Air Top 2000 List of Contents Air Heater Air Top 2000 S D (Diesel) Air Top 2000 S B (Gasoline) Service and Repair Manual – Improper installation or repair of Webasto heating and cooling systems can cause fire or the leakage of deadly carbon monoxide leading to serious injury or death. – Installation and repair of Webasto heating and cooling systems requires special Webasto training, technical information, special tools and special equipment.
Air Top 2000 S List of Contents List of Contents 1. Introduction 1.1 Scope and Purpose................................................................................................................................. 101 1.1.1 1.2 1.3 1.4 Meaning of Warnings, Cautions, and Notes ............................................................................................ 101 Additional Documentation to be used...............................................................................................
List of Contents 7. Circuit Diagrams 7.1 8. General....................................................................................................................................................701 Servicing 8.1 8.2 8.3 8.4 8.5 8.6 General....................................................................................................................................................801 Work on the Air Heater ........................................................................................
Air Top 2000 S List of Figures List of Figures 501 502 General Failure Symptoms .............................................................................................................................501 Failure Symptoms during Operation ...............................................................................................................502 601 Adjustment of CO2 Contents ......................................................................................................................
List of Figures IV Air Top 2000 S
Air Top 2000 S 1. Introduction 1.1 Scope and Purpose This repair shop manual is intended to support familiarized personnel in the repair of the Air Top 2000 S. 1 1.4 Introduction Safety Information and Regulations The general safety regulations for the prevention of accidents and the relevant operating safety instructions have to be observed at all times."General Safety Regulations" beyond the scope of these regulations are detailed in the following.
1 Introduction The heater must not be installed in the passenger or driver compartments of busses. Should the heater nevertheless be installed in such a compartment, the installation box must be sealed tight against the vehicle interior. There must be sufficient ventilation of the installation box from the exterior in order not to exceed a maximum temperature of 40 °C in the installation box. At filling stations and fuel depots the heater must be switched off as there is a potential danger of explosion.
Air Top 2000 S 1 Introduction Metal lines must be used. These may not heat to more than 110 °C should there be the possibility of contact within the room interior. Protective devices against contact may be fitted. Should exhaust pipes be routed through rooms accommodating persons, these pipes shall be renewed after 10 years using genuine spare parts.
2 2. Air Top 2000 S General Description General Description The air heater Air Top 2000 S operates under the evaporator principle and basically consists of: - combustion and heating air fan - heat exchanger - burner insert with combustion tube - control unit A malfunction of the Air Top 2000 S is indicated by an error code displayed on the combination or standard timer. When equipped with the standard control dial, the operating indicator flashes.
Air Top 2000 S 2.2 2 Heat Exchanger 2.4 The heat exchanger dissipates the heat provided by combustion to the air delivered by the combustion and heating air fan. General Description Control Unit / Control Circuit Board The control unit/control circuit board is the central controlling unit for functional sequencing and monitoring of the combustion operation. A temperature sensor located on the control unit is used for temperature control.
2 2.5 Air Top 2000 S General Description Flame Sensor The flame sensor is a low-Ohm PTC resistor changing its resistance dependent on its heating by the flame. The signals are routed to the control unit for processing. The flame sensor monitors the flame operating condition over the complete duration of heater operation. 2.7 Temperature Limiter The temperature limiter protects the air heater against excessive operating temperatures.
Air Top 2000 S 3. Functional Description 3.1 Functional Description Air Top 2000 S 3.1.1 Control Element The control element is used to switch the air heater on and off, set the desired room temperature (air intake temperature between 10 °C and 45 °C), and to unlock a failure interrupt condition. The green LED indication is used to indicate the operating condition (LED permanently on) and an overheat condition (LED flashes). 3.1.2 Switch-On The control element is set to the desired room temperature.
3 Air Top 2000 S Functional Description 3.1.4 Heating Operation 3.1.7 Switch-Off During operation the combustion exhaust gasses flow through the heat exchanger charging its walls with combustion heat, which in turn is taken up by the heating air delivered by the heating air fan to be routed to the vehicle interior.
Air Top 2000 S 4. 4 Technical Data Technical Data Fuel for Air Top 2000 S B (gasoline): The fuel specified by the manufacturer must be used. As long as no threshold values are given, the following technical data are understood to include tolerances of ±10% usual for heaters at an ambient temperature of +20 °C and at nominal voltage and conditions. Fuel for Air Top 2000 S D (diesel/PME): The diesel fuel specified by the vehicle manufacturer must be used.
