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Aromat Cafe D420 Service Manual

Coffee dispenser
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D420 Service Manual
D420

Coffee Dispenser

Service Manual
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  • Page 1: Coffee Dispenser

    D420 Service Manual D420 Coffee Dispenser Service Manual...
  • Page 2 DASS Manufacturing Ltd. SBC House, Restmor Way, Wallington, Surrey, SM6 7AH, United Kingdom. Tel: +44 (0)20 8669 8012 Fax: +44 (0)20 8669 9529 Email: support@aromat-uk.com Web: www.aromat-uk.com © Copyright 2006, DASS Manufacturing Ltd. All rights reserved Document No: TD D420 03 001...

  • Page 3: Table Of Contents

    Understanding Fault Codes The Control Panel Setup Mode Machine Supplied User Settings Engineer Configurable Settings Making Changes Putting the D420 into Engineer Setup mode The Engineer Menu Structure Machine Supplied Settings Obtaining Replacement Parts Illustrated Parts Catalogue Using Web Site...
  • Page 4 Servicing Control Panel Removing / Refitting Control Unit Assembly Updating the PCB Processor Chip Replacing the Control PCB Replacing Set Up or Prime/Flush Membranes Replacing the Display Unit Servicing the Cooler Unit Removing / Refitting Cooler Unit Checking Product Detect System Checking for Channel Changeover Replacing Peristaltic Pumps Adjusting a Peristaltic Pump...

  • Page 5: Introduction

    (html) web pages. To identify the parts referred to in this manual, you may find it useful to view the D420 Illustrated Parts Catalogue, available from the web site.

  • Page 6: Understanding Fault Codes

    1.2 Understanding Fault Codes The table below describes the D420’s Fault Codes: Fault Description / Cause Overflow Too much water in tank Float Fault Logical fault. Overflow detected but insufficient water in tank. Possible stuck float or faulty switch. Thermostat Trip Thermostat has detected boiler overheat.

  • Page 7: Setup Mode

    D420 Service Manual 1.4 Setup Mode To view the user settings, put the machine into SETUP MODE by turning the Mode keyswitch. SETUP MODE Press Selection The menu options are: • Selection • Speed • Strength • Set Channel? Scroll through the options by pressing the Enter button.

  • Page 8: Engineer Configurable Settings

    All replacement parts used in the D420 dispenser should be approved by DASS Manufacturing Ltd. 2.2 Putting the D420 into Engineer Setup mode Turn the Mode keyswitch to put the machine into SETUP MODE.

  • Page 9: The Engineer Menu Structure

    • Peris Speed Offset • Enable / Disable product Sensors • Enable / Disable Leak Detect The D420 Installation Guide provides basic instructions for changing these settings. 2.4 Machine Supplied Settings The machine was configured in the factory with the following user settings:...

  • Page 10: Obtaining Replacement Parts

    3.4 Locating Part Illustration, Description and Number Select Parts Lists from the left menu and then D420 at the top of the Navigation page. Select the version to reach the Parts Lists overview page. Clicking on an assembly image will open a new window with an annotated exploded view of that assembly.

  • Page 11: Preparing The D420 For Servicing

    All tools required should be to hand before undertaking any major dissembling. 4.2 Noting Machine Settings Before undertaking any maintenance on the D420, noting down all of the current user and engineering mode settings will enable you to return the machine to service exactly as the original settings.

  • Page 12: Removing The Casing Panels

    4.3 Removing the Casing Panels WARNING: Before removing any of the Casing Panels the machine MUST be isolated from the mains power supply. Note: The machine should only be powered ON with the panels removed if the engineer can satisfy himself that it is safe to do so. Tools required: No.

  • Page 13: Disconnecting / Reconnecting Power Supply

    10mm AF socket Socket holder Gland Spanners To disconnect the D420 from the Mains Power Supply: Power OFF and isolate the machine from the Mains Power Supply. Remove the Front Panel as described in Section 4.3. Undo the four M4 x 12mm screws and remove the PSU Connection Cover.

  • Page 14: Disconnecting / Reconnecting Water Supply

    4.7 Draining the Tank WARNING: Water in the tank may scold. Note: When the D420 Dispenser is powered OFF, water will not flow through the Water Inlet Valve. DO NOT shut off the water at the supply valve and leave the machine powered ON, as this could damage the Water Inlet Valve.

