Pratica Chef Express Service Manual
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Pratica Chef Express Service Manual

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Service Manual
For the Chef Express Oven
Pratica Products, Inc - USA
675 Town Square Boulevard, Suite 200
© 2018 Pratica Products, Inc - USA
Garland, TX 75040
December 2018

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  • Page 1 Service Manual For the Chef Express Oven Pratica Products, Inc - USA 675 Town Square Boulevard, Suite 200 © 2018 Pratica Products, Inc - USA Garland, TX 75040 December 2018...
  • Page 2 INDEX SAFETY INSTRUCTIONS ................... 1 ........................ 2 MPORTANT AFETY NSTRUCTIONS ......................... 3 ROUNDING NSTRUCTIONS ........................3 OWER EPLACEMENT ..........................3 EDUCTION RECAUTIONS BSERVED EFORE URING ERVICING VOID OSSIBLE XPOSURE XCESSIVE ..........................4 ICROWAVE NERGY SPECIFICATIONS & INSTALLATION ................5 ............................... 6 HEET ............................
  • Page 3 ....................... 44 HERMOCOUPLE EADINGS ..........................44 NFORMATION CREEN ....................45 EMPERATURE EASUREMENT ANGUAGE .............................. 45 ELECTION ....................... 46 REQUENCY NVERTER AULT ........................... 47 AGNETRON ......................48 ONTROL OARD OUNT ............................48 EYPAD MICROWAVE SYSTEM ................... 49 ......................... 50 ICROWAVE YSTEM ............................
  • Page 4 ....................... 91 ESTING ONTROL YSTEM USES FILTERING SYSTEM ....................93 .............................. 94 ILTER ..........................95 ATALYTIC ONVERTER ............................95 ATALYST CHEF EXPRESS SCHEMATICS .................. 97 ........................98 ONTROL OARD CHEMATIC ..........................99 EATER CHEMATIC ......................100 ICROWAVE IRCUIT CHEMATIC ....................101...
  • Page 5 4 ..........................115 SSEMBLY EVEL...
  • Page 6 INDEX...
  • Page 7 SAFETY INSTRUCTIONS...

  • Page 8: Important Safety Instructions

    SAFETY INSTRUCTIONS Important Safety Instructions WARNING: When operating this oven, strictly adhere to the following safety precautions to reduce the risk of burns, electric shock, fire, injury, damage to oven or property near oven, or possible exposure to excessive microwave energy. General Safety Instructions •...

  • Page 9: Grounding Instructions

    WARNING: To reduce the risk of electrical shock, the unit must be properly grounded. Power Cord Replacement If the power cord is damaged in any way, is must be replaced by the manufacturer (Pratica Inc.), an authorized service agent, or qualified personnel.
  • Page 10 SAFETY INSTRUCTIONS Precautions To Be Observed Before And During Servicing To Avoid Possible Exposure To Excessive Microwave Energy (a) Do not operate or allow the oven operated with the door open. (b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source and make repairs as necessary: (1) Interlock operation, (2) proper door closing, (3) seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or loosening of hinges and latches, (5) evidence of dropping or abuse.
  • Page 11 SPECIFICATIONS & INSTALLATION...
  • Page 12 SPECIFICATIONS & INSTALLATIONS Spec Sheet...

  • Page 13: Electric Specifications

    Certifications Electric Specifications Chef Express Voltage Frequency Power Circuit breaker Consumption 208V 60Hz 6.2kW 4.3kW/h 240V 60Hz 7.2kW 5kW/h Oven Dimensions Height: 25” (636mm) Width: 20.9” (532mm) Depth (footprint): 21.4” (544mm) Depth: 31.7” (806mm) Volume: 0.74 cu/ft (21 Liters) Installation Instructions Please read the following instructions carefully.
  • Page 14 WARNING: This unit weights approximately 194 lbs. (88kg). Never attempt to lift this unit with fewer than 2 people. WARNING: The oven must be properly installed on a level surface at all times. Pratica Inc. will not recognize damage from a fallen oven as a warranty and may void warranty all together.