5 Air Top 2000 S Troubleshooting 5. Troubleshooting 5.1 General A malfunction of the Air Top 2000 S is indicated by an error code displayed on the combination or standard timer. When equipped with a standard control dial the operating indicator flashes. In addition a heater check out may be performed using a personal computer (refer to operating instructions PC air heater diagnosis).
Air Top 2000 S 5.3 5 Failure Symptoms during Operation The following table (Fig. 502) lists the possible failure symptoms as they might occur during the functional sequence of operation. In case of malfunction the failure is to be isolated and removed using this table. It is important to accurately identify the failure symptom.
5 Troubleshooting 5.4 Error Code Output When equipped with a combination or standard timer a malfunction will cause an error code output to the display of the timer for indication. NOTE When equipped with a control dial, the error code output is indicated by flashing of the operating indicator/error code indication. The number of flash pulses corresponds to the number indicated in the table below. After a quick pulse train there will always be an error code output.
Air Top 2000 S 6 Functional Tests 6. Functional Tests CAUTION Set potentiometer slowly; observe end positions. 6.1 General Adjustment may be performed at any electrical system voltage. This section describes the on-vehicle and off-vehicle testing of the air heater to check its proper operation. Clockwise rotation increases the fan speed and decreases the CO2 contents. Counterclockwise rotation decreases the fan speed and increases the CO2 contents.
6 6.3 Air Top 2000 S Functional Tests Components Testing CAUTION During electrical testing always ensure that the control unit and the component under test are electrically disconnected from each other. 6.3.1 Glow Plug Resistance Test During electrical testing of the glow plug using a digital multimeter, the following readings should be obtained: Glow plug 12 Volt (red) Resistance at 25 °C: 0.324 ... 0.360 Ω Test current: < 5 mA 24 Volt (green) 1.3 ... 1.44 Ω < 5 mA 6.3.
Air Top 2000 S 7 7. Circuit Diagrams 7.1 General Circuit Diagrams The air heater Air Top 2000 S may be operated using the control dial (rated value transmitter/switch) or with the control dial and a combination or standard timer. The circuit diagrams (Figs. 702 to 704) show the possible circuits 12 or 24 Volt with control element combination timer control element and standard timer Fig. 701 shows the terminal pin assignment.
7 Air Top 2000 S Circuit Diagrams 2 ? ? ? Item A1 A2 B1 B2 B3 E F2 H1 M S1 X1-X5 X6 X7 X8 X9 X11 X12 Y1 Nomenclature Air Heater Control Unit Flame Sensor Temperature Sensor Temperature Limiter Glow Plug Fuse 24V 10A/12V 15A LED green (in item S1) Motor Control Element Connection 2-pole Connection 8-pole Connection 4-pole Connection 2-pole Connection 2-pole Connection 6-pole Connection 1-pole Dosing Pump Remark Air Top 2000 S Wire Gauges 7.5 - 15 m 1.5 mm2 1.5 mm2 2.5 mm2 4.0 mm2 6.0 mm2 2.5 mm2 4.
Air Top 2000 S 7 Circuit Diagrams 1 2 ? ? ? Item A1 A2 B1 B2 B3 E F2 H7 Nomenclature Air Heater Control Unit Flame Sensor Temperature Sensor Temperature Limiter Glow Plug Fuse 24V 10A/12V 15A LED red (in item P) H8 Heating symbol in display (in item P) H9 M P1 S3 X1-X5 X6 X8 X9 X11 X12 X13 Y1 Light (in item P) Motor Combination Timer (1531) Switch Connection 2-pole Connection 8-pole Connection 2-pole Connection 2-pole Connection 6-pole Connection 1-pole Connection 12-pole Dosing Pump Remark Air
7 Air Top 2000 S Circuit Diagrams 1 2 ? ? ? Item A1 A2 B1 B2 B3 E F2 H7 Nomenclature Air Heater Control Unit Flame Sensor Temperature Sensor Temperature Limiter Glow Plug Fuse 24V 10A/12V 15A LED red (in item P) H8 Heating symbol in display (in item P) H9 M P2 S1 S3 X1-X5 X6 X7 X8 X11 X12 X13 Y1 Light (in item P) Motor Standard timer Control Element Switch Connection 2-pole Connection 8-pole Connection 4-pole Connection 2-pole Connection 6-pole Connection 1-pole Connection 12-pole Dosing Pump R
Air Top 2000 S 7 Combination Timer 1531 Grey Lights (1) (optional) Circuit Diagrams Black Battery Positive or Ignition Signal (10) Red Battery Positive (11) 12V 24V Brown Battery Negative (12, 4) 1 2 3 4 5 7 6 8 9 10 1 1 12 Adapter Harness P/N 9008440A Fig.
