Blodgett MT2136 Series, Service And Repair Manual

Page 1: ...ttcorp com 50 Lakeside Avenue Box 586 Burlington Vermont 05402 USA Telephone 802 658Ć6600 Fax 802 864Ć0183 PN M9884 A 6 01 1999 G S Blodgett Corporation All rights reserved Duplication of the information in this manual is prohibited without the consent of the Blodgett Service Department ...

Page 2: ...ive System 3 2 Computer Controller 3 3 Sequence of Operation 3 5 MT2136E Domestic with Athena controls M2190 Rev H 3 5 MT2136E General Export with Athena controls M2341 Rev F 3 7 MT2136G Australian Unit with Athena Control M2847 Rev C 3 9 MT2136G CE with Athena Control M3163 Rev C 3 11 MT2136G Domestic with Remote Computer control M3476 Rev b 3 13 MT2136G Domestic with Open Loop Computer Control M...

Page 3: ...rols 4 7 Temperature Calibration 4 9 Belt Speed Calibration 4 10 Motor Control Board Adjustment 4 13 Rerating the Appliance 4 15 Checking the Firing Rate 4 16 5 TROUBLESHOOTING DC Drive System 5 1 Convection System 5 3 Heating System 5 4 Computer Control System 5 6 6 TECHNICAL APPENDIX Intermittent Ignition System 6 1 Principles of Operation 6 1 Service Procedures 6 2 Cooking Computer Temperature ...

Page 4: ...INTRODUCTION CHAPTER 1 ...

Page 5: ... HIGH LEG TO ANY CONVEYOR OVEN Installations within the U S MT2136G ovens require a 15 amp 60HZ 1F 120 208Ć240 VAC 4 wire service consisting of L1 L2 neutral and ground See FIGURE 1 Use 90 C wire and size to National Electric or local codes MT2136E ovens are available in either 1F or 3F opĆ tions Single phase models require a 15 amp 60 HZ 208Ć240 VAC 3 wire service consisting of L1 L2 and ground T...

Page 6: ... service consisting of L1 neutral and ground Connect exhaust fan connector 1 and 2 See FIGURE 2 Use 90 C wire and size according to local codes NOTE If the phase and neutral are switched the control locks out The MT2136E requires a 15 amp 50Hz 3F 230 VAC 5 wire service consisting of L1 L2 L3 neutral and ground See FIGURE 2 Use 90 C wire and size according to local codes 240 É É s Connector 1 2 L3 ...

Page 7: ...re that your meĆ ter will provide the proper supply Installations within the U S 1 Add the total BTU s hr of all the gas appliances 2 Convert BTU s to cubic ft hr using the formula Cu Ft Hr 1000 BTU Hr for natural gas 3 Size the meter accordingly Installations outside the U S 1 Add the total M3 min of all the appliances 2 Size the meter accordingly DOMESTIC AND GENERAL EXPORT Natural Gas Propane G...

Page 8: ...d Loop M7202 Conversion Kit Open Loop to Closed Loop Computerized M3146 Time Display Digital M3147 PickĆUp PVĆ10 For M3146 M0200 Lock Speed Control PotentiomĆ eter M0201 Dial Speed Control PotentiomeĆ ter 21169 Knob Speed Control PotentiomĆ eter M2378 Motor Conveyor Drive Bodine 130V M2500 Brush Set Bodine M2738 Chain Drive M2011 Conveyor Assy Drive Side SB M2012 Conveyor Assy Idle Side SB M2207 C...

Page 9: ...re RTD 500 OHMS M3347 Cable Computer Control 25 Pin 10 Foot M3348 Cable Computer Control 9 Pin 10 Foot M3490 Cable Computer Control 25 Pin 50 Foot M3491 Cable Computer Control 9 Pin 50 Foot M3314 Bracket Computer Wall M5661 Bracket Assy Cable Clamp 19 22672 Relay Control Ice Cube Qty 4 18 M3295 Thermostat High Limit Manual Reset M0152 Contact Emergency Stop Switch M3296 Activator Emergency Stop Sw...