  • Page 15: General Instructions

    • To facilitate the oven maintenance, Pratica Inc. recommends a space os at least 30in between the right side of the equipment and the wall. • Do not allow the vents on the back or bottom of the unit to be blocked or restricted.
  • Page 16 DAILY CLEANING & QUARTERLY MAINTENANCE...
  • Page 17 DAILY CLEANING & QUARTERLY MAINTENANCE...

  • Page 18: Daily Cleaning

    DAILY CLEANING & QUARTERLY MAINTENANCE Daily Cleaning Please follow the steps below when cleaning the oven. Make sure to use non-caustic cleaners as they will not cause damage the oven or components. If damage occurs to unit or components due to incorrect cleaner, that will be considered a non-warranty service call.
  • Page 19 Step 4: Cleaning Catalyst WARNING: The Catalytic Converter must remain inside the oven during operation. Only clean when the unit is not in use. • Remove the oven rack and bottom jetplate. (Refer to step 1 & 2 for instructions on how to remove the rack and jetplate). •...
  • Page 20 DAILY CLEANING & QUARTERLY MAINTENANCE Step 7: Cleaning the Oven Cavity • Apply oven cleaner to a dry cloth or scrub pad and wipe down the sides of the cavity. • If large buildup occurs, you may spray the cleaner directly in the affected area and allow to sit for a small period of time to allow cleaner to break u buildup.

  • Page 21: Quarterly Maintenance

    Step 12: Cleaning Oven Exterior • If any stains have formed on exterior, wipe away with damp cloth or towel. • You may also spray cleaner on a dry cloth and wipe affected area to remove stain. • Make sure not to spray cleaner directly on exterior of oven. •...
  • Page 22 DAILY CLEANING & QUARTERLY MAINTENANCE Step 4: Removing Rear Vent Catalyst • With the use of a Phillips Screwdriver, remove al 8 screws holding the rear catalyst housing. • Support the housing with your hand prior to removing all screws. •...
  • Page 23 Step 8: Accessing Cooling Fans • If there is excessive build u on cooling fans, remove all Phillips screws around the outer edge of the rear panel. • Remove the rear panel completely to gain access to both cooling fans. •...
  • Page 24 THEORY OF OPERATION...
  • Page 25 THEORY OF OPERATION...
  • Page 26 THEORY OF OPERATION Chef Express Technology The Chef Express oven uses a combination of high speed air convection and microwave energy to heat and cook food faster than traditional cooking methods. With the use of a single blower fan, air enters the cavity from the top and distributes evenly over the product and forces down through the hokes of the bottom jetplate for even cooking.
  • Page 27 Characteristics of Microwaves What are microwaves? Before understanding the microwaves, we need to know what waves are. Physics describes a wave as a disturbance that spreads in a medium (space or mass). When a stone is tossed into a lake or body of water, we can observe the waves that spread from the point where the stone hits the water.
  • Page 28 THEORY OF OPERATION The electromagnetic wave is classified in a scientific scale called Electromagnetic Spectrum. Observing the spectrum below, the communication waves have a relatively long length and a low frequency. As we move down the spectrum, the length of the waves become smaller and the frequency becomes higher (ex.
  • Page 29 Microwaves are a type of radiant energy. As well as radio waves, visible light and infrared, the microwaves are part of the electromagnetic spectrum, i.e., it is a form of electromagnetic radiation. They are classified as non-ionizing radiation, because unlike x-rays and Alpha, Beta and Gamma rays, its effects are strictly thermal and therefore do not after the molecular structure of the item that is being irradiated.
  • Page 30 THEORY OF OPERATION How do the microwaves heat the food? The food is formed by bipolar molecules, that is, they possess a positive and a negative pole. For example, water in its composition has hydrogen and oxygen which are positive and negative. Water molecule In normal circumstances, the bipolar molecules of a food are disorderly placed.
  • Page 31 Why is the heating in the microwave oven faster than in the conventional stoves and ovens? When food is cooked over a stove, we must first heat the surface, the container, and finally, the food. When cooking inside of s traditional oven, it must first heat the air in the internal cavity, then the ovens walls, shelves and finally, the food.
  • Page 32 OVEN CONTROLS AND COOKING...
  • Page 33 OVEN CONTROLS AND COOKING...