7 706 Circuit Diagrams Air Top 2000 S
Air Top 2000 S 8. Servicing 8.1 General 8 For reasons of the air heater’s functional reliability perform the following servicing: check heating air inlet and outlet for foreign matter and contamination. (Contaminated or clogged heating air ducts may lead to overheating and thus response of the temperature limiter). Clean air heater exterior (prevent the ingress of water). Examine electrical connections for corrosion of contacts and for security.
8 Air Top 2000 S Servicing 8.6.2 Fuel Supply The fuel is taken from the vehicle fuel tank or from a separate fuel tank. The values for maximum pressure at the fuel extraction point are shown in Fig. 801. At maximum pressure in fuel line 0.20 bar (2.9 PSI) 0.11 bar (1.6 PSI) 0.03 bar (0.44 PSI) At maximum negative pressure in fuel tank -0.10 bar (-1.45 PSI) -0.06 bar (-0.87 PSI) -0.02 bar (-0.29 PSI) 8.6.2.
Air Top 2000 S 8 Hole Pattern Servicing Fuel Tank Tap Gaskets 25 mm (1 in.) > 25 mm (> 1 in.) Tank Fitting Plate Fig. 802 Webasto Fuel Tank Tap * Use fuel tank tap only on metal fuel tanks Fig. 804 Fuel Tapping from Plastic Tank (tapping via fitting plate) Plastic Tank NOTE The fitting plate must be made of sheet metal! 8.6.2.2 Fuel Lines Gasket Fuel lines may only be steel, copper, or plastic lines made of unhardened, light and temperature stabilised PA 11 or PA 12 ( e.g.
8 Air Top 2000 S Servicing Connection of 2 Pipes with Hose 8.6.3.1 Installation Location The proper connection of fuel lines with hoses is shown in Fig. 805. It is advantageous to mount the dosing pump in a cool location. The ambient temperature must never exceed +20 °C during operation. Correct Dosing pump and fuel lines must not be installed in locations exposed to heat radiated by hot vehicle components. A heat shield is to be provided as required. Clamp 8.6.3.
Air Top 2000 S 8.6.5 Combustion Air Supply Combustion air must under no circumstances be extracted from rooms with persons. The combustion air inlet must not point towards the forward direction of motion. It must be located so that no clogging by contamination is to be expected. 8 Servicing Both lines must be routed away from the heater in a descending attitude. If this is not possible, a condensate drain hole ø 4 mm must be provided at the lowest point.
8 Air Top 2000 S Servicing 8.6.8 Electrical Connections 8.6.8.3 Connection Control Dial 8.6.8.1 Connection Air Heater, Control Dial The cable loom is prefabricated to connect to the control dial (rated value transmitter). For plug disconnection pull on terminal plug only (Fig. 812). By pulling on the cable loom the terminal plug is secured (self-locking). Electrical connection is according to Circuit Diagram Automatic Control (see Section 7). For connection of the cable loom the cover (see 9.2.1.
1 2 3 4 5 6 7 Control Dial Air Heater Dosing Pump and Damper Fuel Filter (Accessory) Fuel Connector Exhaust Muffler Fuse 7 1 6 2 3 4 5 Air Top 2000 S 8 Servicing Fig.
8 8.7 Air Top 2000 S Servicing Removal and Installation 8.8 Start-Up CAUTION When the heater is installed it must not be dismantled. After you have installed the heater, bleed the fuel supply system carefully. 8.7.1 Air Heater, Removal and Installation NOTE As a result of the low fuel consumption the heater must be switched on several times to fill the fuel line. 8.7.1.1 Removal 1. 2. 3. 4. 5. 6. 7. 8. 9.
Air Top 2000 S 9 Repair 9. Repair 9.1.2.1 Installation of an External Temperature Sensor 9.1 General General The heater can control the required temperature perfectly if its temperature sensor is exposed to the air of the main area of the vehicle. In certain circumstances, this is not always possible using the temperature sensor integrated in the control unit due to the installation circumstances (addition of fresh air).