  • Page 15: Draining Water Inlet Hose Pipe

    D420 Service Manual 4.8 Draining Water Inlet Hose Pipe Even though the tank may be drained, water will still remain in the water inlet hose pipe. Tools required: Metal hose clamp (supplied with the machine) One litre container Towel or absorbent cloth...

  • Page 16: Servicing Tank And Water Supply

    Servicing Tank and Water Supply 5.1 Replacing the Water Inlet valve Note: It is not necessary to drain the water tank to replace the Water Inlet Valve. Tools required: Metal hose clamp (supplied with the machine) 1 1/8” AF Spanner No.

  • Page 17: Setting Water Outlet Valve Flow Rate

    D420 Service Manual Follow the procedure in Section 4.7 to lower the water level to below the valve tube. As the water drains out, you should be able to see the top of the water in the valve body as the level drops. Once this level appears to stop dropping, run off another bucket of water to ensure that the level is below the valve.
  • Page 18 Note: If all valves are being replaced, first adjust and set Outlet Valve 2, then Outlet Valves 1 and 3. Outlet Valve 4 uses the Hot Water Only button and for maximum flow, should be adjusted so that the screw is flush with the cylinder face. Tools required: Calibrated 2 gallon (10 litre) container or bucket (see Appendix A) Timer with second hand...

  • Page 19: Replacing Heating Elements

    D420 Service Manual Repeat the operations 5 and 6 until the correct amount (10 litres) is dispensed. To adjust the flow rate for Water Outlet Valve 2: With the machine in SETUP MODE, press Product Select Button 1 and then the Enter button to scroll down until Speed is displayed and set to Speed=1.
  • Page 20 Drain the tank as described in Section 4.7. Undo the eight M4 x 10mm countersunk screws and remove the Element Access Cover fitted to the RH side casing panel. Silicon Element 3 Sleeve Element 2 Link Element 1 Tab and mark the cabling connected to the heater element to ensure they are reconnected to the new element/s correctly.

  • Page 21: Replacing Boiler Temperature Control Thermister

    D420 Service Manual 10 Allow the machine to refill with water and check for any leaks. 11 Power OFF and isolate the machine from the Mains Power Supply. 12 Refit the Element Access Cover and Front Panel. 5.5 Replacing Boiler Temperature Control Thermister The boiler temperature control thermister is accessible from behind the LH Cooler Unit.
  • Page 22 Tools required: Submersible Thermometer (min 12” probe) Ohm meter with long probes Terminal Screwdriver No. 2 Pozidrive Screwdriver To calibrate the Thermister: Power OFF and isolate the machine from the Mains Power Supply. Remove the Top Panel as described in Section 4.3. Remove the Silicon Stopper in the tank lid.

  • Page 23: Replacing Boiler Over Temperature Thermostat

    D420 Service Manual 16 Match the temperature shown on the display panel to the thermometer reading by turning the screw on the Trim Pot (anticlockwise to raise temperature displayed and clockwise to lower temperature displayed) by approx. 1°F (.5°C) per full turn.

  • Page 24: De-Scaling The Tank

    Remove the Top Panel as described in Section 4.3. Float switch (overflow) Float switch (water level) Carefully label and disconnect the cables to the microswitch. Undo the two screws securing the microswitch to the bracket, being careful not to lose the securing nuts. Retain the screws and nuts. Slide the switch arm out of the float rod eye.

  • Page 25: Cleaning Water Outlet Valves

    D420 Service Manual Undo the ten M4 x 8mm screws and carefully remove the Tank Lid Cover. Slowly pour the descaling agent into the tank. It will immediately begin to effervesce. Wait for the minimum required time recommended by the scaling agent manufacturer before draining the tank as described in Section 4.7.
  • Page 26 Solenoid Housing Silicon Plunger Valve Body Studs Taking care not to pull the shaft out of the solenoid body, prize off the silicone plunger. Note: There is a small spring inside the shaft which may be lost if the shaft is allowed to come out of the solenoid body.

  • Page 27: Servicing Control Panel

    D420 Service Manual Servicing Control Panel 6.1 Removing / Refitting Control Unit Assembly The Control Unit Assembly is secured by a thumbscrew connecting it to the retaining bracket fitted to the chassis cross tie plate and a chrome handle fitted to the Cooler platform, on which the Control Unit pivots Refer to the Control PCB layout diagram in Section 9.3 before disconnecting the looms.
  • Page 28 section 5.6) and reset the top temperature setting. Tools required: No. 2 Pozidrive Screwdriver Stepladder To replace the Control PCB Processor Chip: Ensure that all settings are noted as described in Section 4.2. Power OFF and isolate the machine from the Mains Power Supply. Remove the Casing Top Cover as described in Section 4.3.