  • Page 34: Control Panel

    OVEN CONTROLS AND COOKING Control Panel 1. Digital panel 2. Play button 3. Up/Down Arrow keys 4. Numerical keypad 5. Temperature control 6. USB function 7. Warning/ Heater 8. Return Key 9. Ok button 10. Manual cook mode 11. Cool down mode 12.
  • Page 35 Cooking The unit has a General Market menu installed from factory and is ready to operate out of the box. The end user can delete or edit these recipes to their own preference. New menu settings can be uploaded using a USB drive or inputting manually. Temperature Set Up/ Preheating 1.
  • Page 36 OVEN CONTROLS AND COOKING 4. The oven will display Preheating when warming up. 5. The oven has a factory Heat Soak period of 5 minutes. To change this time, turn unit off and press the Cool Down and On/Off keys at the same time. Use the Up/Down arrow keys to change from 0- 15 minutes.
  • Page 37 Cooking the Food 1. Select the food category by pressing the numerical button associated with category. Example: Press the number 3 to select Sandwich category. (Note: The Up or Down arrow keys can be pressed to view categories 5-8.) 2. The following message will appear while the cook cycle is processing 3.
  • Page 38 OVEN CONTROLS AND COOKING 4. Cook More Option: After each cook cycle, you will be able to select additional cook time if desired; ex.+10s, +20s, +30s. (Note: The oven only gives 10 seconds to make selection before going back to normal menu screen.) 5.

  • Page 39: Creating Recipes

    Creating Recipes When creating a recipe, all the variables mentioned earlier should be considered. The microwaves and the air speed are the critical factors for a successful preparation. To get faster results in the recipe creation, we suggest to begin programming at 1/10 of the total time of preparation used in a conventional process.

  • Page 40: Edit Mode

    OVEN CONTROLS AND COOKING Edit Mode From Edit Mode, the operator can create, change, or delete menu settings and rename category and item names. Follow these steps to access Edit Mode: 1. While the oven is turned off, press and hold the Down arrow and On/Off keys at the same time.
  • Page 41 4. The oven will require a password to make any changes. The default password is 123 and then press Enter. 5. Editing the Category will only allow you to change the name of the selected Category. Use the numerical keys to name the category. 6.
  • Page 42 OVEN CONTROLS AND COOKING 8. The Recipe Step screen will allow the end user to create/edit a menu with the ability to add up to 6 steps in the cooking process. 9. Each stage has 4 categories, as shown below. Starting from the top down, the options are time, chamber temperature, RI resistance temperature and blower speed.
  • Page 43 Importing / Exporting Menu a) To import or export a menu, remove the black cover under the door, lift the rubber tab of the USB terminal, and insert the USB drive while the unit is on and the menu is displayed. Black cover b) Press c) Using the alphanumeric keypad, press option 2 or 3...
  • Page 44 OVEN CONTROLS AND COOKING How to Load Firmware on Chef Express Step 1: Turn the oven off and disconnect the power plug from the wall. Remove the side panels and top cover. Step 2: Disconnect the USB cable from the display control board. See illustration.
  • Page 45 Step 3: Connect the ribbon cable of the black box to the display control board. See illustration. Please note the orientation when installing the ribbon cable. See illustration. • Blue side should be up! • Empty pin up! Step 4: Connect the USB connector from the black box to a computer. Wait approximately 2 minutes for the drivers to download.
  • Page 46 OVEN CONTROLS AND COOKING Step 6: Open the folder and choose “GRAVA_EXPRESS_G3_STD”. Step 7: Command prompt screen will open and start the loading process. See illustration.
  • Page 47 Step 8: Once the file transfer is complete, the following screen should appear. Step 9: Close the command prompt screen and remove the ribbon cable from the display control board. Reconnect the oven USB cable back to the display control board. See illustration. Step 10: Unplug the power cord from wall and wait 2 minutes before reconnecting.
  • Page 48 TEST MODE...
  • Page 49 TEST MODE...