9 9.2 Air Top 2000 S Repair Disassembly and Assembly 9.2.1.3 Covers for Heating Air Inlet and Outlet Both covers (3 and 6, Fig. 901) can be released and removed by pressing the four detents on top and bottom using a suitable tool. 9.2.1 Removal of Housing Components/Covers 9.2.1.1 Cover for Electrical Connection 9.2.1.4 Upper Housing Shell Dependent on the type of installation the cable loom exits the air heater either on the left or right. The cover (1, Fig.
Air Top 2000 S 9 Repair 9.2.2 Replacement of Control Unit 9.2.3 Replacement of Temperature Limiter 9.2.2.1 Removal 9.2.3.1 Removal During removal avoid the build-up of static charge (i.e. do not touch strip conductors). 1. Remove heater from vehicle (see 8.7.1.1). 2. Remove covers for heating air inlet and outlet (6 and 3, Fig. 901) according to 9.2.1.3. Remove upper housing shell according to 9.2.1.4. Disconnect terminal connections (1, Fig. 902).
9 Air Top 2000 S Repair 1 3 4 5 X6 2 7 6 1 2 3 4 5 6 7 Plug Connections Control Unit Screw (2) Screw (2) Temperature Limiter Bracket Screw Fig.
Air Top 2000 S 9 Repair 1 ! MAX. 2 1 Insulation 2 Seal Fig. 903 Replacement of Combustion Air Fan (Disassembly) 9.2.4 Replacement of Combustion Air Fan 9.2.4.1 Removal 1. 2. 3. 4. Remove air heater (see 8.7.1.1). Remove control unit (see 9.2.2.1). Remove seal (2 Fig. 903) from lower housing shell and discard. Remove air heater from lower housing shell. 5. 6. 7. 8. Remove insulation (1, Fig. 903) Remove screws (1, Fig. 904). Withdraw combustion air fan (3) and remove gasket (2).
9 Air Top 2000 S Repair 9.2.4.2 Installation 1. 2. 3. Ensure that sealing surfaces on combustion air fan and on heat exchanger are not damaged. Place new gasket (2, Fig. 904) onto flange of combustion air fan (3). Place combustion air fan into assembly position and mount using screws (1). Torque screws (1) to 6 Nm.
Air Top 2000 S 9.2.5 Replacement of Flame Sensor 9.2.5.1 Removal 1. 2. 3. 4. 5. 6. 7. 8. Remove air heater (see 8.7.1.1). Remove control unit (see 9.2.2.1). Remove combustion air fan (see 9.2.4.1). Remove screws (3, Fig. 905) and spoiler (2) for cable protection. Push out cable grommet (10) towards inside. Carefully bend up locking tab (4) and withdraw flame sensor (1) from burner insert (5). Remove flame sensor. Perform work on components after disassembly (see 9.1.1). 9.2.5.
9 Air Top 2000 S Repair 8 7 9 6 10 11 4 3 1 2 3 4 5 6 7 8 9 10 11 12 13 Flame Sensor Spoiler Screw (4) Locking Tab Burner Insert Combustion Tube Gasket Heat Exchanger Cable Grommet Cable Grommet Glow Plug Grommet Screw 5 13 2 12 1 Fig.
Air Top 2000 S 9 Repair Detail A Starting Air Bore Detail B Twist Lock Fig.
9 Repair 9.2.7 Replacement of Burner Insert, Combustion Tube, and Heat Exchanger CAUTION If the heat exchanger is going to be replaced, the temperature limiter must also be replaced. 9.2.7.1 Removal 1. 2. 3. 4. 5. Remove air heater (see 8.7.1.1). Remove control unit (see 9.2.2.1). Remove combustion air fan (see 9.2.4.1). Remove flame sensor (see 9.2.5.1). Remove glow plug (see 9.2.6.1). CAUTION When performing the following step ensure that fuel connection is not bent. 6. 7. 8.
Air Top 2000 S 10. 10 Packaging/Storage and Shipping Packaging/Storage and Shipping 10.1 General When it is necessary to ship the heater and its components to a Webasto repair center for inspection or repair, they are to be cleaned and packaged so that they are protected against damage during handling, transportation, and storage. In storage an ambient temperature of +85 °C and -40 °C must not be exceeded.
Notes Air Top 2000 S
WEBASTO PRODUCT N.A., INC. 15083 North Road Fenton, MI 48430 Technical Assistance Hotline USA: (800) 860-7866 Canada: (800) 667-8900 Org. 06/2008 Rev. N/A P/N LIT9000557A © 2008 Webasto Product N.A., Inc. www.techwebasto.com www.webasto.