  • Page 29: Replacing The Control Pcb

    D420 Service Manual 6.3 Replacing the Control PCB This can be undertaken without removing the Control Unit Assembly. Refer to the Control PCB layout diagram in Section 9.3 before replacing the Control PCB. Note: An earthing wristband should be worn when there is a risk of touching any of the components on a printed circuit board.

  • Page 30: Replacing The Display Unit

    To remove and replace a membrane panel: Power OFF and isolate the machine from the Mains Power Supply. Remove the Top Cover panel as described in Section 4.3. Undo the Cooler Unit door if replacing a Prime/Flush membrane Very carefully disconnect the Set-up or Prime/Flush membranes. Using a blunt Stanley knife blade, carefully ease up the corner of membrane panel, pull off with fingers and discard.
  • Page 31 D420 Service Manual or folded towel on the bench. Nylon Screws Display Panel Undo the four nylon screws securing the Display Panel to the raised studs on the Selection Box and carefully lift the Display Panel away. Note: there are fibre washers between the Display Panel and studs, which must be retained with the nylon screws.

  • Page 32: Servicing The Cooler Unit

    The D420 Cooler Units are handed but comprise identical components save for the door panel Label. You may find it useful to view the D420 Illustrated Parts Catalogue to identify the parts referred to in this procedure. A pdf version is available from the DASS Technical web site.

  • Page 33: Checking For Channel Changeover

    7.3 Checking for Channel Changeover When the concentrate can is empty in one channel, if configured to do so, the D420 will automatically select another channel from which to dispense. There are four options, which need to be checked: •...
  • Page 34 To check Channel Changeover for option 4 Identical: Follow instructions 1 to 6 in Section 7.2. Press the Enter button until the machine is in SETUP MODE. Press Selection button 1, scroll down to Set Volume and using the timer, set to dispense for 60 seconds.
  • Page 35 D420 Service Manual To check Channel Changeover for option 2+2 (Ch 1 & 2): Turn the Mode keyswitch to put the machine into SETUP MODE. Press PRIME 1 and then PRIME 2 to put the machine into ENGINEER SETUP mode.

  • Page 36: Replacing Peristaltic Pumps

    10 Press Product Select button 1. When the cup under channel 4 is empty. PRODUCT 4 LED should light and concentrate should be taken from channel 3. Product LEDs 4 and 3 should light in turn as the containers empty. It should not dispense from channels 1 and 2.

  • Page 37: Adjusting A Peristaltic Pump

    Install the new pump assembly by reversing the above procedure. Adjust the replacement pump as described in Section 7.5. 10 Before putting the new pump into service, with the D420 powered ON and in dispense mode, throroughly flush the product channel with a sanitizing agent, as described in Appendix D.
  • Page 38 To adjust a Peristaltic Pump: Open both Cooler Unit doors and remove any coffee concentrate. Press PRIME for the product channel of the pump to be adjusted and clear the concentrate from the tubes. Flush the product channel by using a 1 pint (50cl) container of hot water and pressing PRIME until the container is empty.

  • Page 39: Replacing Heat Pump

    D420 Service Manual 7.6 Replacing Heat Pump There is a heat pump assembly in each of the Cooler Units. To replace any of the heat pump componenets, the Cooler Unit must be removed from the dispenser. Tools required: 8mm AF socket and driver No.

  • Page 40: Servicing The Power Supply Unit

    Servicing the Power Supply Unit In order to access the D420 PSU components, the top and front panels will need to be removed. To gain easy access to these components, it may be preferable to remove the complete unit in order to work on a bench.

  • Page 41: Removing / Refitting Psu Cover Panels

    11 Carefully feeding the Power Loom behind the LH Cooler unit, lift out the entire D420 PSU Assembly and place on a bench. 12 Refit the D420 PSU Assembly by reversing the above procedure. 8.2 Removing / Refitting PSU Cover Panels Tools required: No.

  • Page 42: Replacing A Relay Or The Contactor

    Ease the LH End Cover into place and secure with two screws to the top Cover panel. Loose fit the remaining seven screws securing the Top Cover panel to the PSU Tray and On/Off Switch Bracket. Tighten the LH End Cover screws. If necessary, rotate the PSU assembly clockwise and refit the six M5 x 8mm hex set screws securing the PSU Assy.