  • Page 50: Information Screen

    TEST MODE Thermocouple Temp Readings To view the Thermocouple Temperature Readings, press and hold the number 1 and On/Off keys at the same time from the oven off position. • T.CHAMBER = The temperature inside the cook cavity. • T.CHAMBER RI = The temperature of the bottom IR element. Information Screen To view the Information Screen, press and hold the number 2 and the On/Off keys at the same time from the oven off position.
  • Page 51 On/Off keys at the same time from the oven off position. • RANGE TEMP = Allows to toggle between Fahrenheit and Celsius. • LANGUAGE = The Chef Express has four available language selections which are English, Portuguese, French, and Spanish.
  • Page 52 TEST MODE Frequency Inverter Fault Log To view the fault log for the Frequency Inverter, press and hold the number 5 and the On/Off keys at the same time from the oven off position. Count Error Inverter - The Inverter error code logs 3 types of malfunctions that happen within the Inverter.

  • Page 53: Magnetron Test

    Resetting Inverter Errors: To reset the Inverter Errors back to zero, press and hold the 1 and 3 keys simultaneously. The display screen will turn all blue and the count will be zeroed. Press to exit. The control board does not display the exact failure that occurred. To identify the exact error code, the inverter itself must be checked.

  • Page 54: Keypad Test

    TEST MODE Control Board Over Temp Count To view the Control Board Over Temperature Count, press and hold the number 7 and the On/Off keys at the same time from the oven off position. • TEMP BOARD = The amount of times the board has registered a temperature of 149 degrees Fahrenheit.
  • Page 55 MICROWAVE SYSTEM...

  • Page 56: How It Works

    MICROWAVE SYSTEM The Microwave System The Microwave is the most complex system in the oven. Extreme caution must be taken during servicing to protect both the operator and technician. The Microwave portion of the unit consist of several components that make up a left and right system. For safety precautions, both left and right microwave systems utilize a 20A fuse that will blow if an over-current situation occurs shutting off the microwave system immediately preventing further component damage.
  • Page 57 Door and Door Switches The Chef Express oven door utilizes a choke design. Door Adjustments Screws This design protrudes into the oven cavity slightly to improve the microwave sealing capabilities and functionality. The ovens leave the factory only after conforming to all the stringent testing required by multiple governing agencies.