Page 10: ...plete 8 M0415 Flame Sensor 9 M0697 Orifice Pilot Natural 9 M2690 Orifice Pilot LP 10 M3203 Orifice Main Burner Natural MTD 29 10 M1491 Orifice Main Burner LP MTD 45 M2140 Flame Tube Assy 16 M1054 Spark Box 24V 11 M5495 Dual Solenoid Pressure RegulaĆ tor Nat 24V 11 22190 Dual Solenoid Pressure RegulaĆ tor LP 24V M3434 Conversion Kit Natural to LP MTD 45 M3435 Conversion Kit LP to Natural MTD 29 186...

Page 11: ...e M0593 Terminal Block 2 Pole Neutrals w Push On Terminals M3714 Terminal Block 3 Pole Power MT2136E w Allen Head Screws 25 M0708 Contactor Mechanical 16 AMP 3 Pole 120V Coil Motor M2483 Contactor Mercury 60 AMP 3 Pole 120V Coil Heat M2720 Contactor Mercury 100 AMP 2 Pole 120V Coil Heat M7170 Transformer 240V to 115V M2469 Fan Axial 110 CFM 4Ć1 2 Qty 3 or AB Qty 4 M0571 Guard Hardware Fan Qty 3 or...

Page 12: ... 30 M3553 Access Panel Control Box Integral 31 M4580 Access Panel Front w Door M2072 Access Panel Front w o Door M2514 Bolt Front Access Panel Allen Head Decoration M3420 Gasket Assy Front Access PanĆ el M3574 Retainer Gasket Top Bottom w Door M3575 Retainer Gasket LH RH w Door M2731 Retainer Gasket Top Bottom w o Door M2732 Retainer Gasket LH RH w o Door M2801 Hinge Pin Plate Assy 16470 Nameplate...

Page 13: ...tion Ć Vented M6995 Crumb Pan Drive w Remote Top Middle Section Ć Vented M5068 Crumb Pan Drive w Intergal Top Middle Section M7002 Extension Assy Product 6 M6997 Extension Assy Product 12 M7000 False Front w o Door M7001 False Front w Door M6213 Access Panel Combustion Compartment M6035 Latch Combustion Compartment Access Panel M4580 Access Panel Front w Door M6389 Access Panel Front w o Door M273...

Page 14: ... Kit Cooling Fan ExĆ port M3153 Speed Control Board Digital 180VDC M3128 Motor Conveyor Drive 180VDC M3155 Controller Temperature C 50 HZ M2819 Switch Air Pressure Differential in W C Qty 1 Australia M7880 Computer Control Kit Closed Loop SB CE M3237 Burner Assy CE 16 M7334 Pilot Burner Igniter Assy NatĆ ural CE 16 M7333 Pilot Burner Igniter Assy LP CE M2497 Switch Push Button CE M2498 Switch Cont...

Page 15: ...MT2136 1 11 35 30 35 29 39 28 38 33 34 31 37 36 26 27 32 EXTERIOR COMPONENTS FIGURE 3 ...

Page 16: ...INTRODUCTION 1 12 DOMESTIC GAS BURNER COMPONENTS Control Box not Shown 2 1 3 4 5 7 8 9 10 6 15 14 11 12 13 13 13 FIGURE 4 ...

Page 17: ...MT2136 1 13 CE GAS BURNER COMPONENTS Control Box not Shown 16 17 FIGURE 5 ...

Page 18: ...INTRODUCTION 1 14 CONTROL PLATE ASSEMBLY 18 25 16 26 21 19 20 24 23 22 EXCLUSIVE TO CE 40 41 42 43 FIGURE 6 ...

Page 19: ...MT2136 1 15 This page intentionally left blank ...

Page 20: ...ASSEMBLY CHAPTER 2 ...

Page 21: ...AIN 1 Install the drive chain around the drive motor through the opening in the control panel door and then around the sprocket on the conveyor belt support 2 Push the conveyor motor to tighten the drive chain and lock it into position by tightening the hex socket head screws NOTE Twin belt models have a double sprocket chain and motor WIRE CONVEYOR BELT NOTE The conveyor belt has loops on both si...

Page 22: ...NEL EXTENSIONS 1 Install the conveyor tunnel extensions over the conveyor on each end of the oven CONVEYOR BELT TENSIONERS Each tensioner installs between the idle end of the conveyor the side opposite the drive and the oven s body side 1 The belt tensioner contain a spring to adjust the length Compress the spring to shorten the length of the belt tensioner 2 Insert the pin on the end of the tensi...

