTRIC HEATER CIRCUITS ...

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Page 63: ... condition can cause water errors prevent the steam generator from filling and cause dry firing of the heating elements Subsequently the steam generators thermal fuse s would open to protect the oven See CLEAN CYCLE MODE STEAM GENERATOR DELIMING under SERVICE PROCEDURES AND ADJUSTMENTS SYMPTOM POSSIBLE CAUSES Water error light on buzzer sounds for one minute and steam generator light comes on in a...

Page 64: ...ol malfunction Oven inoperative and displays are blank 1 Incoming voltage to machine not present or incorrect 2 Line fuses F8 and or F9 open 3 Voltage tap wire on power supply board not connected or connected to wrong voltage for the machine 4 Fuse F1 and or F2 on the power supply board open 5 Ribbon cable connector to relay board and CPU board is not inserted properly NOTE Connector should snap i...

Page 65: ...econds then error code will display 2 Low or no voltage on battery backup to maintain controls setup and program information in SRAM See BATTERY BACKUP PROGRAMMABLE CONTROL under SERVICE PROCEDURES AND ADJUSTMENTS 3 Incorrect temperature probe in use Ensure the temperature probe is not a thermistor type by checking its resistance If resistance measures approximately 110 ohms at 70 80 F then do not...

Page 66: ...not use Temperature display flashes current cavity temperature but oven will not heat or produce steam 1 Door not completely shut or handle not in the closed position 2 Door reed switch malfunction 3 Oven control board malfunction Cavity cooking temperature is lower than actual temperature displayed 1 Cavity temperature probe s thermocouple shorted 2 Incorrect temperature probe in use A Cavity the...

Page 67: ...ntrol s setup and program information in the event of a power loss See BATTERY BACKUP PROGRAMABLE CONTROL under SERVICE PROCEDURES AND ADJUSTMENTS Water in component area 1 Cavity drain gasket not sealing properly 2 Heating element s o ring not sealing properly Water in bottom of cavity 1 Water too soft for water level sensors to conduct electricity 2 Water level sensor leads loose or disconnected...

Page 68: ...al grease is dry or dirty 2 Motor shaft rubbing against the opening in the rear of the cavity NOTE This may only occur when the cavity is at a high temperature If this is true then remove the motor and inspect the shaft for scratches 3 Motor malfunction Cavity lamp not working 1 Lamp inoperative 2 Power wires to lamp loose or not connected to transformer 1T 3 Transformer 1T malfunction 4 Relay boa...

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