  • Page 58: Door Switches

    MICROWAVE SYSTEM Door Switches The Chef Express oven utilizes three independent door switches to monitor the position of the door during microwave operation. The switches are referenced throughout this section as well as the wiring diagram as: Primary, Secondary, and Monitor.
  • Page 59 Door Switch Adjustments LED lights are used on the control board to indicate the position of the contacts of the three door switches. When the LED is illuminated, the switch position is opened and vice versa. The control board identifies the LED’s as SW1 (Primary) and SW2 (Secondary). The LED’s will illuminate when the over power is connected, (and the door is opened).
  • Page 60 MICROWAVE SYSTEM The proper distance to adjust the Primary and Secondary switches is 0.040” (1.0mm). This distance is measured between the switch body and the metal paddle. At this distance, the opening sequence of the three switches is correct and the microwave emission are well within the safety specifications. The Monitor switch is located on the left side of the oven and is actuated in the same manner.
  • Page 61 Components Magnetron Thermostat 1 and 2 The bimetal is mounted on the Magnetron chassis as shown in picture. This device is utilized to monitor the Protection magnetron temperature to prevent the magnetron Thermostat from overheating. These thermostats are self re- setting.
  • Page 62 MICROWAVE SYSTEM Microwave Relay The microwave relay is responsible for energizing the magnetrons by sending power to the high voltage transformers. The control board is monitoring the position of the door through the primary and secondary door switches (SW1 & SW2). If either one of these switches open the board will de- energize this relay.
  • Page 63 Micro Door Switches The SW1, SW2, and SW3 switches are activated by the opening and closing of the door. A signal is sent to the control board when the door switch is either open or closed. Door Switch Test 1) Unplug unit and remove both side panels of the equipment. 2) Disconnect the door switches wires.
  • Page 64 MICROWAVE SYSTEM How to Take an Amp Draw If any component from the microwave circuit fails or the food is not cooking properly, the first thing that should be done is take an amp draw on the CT wire. The target amp draw on both circuits for a 208V unit is between 14-15 amps, a unit supplied with 240V will be between 13-14 amps.
  • Page 65 High Voltage Transformer The HV transformer of the microwave circuit is formed by three windings. The primary low/line tension winding (208/240V), the secondary low tension/voltage winding (3.6V) and the secondary high tension/voltage winding (2000V), as shown in the scheme below. The secondary low voltage winding (3.6 volts) acts as a filament transformer and begins to energize the magnetron by heating the cathode.
  • Page 66 MICROWAVE SYSTEM Testing Primary Winding (208/240V) 1) Remove the rear panel from the unit. 2) Unplug the oven and wait 5 minutes for the high voltage capacitor to discharge or discharge manually by grounding each capacitor terminal. 3) Unplug the wires from the HV transformer terminals. 4) With an ohmmeter, measure the resistance across the terminals of the primary as shown in picture on the right.
  • Page 67 High Voltage Capacitor The capacitor utilized in the microwave circuit stores energy during half of the power cycle. It releases it during the other half of the cycle and aids the transformer to produce the 4.000V of continuous current to the Magnetron. The capacitor has an internal drainage resistor (10MΩ) to assist with discharging when power is cut off.
  • Page 68 The diode transforms the alternating current into continuous and prevents the filament voltage from becoming positive. The diode utilized in the Chef Express oven is of 16KV/750mA.
  • Page 69 Magnetron The Chef Express is equipped with two magnetrons in the microwave circuit. The structure of the Magnetron is basically composed of anode, filament (cathode), and the antenna. The anode is a hollow iron piece with several open cavities which are constituted by an even number of flaps pointing to the filament.
  • Page 70 MICROWAVE SYSTEM Powerful magnets are placed above and underneath the anode to generate a magnetic field along the length of the antenna. The magnetic field causes the electrons to follow a curved path around the cathode and the anode as seen in the picture below. MAGNET MAGNET As the electrons pass by the cavities, the cavities begin to resonate and emit microwave radiation.
  • Page 71 Testing Magnetron WARNING: Never attempt to measure high voltage directly. Death or serious injury could result. Always make sure to discharge the capacitor manually before commencing repair. 1) Remove both side, back and top covers from the unit. 2) Unplug the oven and discharge the capacitor manually by grounding each capacitor terminal. 3) Look for physical damage to the component.
  • Page 72 1.0mW/cm2 and greater than 5.0mW/cm2 for proper documentation by the field technician. The Chef Express oven utilizes a door choke design to efficiently seal the microwaves in the oven cavity. The technician needs to inspect the door surfaces for debris build up and remove any build up that may have accumulated between the door and the oven cavity surfaces.
  • Page 73 The magnetrons are equipped with an additional RF RF Gasket gasket that is placed around the antenna and the existing magnetron gasket. This additional gasket must have both ends of the material meet without any gaps to ensure a proper seal. The purpose of these gaskets is to provide the seal between the magnetron and the waveguide.
  • Page 74 MICROWAVE SYSTEM Testing for Microwave Leakage An RF leakage test should be performed after the following service tasks: • Door removal, replacement and/or adjustment • Waveguide removal and/or replacement • Magnetron removal and/or replacement • Door switch adjustment and/or replacement WARNING: This procedure requires work when the oven surfaces are extremely hot.
  • Page 75 IMPINGEMENT SYSTEM...