Page 23: ...MT2136 2 3 This page intentionally left blank ...

Page 24: ...OPERATION CHAPTER 3 ...

Page 25: ... spark ignites the burner Initial start may require longer due to air in the gas line NOTE If the oven fails to ignite after the thirty 30 second purge turn the HEAT SWITCH 5 to OFF and wait 5 minutes before turning back to ON 5 Turn the CONVEYOR SWITCH 7 to ON The conveyor belt starts to travel through the oven This circuit is independent and can be turned on or off without affecting any other op...

Page 26: ...the UP or DOWN ARROW keys 7 to enĆ ter the desired cook temperature 4 Turn the HEAT SWITCH 8 to ON NOTE If the oven fails to ignite after the thirty 30 second purge turn the blower switch OFF and wait 5 minutes before turning back ON 5 Press the ACTUAL TEMPERATURE KEY 3 If the actual temperature matches the setpoint the oven is ready to cook NOTE The display will flash until the actual temperature...

Page 27: ...switch Should you need to stop the belt fans or heat press the emergency switch Do not use the emergency switch as a GENERAL on off switch CONTROL OPERATION To turn the oven on 1 Press and hold the ON OFF key 2 The disĆ play reads OFF when the oven is idle 2 The display flashes WAIT LOW SET TIME 3 The FAN and HEAT status lamps 9 light The fans begin to run The heat rises to the proĆ grammed temper...

Page 28: ...splay will flash WAIT LOW SET TIME until the programmed bake temperature is reached The HEAT lamp 9 will remain lit until the oven reaches the temperature set point 4 The display reads READY and the HEAT lamp 9 goes out 5 The oven is now ready to accept product 6 Press and hold the ON OFF key 2 to turn the oven off The fans continue to run while the oven cools to a safe temperature DISPLAY INFORMA...

Page 29: ...is shut down to keep the convection fans 5 operatĆ ing until the unit reaches 135Ć170 F 57Ć77 C as sensed by the thermocouples 6 NOTE Two thermocouples are located beĆ tween the convection fans in the rear of the oven One thermocouple provides DC millivolts to the Hi Lo limit board The other provides DC milivolts to the temperature controller Check thermoĆ couples with a millivolt meter 2 Turn the...

Page 30: ...itch is located in the slide out control compartment It protects the controls from hi ambient heat 5 The conveyor is driven by an open loop D C control system consisting of a conveyor switch 15 time display 16 10kW potentiometer 17 D C speed control board 18 130 VDC motor 19 and 10 Hall effect pickup 20 AfĆ ter the conveyor switch is turned on the time display illuminates The D C control board pow...

Page 31: ...beĆ tween the convection fans in the rear of the oven One thermocouple provides DC millivolts to the Hi Lo limit board The other provides DC milivolts to the temperature controller Check thermoĆ couples with a millivolt meter 2 Turn the heat switch 7 to ON 115 VAC is supĆ plied to terminal 5 of the hi lo board 2 If the temperature is below 600 F 316 C a switch is made between terminals 5 and 6 all...

Page 32: ...f the switch NOTE The switch is located in the slide out control compartment It protects the controls from hi ambient heat 5 The conveyor is driven by an open loop D C control system consisting of a conveyor switch 15 time display 16 10kW potentiometer 17 D C speed control board 18 180 VDC motor 19 and 10 Hall effect pickup 20 AfĆ ter the conveyor switch is turned on the time display illuminates T...

Page 33: ...s sensed by the thermocouples 6 NOTE Two thermocouples are located beĆ tween the convection fans in the rear of the oven One thermocouple provides DC millivolts to the Hi Lo limit board The other provides DC milivolts to the temperature controller Check thermoĆ couples with a millivolt meter 2 Turn the heat switch 7 to ON 240 VAC is supĆ plied to terminal 5 of the hi lo board 2 If the temperature ...

Page 34: ...e two blowers in the rear convection fan compartment It protects the convecĆ tion fans from hi ambient heat A third cooling fan 18 is located in the control box compartment This fan is activated when another N O SPST thermal switch 20 closes The switch toggles if the temperature passing its face exceeds the rating on the back of the switch NOTE The switch is located in the slide out control compar...