  • Page 43: Replacing The Switched Mode Psus

    D420 Service Manual 8.4 Replacing the Switched Mode PSUs The Switched Mode PSUs are fitted to the On/Off Switch Bracket and can be replaced without removing the PSU Assembly from the machine. Note: The new 12v PSU will need to be adjusted after installing.

  • Page 44: Replacing The Psu Pcb

    To calibrate the 12v PSU: Disconnect both Cooler Unit looms at the Control PCB (see section 9.3). With the PSU plastic terminal cover removed, power ON the machine. Using a volt meter, measure across any red and any black terminal connection. Trim POT Adjust the POT to set the PSU as near to 12v as possible, but not lower than 12v.
  • Page 45 D420 Service Manual Rotate the PSU assembly anticlockwise to provide access to the LH End Panel screws and remove the LH End Panel. Disconnect Earth loom from PCB to the 12v Switched Mode PSU and PSU Tray. Earth Loom To Low Current...

  • Page 46: Technical Specifications

    Technical Specifications 9.1 General Specifications Height: 35.04 ins (89 cm) Depth: 23.23 ins (59 cm) Width: 31.10 ins (79 cm) Net weight: 278 lbs (126 Kg) Operating weight: 463 lbs (210 Kg) Power: 3 Phase Delta min. 30Amps (Low Current circuit) 440v - 480v –...

  • Page 47: Main Looms Diagram

    D420 Service Manual 9.2 Main Looms Diagram D420 Main Looms Tank Lid Boiler Top Temp Tank Outlet T/stat Valves Thermister Heater Elements Inlet Valve Control Hot Water Select Chassis LH Cooler RH Cooler Unit Fan Unit Fan Nozzle Control LH Cooler...

  • Page 48: The Control Pcb

    9.3 The Control PCB PSU Loom Outlet Valves Inlet Valve Sockets Socket Socket Tank Lid Loom Socket Thermister + Over Temp Control Panel Thermostat Loom Socket Loom Socket Trim Pot Hot Water Selection Processor Loom Socket Chip Fans Loom Socket LH Cooler RH Cooler Loom...

  • Page 49: Psu Wiring Diagram

    D420 Service Manual 9.4 PSU wiring diagram...

  • Page 50: A Calibrating A Suitable Container

    Appendix A Calibrating a Suitable Container Before adjusting the flow rate for a new outlet valve if a suitable container is not already calibrated, it will be necessary to mark the inside of a bucket with volume levels. Note: Because under normal conditions, the machine will be dispensing water at the maximum temperature, it is necessary that water from the boiler be used when calibrating the container or bucket.

  • Page 51: B Recommended List Of Tools

    D420 Service Manual Appendix B Recommended List of Tools Below are listed the tools referred to in this manual: 3mm terminal screwdriver 6mm flat end screwdriver No.1 Pozidrive screwdriver No. 2 Pozidrive screwdriver – 6” No. 2 Pozidrive screwdriver – 10”...

  • Page 52: C Machine Settings Form

    Peris Speed Offset: Pump 1 Pump 2 Pump 3 Pump 4 Leak Detect: Enabled Disabled Tick appropriate Box Settings Reset (Eng. sig.) Keep completed form with machine. Complete a new form if changes are made. Doc Ref No: TD D420 06 001...

  • Page 53: D Cleaning And Sanitising Instructions

    D420 Service Manual Appendix D Cleaning and Sanitising Instructions IN PLACE CLEANING SCHEME FOR D420 DISPENSER. CIeaning the dispenser and sanitising the concentrate systems should be undertaken on a daily basis. To avoid Injury. exercise caution when handling hot liquids. When handling chemicals exercise precautions as defined by the chemical manufacturer.

  • Page 54: Epsu Front Cover Label

    Appendix E PSU Front Cover Label...
  • Page 55 D420 Service Manual...

  • Page 56: Contact Information

    This document was written, illustrated and published by the MicroArt studio, Windsor, UK Contact Information DASS Manufacturing Ltd. SBC House, Restmor Way, Wallington, Surrey, SM6 7AH, United Kingdom. Tel: +44 (0)20 8669 8012 Fax: +44 (0)20 8669 9529 Email: sales@aromat-uk.com Web: www.aromat-uk.com www.aromat.de...

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