  • Page 76: Blower Motor

    The Chef Express impingement system utilizes different components to heat, filter and recirculate air into the cook cavity rapidly. Blower Motor The Chef Express oven utilizes a three-phase motor to spin the turbine clockwise and is controlled by a frequency inverter (Speed Control). Testing Blower Motor WARNING: The blower motor is located on the back of the unit in between the microwave circuits.
  • Page 77 Frequency Inverter (WEG CFW 100) The Chef Express oven regulates the speed of the blower motor the frequency. This inverter utilizes a data communication protocol called MODBUS to communicate with the main control board. The picture below shows the connections of the frequency inverter.
  • Page 78 IMPINGEMENT SYSTEM Frequency Inverter Troubleshooting The frequency inverter is in constant communication with the electronic board. If the control board registers a problem (ex. Lost communication), the control board resets the inverter to fix the problem. The electronic board will try to reestablish the communication with the frequency inverter. If the reset fixes the issue, the oven will continue with regular functioning.
  • Page 79 The following table shows the description of each status as well as the indication in HMI display. P006 Status Description READY Indicates the inverter is ready to be enabled. Indicates the inverter is enabled. Indicates the incoming voltage is too low for operation (under voltage) and will not accept the enabling command.
  • Page 80 IMPINGEMENT SYSTEM The following table shows the main failures and alarms that may occur in the inverter. Failure / Alarm Description Probable cause A046 - High load in the Blower motor overload alarm. Defective blower motor. blower motor shaft. Temperature in lGBT’s high (P030 > 230F / 110C).

  • Page 81: High Limit Thermostat

    High Limit Thermostat The high limit thermostat has an automatic reset bulb and does not need to be manually pushed. There are two high limit thermostats installed on the right side of the unit next to the heater breakers to protect the convection heater and Infrared element. The high limit bulbs are installed outside of the bottom chamber surface and on the rear next to the convection heater.

  • Page 82: Convection Heater

    IMPINGEMENT SYSTEM Convection Heater The Chef Express oven utilizes a 3000W, 208/240V (3X1000W) circular convection heater that is installed inside the rear chamber around the blower turbine. Testing Convection Heater 1) Remove the side covers and top oven panels. 2) Look for any physical damage to the heater or wires. If any damage is seen, remember to unplug the unit before continuing.
  • Page 83 IR Element The bottom infrared heater is a sheathed-style heater rated at 3,000 watts at 208V AC. The bottom heater is controlled by the heater contactor located on the right side of the unit. Testing IR Element 1) Remove the right and left side panels of the unit. 2) Look for any physical damage on the heater element or wires.

  • Page 84: Testing Temperature Sensors

    IMPINGEMENT SYSTEM CC/IR Temperature Sensors The Chef Express oven utilizes two type J temperature sensors. The sensors are responsible for registering the temperature for the cook cavity and IR element and relaying the information to the main control board. Testing Temperature Sensors When an error in the cook chamber sensor occurs, the board will stop the operation of the oven and will display the following fault code on the screen.
  • Page 85 To test the temperature sensors, follow the steps below. Unplug the oven 1. Remove both side and top panels from the unit 2. Visually check for physical damage to the sensor or wires. 3. Remove both wires from the main control board and test for continuity. •...
  • Page 86 CONTROL SYSTEM...
  • Page 87 CONTROL SYSTEM...
  • Page 88 CONTROL SYSTEM Main Control Board/Display The control board signals each oven component based on commands sent from the keypad that were selected by the operator. The display is attached to the control board and will come together if the control board is ordered. The board has a current sensor which measures the amp draw of the microwave circuit through the brown CT wire looping through it.
  • Page 89 Testing Main Control Board The main control board sends and receives signals from components throughout the unit. The diagram above shows all the wires connected to the control board and which component they belong to. Always verify for physical damage or loose connections before continuing to check continuity, voltage, etc.

  • Page 90: Testing Keypad

    Testing Keypad The Chef Express oven has the ability to test each individual button of the keypad from test mode. To access the keypad test, follow the steps below: 1. From the oven off mode (blank screen), press and hold the number 0 and turn the unit on by pressing the On/Off key.

  • Page 91: Testing The Speaker

    Speaker The speaker provides audible feedback to the oven operator, for example when a cook cycle is completed. Testing the Speaker If the speaker is no longer audible, check the speaker wires to make sure they are secure the terminals. If wires are secure, check the wires for DC voltage coming from the control board. If DC voltage is present, replace the speaker.
  • Page 92 POWER COMPONENTS...
  • Page 93 POWER COMPONENTS...