Page 35: ...eep the convection fans 5 operating until the unit reaches 57 77 C 135 170 F as sensed by the thermocouples 6 NOTE Two thermocouples are located beĆ tween the middle convection fans in the rear of the oven One thermocouple provides DC millivolts to the Hi Lo limit board The other provides DC milivolts to the temperature controller Check thermocouples with a millivolt meter 2 Turn the heat switch 7...

Page 36: ...larity 5 When power is applied to the coil of the motor contactor 3 the contacts close sending powĆ er to the two convection fans 5 located in the rear of the oven NOTE Terminals 13 and 14 of the motor contactor act as a hood interlock They are sometimes used as a means of starting the hood 6 There are two cooling fans 21 located in the rear convection fan compartment These fans are activated when...

Page 37: ...flows to the primary side of a 115 24 volt step down transformer 7 and the combustion motor 8 of the flame blower The combustion motor powers up When the combustion motor reaches full speed a centrifugal switch 9 closes sending 24 VAC to the ignition module 10 After the module s self diagnostics are complete the pilot valve 11 opens When a proof of flame is established the main burner valve 12 pow...

Page 38: ... the motor varies from 20 to130 VDC based on the DAC voltage applied to the board or the time programmed into the computer NOTE The DAC receives 20 VDC from the speed control boards The DAC reĆ turns a portion of the voltage between 47 and 4 7 VDC The amount of voltĆ age is dependent on the time proĆ grammed into the computer NOTE This type of system does not sense the weight of the product and wi...

Page 39: ...the high limit switch is closed power flows to the primary side of a 115 24 volt step down transformer 7 and the combustion motor 8 of the flame blower The combustion motor powers up When the combustion motor reaches full speed a centrifugal switch 9 closes sending 24 VAC to the ignition module 10 After the module s self diagnostics are complete the pilot valve 11 opens When a proof of flame is es...

Page 40: ...t 5 The conveyor is driven by an open loop DC control system consisting of a DC speed conĆ trol board 5 a 130 VDC motor 22 and the DAC located in the cooking computer 1 If a time is programmed into the cooking computĆ er a voltage ranging between 47 and 4 7 is apĆ plied to the DC speed control board The outĆ put voltage measured at A1 and A2 of the board to the motor varies from 20 to130 VDC based...

Page 41: ...exceeds the high limit proĆ grammed into the cooking computer NOTE The single pole single throw N C therĆ mal switch is a high limit device located between the two blowers in the rear convection fan compartment This switch opens when the temperature passing its face exceeds the rating on the back of the switch and closes when there is a 10Ć205 drop in temperature across the face of the switch If t...

Page 42: ...applied to the board or the time programmed into the computer NOTE The DAC receives 20 VDC from the speed control board The DAC returns a portion of the voltage between 3 and 3 8 VDC The amount of voltage is dependent on the time programmed into the computer NOTE This type of system does sense the weight of the product and will not slow down if the belt is fully loaded NOTE The control voltage is ...

Page 43: ...hes is located in the junction box in the convection fan compartment The other thermal switch is located in the cooking comĆ puter compartment Two cooling fans 8 are located in the rear of the oven These cooling fans protect the conĆ vection fans from high ambient heat Two addiĆ tional cooling fans 8 are located in the comĆ puter control compartment These cooling fans protect the controls from hig...

Page 44: ...oltage meaĆ sured at terminals A1 and A2 varies from 20 to 130 VDC based on the DAC voltage applied to the board or the time programmed into the computer NOTE The DAC receives 20 VDC from the speed control board The DAC returns a portion of the voltage between 3 and 3 8 VDC The amount of voltage is dependent on the time programmed into the computer NOTE This type of system does sense the weight of...

Page 45: ...the coil of the motor contactor 2 Points 1 2 5 and 6 close powering the convection fans 3 4 3 The convection fan pressure switch 5 closes due to the vacuum that is established in the burner tube chamber by the operation of the convection fans 4 The belt stop relay 6 sends 230 volts to the DC drive board 7 and the manual reset hi limit switch 8 The DC motor 24 starts provided there is a time entere...

Page 46: ... front of the combustion blower motor The information is in the form of resistĆ ance The resistance ascends as temĆ perature increases 10 Two sets of contacts are used as a hood interĆ lock in the motor contactor 2 terminals 13 and 14 At this point there is no power to these terminals they act only as a switch to turn on the hood when the oven is turned on NOTE This is an option that the customer ...

Page 47: ...plied to one side of the relays from a 240Ć120 volt step down transformer 19 3 The belt stop relay 3 sends 115VAC to the DC drive board 8 and one side of a single pole single thermal switch 9 The DC motor 10 starts provided there is a time entered in the cooking computer 1 NOTE The thermal switch is located in the rear of the blower compartment This switch opens when the face of the switch sees 14...

Page 48: ... voltage applied to the board or the time programmed into the computer NOTE The DAC receives 20 VDC from the speed control board The DAC returns a portion of the voltage between 3 and 3 8 VDC The amount of voltage is dependent on the time programmed into the computer NOTE This type of system does sense the weight of the product and will not slow down if the belt is fully loaded 8 There are two coo...

Page 49: ...MT2136 3 25 16 17 18 19 20 21 12 13 13 13 4 7 15 3 2 1 14 8 9 10 6 11 5 5 FIGURE 4 ...

Page 50: ...OPERATION 3 26 16 17 20 19 18 15 3 12 13 13 13 4 14 7 1 2 8 9 10 6 11 5 5 FIGURE 5 ...

Page 51: ...MT2136 3 27 22 23 24 25 26 21 19 18 18 18 4 7 1 3 2 20 5 5 11 12 13 14 15 16 8 17 6 9 10 FIGURE 6 ...

Page 52: ...OPERATION 3 28 25 26 27 29 28 2 24 23 22 21 21 21 3 1 7 20 4 16 17 18 19 14 15 8 10 6 11 12 13 9 5 5 FIGURE 7 ...

Page 53: ...MT2136 3 29 1 17 3 2 4 16 16 16 15 21 5 13 14 14 10 18 19 6 7 8 20 9 12 11 FIGURE 8 ...

Page 54: ...OPERATION 3 30 1 18 16 16 16 16 17 15 22 5 3 2 4 13 10 19 20 6 7 8 21 9 12 11 14 14 FIGURE 9 ...

Page 55: ...MT2136 3 31 1 21 21 21 17 16 22 18 20 19 14 3 2 4 11 6 13 12 15 10 7 8 9 5 FIGURE 10 ...

Page 56: ...OPERATION 3 32 1 8 8 8 8 6 7 16 15 17 18 3 2 4 11 5 9 9 12 13 14 FIGURE 11 ...

Page 57: ...MT2136 3 33 1 6 9 8 19 22 21 7 16 17 2 3 4 18 5 10 14 20 12 11 13 15 25 25 25 24 FIGURE 12 ...

Page 58: ...OPERATION 3 34 1 FIGURE 13 ...

Page 59: ... depending on the food items Air flow adjustments may be necessary to fine tune the oven for your particular product The air plates located at the top of the baking chamber contain holes that can be covered using BlockĆoff Plates The plates can easily be adjusted to regulate the air flow for your particular needs Use the following guidelines to adjust the BlockĆoff Plates 1 Ensure the oven is Off ...

Page 60: ...CALIBRATION AND ADJUSTMENT CHAPTER 4 ...

Page 61: ...If the measured amperage is less than 5 check for proper motor rotation direction TO CHECK LOWĆLIMIT 1 Turn the oven on and let it heat up to approxiĆ mately 200 F 93 C 2 Shut the oven off The blowers should come back on in several seconds 3 When the blowers shut off turn the oven on If computer controlled press the ACT TEMP key to verify that the blowers shut off between 135 F 57 C and 170 F 77 C...

Page 62: ...wer the gas pressure Be sure to reinstall the screw cap should the diaĆ phragm rupture this cap acts as a flow limiter The air shutter disc on the burner blower motor loĆ cated inside the control box at the top of the asĆ sembly is factory adjusted to provide the most effiĆ cient blue flame possible at sea level Visually examine the flame to verify it s quality Should it need adjustment increase o...