  • Page 94: Emi Filter

    POWER COMPONENTS EMI Filter The EMI Filter helps suppress the amount of RF interface through the electrical system that is emitted by the microwave circuit. The EMI filter is installed on back of the unit below the blower motor. Testing EMI Filter To test the EMI Filter, test across both terminals for incoming and outgoing AC voltage to verify that the voltage is passing through correctly.

  • Page 95: 12Vdc Power Supply

    12VDC Power Supply The DC Power Supply outputs 12V DC to the main control board. Testing Power Supply WARNING: Make sure to connect the positive (red) Power Supply wire to terminal 1 and negative (black) to terminal 2 on the control board. Switching polarities will cause damage to the control board.

  • Page 96: Ventilation System

    POWER COMPONENTS Ventilation System The Chef Express oven ventilation system uses two 3400 RPM cooling fans (dimensions: 7in/172mm x 6in/150mm) that exhaust all of the hot air from the magnetrons and electronic compartment. Testing Cooling Fans WARNING: For safety purposes, manually discharge capacitors before troubleshooting cooling fans due to proximity.
  • Page 97 Testing Control System Fuses The fuses are mounted on a din rail and can be removed with the use of a flathead screwdriver. 1) Unplug the oven and remove the right-side panel. 2) With a flathead screwdriver, locate the tab on the bottom and push down with the screwdriver.
  • Page 98 FILTERING SYSTEM...
  • Page 99 FILTERING SYSTEM...

  • Page 100: Air Filter

    FILTERING SYSTEM Air Filter The main purpose for the air filter is to prevent debris from entering the unit. The filter will block dirt, dust, lint, and other particles that can cause build up in the air vent system and other components. The filter is located on the bottom of the unit and can be removed by pulling the filter and tray out towards the front of the oven.

  • Page 101: Catalytic Converter

    475°F (246°C). CAUNTION: The catalyst can only be cleaned by approved non-caustic oven cleaner provided by Pratica Inc. and rinsed with distilled water. The catalytic converter can become seriously damaged if cleaned with any other product.
  • Page 102 CHEF EXPRESS SCHEMATICS...
  • Page 103 CHEF EXPRESS SCHEMATICS...

  • Page 104: Control Board Schematic

    CHEF EXPRESS SCHEMATICS Control Board Schematic...
  • Page 105 Heater Schematic...
  • Page 106 CHEF EXPRESS SCHEMATICS Microwave Circuit Schematic...
  • Page 107 Blower/Motor cooling Fan Schematic...

  • Page 108: Pictorial Diagram

    CHEF EXPRESS SCHEMATICS Pictorial Diagram...
  • Page 109 EXPLODED VIEW PARTS LIST...
  • Page 110 EXPLODED VIEW / PARTS LIST Assembly Level 1...
  • Page 111 Assembly Door...
  • Page 112 EXPLODED VIEW / PARTS LIST Assembly Panel...
  • Page 113 Inverter...
  • Page 114 EXPLODED VIEW / PARTS LIST Assembly Level 2...
  • Page 115 Door Hinge Assembly RHS...
  • Page 116 EXPLODED VIEW / PARTS LIST Door Hinge Assembly LHS...
  • Page 117 Assembly Level 3...
  • Page 118 EXPLODED VIEW / PARTS LIST Assembly Motor...
  • Page 119 Assembly Terminal Block Support...
  • Page 120 EXPLODED VIEW / PARTS LIST Assembly Power Components Support...
  • Page 121 Assembly Level 4...
  • Page 122 For service or information: Pratica Products, Inc – USA 675 Town Square Boulevard, Suite 200 Garland, TX 75040 1-214-299-7726 info@praticausa.com www.praticausa.com Pratica Products, Inc - USA 675 Town Square Boulevard, Suite 200 © 2018 Pratica Products, Inc - USA Garland, TX 75040...

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