Page 63: ...lens cover If a 5 pulse pickup is used verify that the multiplier potentiometer is set to the x10 position refer to FIGURE 4 for the potentiometer location Cooking Time INCREASE DECREASE X1 X10 Belt speed DIP switch located behind cooking time digital display Multiplier potentiometer located behind cooking time digital display For 5 pulse pickups set to x10 FIGURE 4 Set The Belt Speed DIP Switches...

Page 64: ... counterĆclockwise rotation raises the reading and decreases the temperature Check the oven set point Adjustment of the potentiometer may affect this reading Bring the oven up to 525 F 274 C Verify the caliĆ bration 4 Set Point Adjustment Ć Adjust the Coarse ManĆ ual so the controller calls for heat at 522 F 272 C and shutĆoffs at 525 F 274 C A clockwise rotation raises the temperature counterĆclo...

Page 65: ...F Ć70 C to 70 C 1 Use the arrow keys to select the desired disĆ play offset 2 Press the actual temperature key to enter the selected offset value The display will toggle between and a numerical value Setting the Deviation Band Alarm The deviation band alarm causes the display to flash when the actual temperature varies in either direction from the setpoint The deviation band alarm is adjustable to...

Page 66: ...Remove the wires from the common and N O terminals Touch the wires together to energize the heat circuit This enables the oven to heat above the highest temperature allowed by the controller 2 When the display reads 600 F 316 C the burner blower motor should shut off If the temĆ perature rises above 600 F 316 C adjust the hiĆlimit pot FIGURE 7 so the burner shuts off at 600 F 316 C A clockwise rot...

Page 67: ... entries in the chart below If the data does not match the chart it should be changed accordingly When the correct data is disĆ played press the PROG ENTER key the display will cycle on to the next screen If a step is missed press the CLEAR button to backup DISPLAY ACTION TAKEN DISPLAY ACTION TAKEN F CMODE Press PROG ENTER T F C Press again or hit any number and it will change PROG ENTER POS OFFSE...

Page 68: ...pressing PROG ENTER the last time the disĆ play will show EXIT then beep and return to the ACCESS mode Pressing and holding the ON OFF key will turn the oven on A new time and temĆ perature must be entered upon exiting the ACĆ CESS mode since the oven will automatically default to 0 The oven will not fire until both time and temperature are entered Firmware Model Version Display Password CLEAR 1 2...

Page 69: ...desired setpoint 3 Press the PROG ENTER key To program the temperature offset To change the temperature calibration an offset positive or negative must be programmed 1 Press PROG ENTER followed by ACT_TEMP The display flashes either POS OFFSET or NEG OFFSET NOTE POS OFFSET is displayed if a value has been programmed in for a positive offĆ set NEG OFFSET is displayed if a valĆ ue has been programme...

Page 70: ...he time from entrance to exit Enter the actual measured time 4 ENTER TEST TIME If the actual measured time is not within 5 seconds of the test time reĆ peat the belt verification test to obtain better accuracy If the actual measured time is acĆ ceptable press the CLEAR key to continue the belt speed calibration 5 MAX MIN CALC TIME The control sets the fastest and slowest cook time the user can pro...

Page 71: ...ration procedure minimum belt speed The motor control is automatically set to its minimum output The belt will travel very slowly during this part of the calibration procedure To minimize the time spent on STEP 2 measure off 10 on the conveyor support Place an object on the belt and note the travel time for the 10 measured distance A The display reads STEP 2 TIME Enter the measured travel time for...

Page 72: ...Press the PROG ENĆ TER key 3 The display reads STEP 2 The controller is in Step 2 of the calibration procedure minimum belt speed The motor control is automatically set to its minimum output The belt will travel very slowly during this part of the calibration procedure To minimize the time spent on STEP 2 measure off 10 on the conveyor support Place an object on the belt and note the travel time f...

Page 73: ...s within 3VDC of the specified voltage NOTE For computerized closed loop sysĆ tems this adjustment must be made quickly Low Speed Motor Adjustment For closed loop systems the computer automatiĆ cally proceeds to low speed For open loop sysĆ tems continue Belt Speed Calibration through STEP 3 see page 4 11 or 4 12 1 With the motor connected make no open cirĆ cuit voltage readings measure the voltag...

Page 74: ...tment Test Points Maximum Speed Minimum Speed Acceleration Adjustment ACC MAX MIN TORQ Socket J1 Line Fuse FL REG L N A1 A2 TB1 Speed Pot Yellow or Violet pin 12 Blue pin 8 Ć Torque current limiting adjustment DO NOT ADJUST FA DIP Switch on early models only Switches 2 4 5 6 7 NOTE Colors may vary between early ovens Orange or Gray pin 10 Violet Gray Blue ON TP2 TP1 Line Hot VAC Armature Fuse PM M...

Page 75: ... your local gas supĆ plier for values Use the following formulas to calculate the correct orifice 1 Firing rate of burners ąBTU per burner 2 BTU per burner Heating value of Gas ąCuFt hr 3 CuFt Hr Specific Gravity Multiplier ąEquiv CuFt hr 4 Use TABLE FĆ1 from the National Fuel Gas Code Handbook to determine the proper oriĆ fice size at sea level NOTE The sea level orifice size is needed to determi...

Page 76: ... Natural Gas 1000 x 120 120 000 BTU Propane 2550 x 120 306 000 BTU Butane 3000 x 120 360 000 BTU NOTE You may also use TABLE XII from the National Fuel Gas Code Handbook to aid in determining the firing rate of the appliance This table eliminates the use of the formulas above Locate the time observed in STEP 2 Move across the table to either the 1 2 cu ft or the 2 cu ft column to find the gas inpu...

Page 77: ...MT2136 4 17 This page intentionally left blank ...

Page 78: ...TROUBLESHOOTING CHAPTER 5 ...

Page 79: ...troller cord connection Time not programmed into computer Emergency stop switch on OFF Control circuit breaker tripped Belt hooked on something in oven 5 amp line fuse blown 200 milliamp armature fuse blown Hall Effect Pickup not connected Closed loop systems only Motor brushes worn out Defective conveyor drive motor Defective conveyor drive motor controller Wire from pickup open or misplaced DAC ...

Page 80: ...le component of the computer There should be approximately 20 VDC between the red and green wires on the 3 pin connection of the DC drive board DAC voltage is present but not regulated beĆ tween 4 7 and 47 VDC when different times are programmed into the cooking computer MeaĆ sure the voltage between the green and blue wires of the 3 pin connection See Calibration and Adjustments Replace the drive...

Page 81: ...r switch Replace motor contactor Symptom 2 Blower motor s do not shut off Faulty motor contactor Faulty thermocouple on Hi Lo board Faulty Hi Lo board Hi Lo board is not adjusted properly Replace contactor Refer to the chart on page 6 5 of the Technical Appendix If the readings do not match replace the thermocouple Determine if 115 VAC is coming out of 7 with the adjustable potentiometer turned co...

Page 82: ... low Turn the oven on Determine if the circuit breaker is tripped Replace the fuse If the setpoint is not above the actual reset acĆ cordingly Reference Technical Appendix page 6 1 through 6 3 Check convection blower for proper operation Verify voltage to motor If voltage is present reĆ place the motor or start capacitor Verify that the temperature in the front panel is lower than 140 F 60 C Verif...

Page 83: ...t to ON Reset breaker Check transformer for primary and secondary voltage Check main control and burner valve relays to see if closed Check relay in combustion burner box If bad reĆ place relay Set to desired temperature Open valve Reference Technical Appendix page 6 1 through 6 3 Check convection blower for proper operation Verify voltage to motor If voltage is present reĆ place the motor or star...

Page 84: ...e controller has been programmed the computer may need to be replaced Symptom 3 Oven will not reach desired temperature Gas pressure to oven is too low Top air plates missing or not adjustable Faulty RTD probe Blower motor s running backward Controller out of calibration Excessive food debris accumulation blocking the airflow Contact local gas representatives Install adjust air plates Use the char...

Page 85: ...e 140 F 60 C check the cooling fan operation Use the chart in the Technical Appendix page 6 4 to determine if probe is bad Replace if necĆ essary The inside of the oven should be cleaned to reĆ move any materials that could have dropped off the conveyor belt and possibly blocked some of the air flow holes This would include the removal of the conveyor belt conveyor belt supports and the nozzles Th...

Page 86: ...TECHNICAL APPENDIX CHAPTER 6 ...

Page 87: ...trol through the flame sensor cable to the flame sensor As the current is conducted through the flame to the pilot hood it is rectified from AC to DC because of the difference in surface area The pilot hood is grounded back to the control thereby completing the circuit Flame Sensing Circuit Current For the ignition control to function properly a miniĆ mum amount of current must flow through the fl...

Page 88: ...er supply to the ignition conĆ trol 2 Disconnect the flame sensor cable from termiĆ nal 4 on Johnson units or terminal 15 on Landis Gyr units 3 Set the selector switch on the meter to microĆ amp scale Connect the positive red lead to terminal 4 and the negative black lead to the sensor cable 4 Disconnect the main valve lead from terminal 3 This will prevent the main burner from ignitĆ ing A proper...

Page 89: ... secure 6 Restore the power and the gas supply to the appliance 7 IMPORTANT Using a microammeter check the signal passing through the sensing probe 8 If the microamp signal is marginal trim the flame sensing probe in increments of 1 8 Be sure that there is still proper flame impingeĆ ment on the flame sensing probe Flame must surround sensing probe tip for approximately 1 2 9 Observe at least thre...

Page 90: ... 290 774 11 450 938 118 615 1102 447 135 610 86 295 779 31 455 943 17 620 1107 35 140 616 2 300 784 5 460 948 216 625 1112 249 145 621 52 305 789 68 465 953 259 630 1117 1 150 626 85 310 794 87 470 958 296 635 1122 155 632 17 315 800 04 475 963 33 640 1126 9 160 637 48 320 805 21 480 968 359 645 1131 8 165 642 8 325 810 38 485 973 383 650 1136 7 170 648 1 330 815 54 490 978 403 655 1141 6 175 653 ...

Page 91: ... 641 7 794 300 7 947 8 100 310 8 253 8 407 320 8 560 8 714 330 8 867 9 021 340 9 175 9 329 350 9 483 9 636 F Reading 5 F 360 9 790 9 944 370 10 098 10 252 380 10 407 10 561 390 10 715 10 869 400 11 023 11 177 410 11 332 11 486 420 11 640 11 794 430 11 949 12 103 440 12 257 12 411 450 12 566 12 720 460 12 874 12 029 470 13 183 13 337 480 13 491 13 645 490 13 800 13 954 500 14 108 14 262 510 14 416 ...

Page 92: ...eters meters 3 281 feet pounds 4536 kg inches W C 249082 kPa 2 49082 mbar kPa 4 01885 inches W C 10 mbar mbar 0 401474 inches W C kW 3 6 Mj hr kcal m3 1122952 BTU ft3 Kwh m3 96 65 BTU ft3 TABLE 4 PRESSURE CONVERSIONS FACTORS Multiply By To Get in H2O 0 0361 P S I 25 41 mm H2O 1 868 mm Hg 0025 kg cm2 0025 bar 2 489 mbar 248 9 Pa 2489 kPa P S I 27 71 in H2O 2 036 in Hg 703 1 mm H2O 51 75 mm Hg 0703 ...

Page 93: ... 37 2737 2 737 12 4331 8818 304 8 22 412 0304 0299 29 86 2986 2 986 13 4692 9553 330 2 24 280 0330 0324 32 35 3235 3 235 14 5053 1 029 355 6 26 148 0355 0348 34 84 3484 3 484 15 5414 1 102 381 0 28 016 0381 0373 37 33 3733 3 733 16 5774 1 176 406 4 29 879 0406 0398 39 81 3981 3 981 17 6136 1 249 431 8 31 752 0431 0423 42 31 4231 4 231 18 6496 1 322 457 2 33 616 0457 0448 44 79 4479 4 479 19 6857 1...

Page 94: ...8 40 1 444 2 940 1016 74 72 1015 0996 99 56 9956 9 956 41 1 480 3 013 1042 76 59 1040 1020 102 0 10204 10 20 42 1 516 3 086 1067 78 45 1066 1045 104 5 10452 10 45 43 1 552 3 160 1092 80 31 1091 1070 107 0 10701 10 70 44 1 588 3 233 1118 82 18 1116 1095 109 5 10949 10 95 45 1 624 3 306 1143 84 04 1142 1120 112 0 11197 11 20 46 1 660 3 378 1168 85 90 1167 1144 114 5 11445 11 44 47 1 696 3 453 1194 8...