Webasto 2000 B, 2000S D User Manual

List of Contents

Air Top 2000

Air Heater

Air Top 2000 D (Diesel) Air Top 2000 B (Gasoline)

Service and Repair Manual

NOTE

Technical changes in this issue of the

manual compared with its previous issue

are identified with a vertical change bar on

the lefthand side of columns.

– 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.

– NEVER attempt to install or repair a Webasto heating or cooling system unless you

have successfully completed the factory training course and have the technical skills, technical information, tools and equipment required to properly complete the necessary procedures.

– ALWAYS carefully follow Webasto installation and repair instructions and heed all

WARNINGS.

– Webasto rejects any liability for problems and damage caused by the system being

installed by untrained personnel.

Air Top 2000

List of Con tents

List of Cont en ts

1. Introduction

1.1 Scope and Purpose.................................................................................................................................101

1.1.1 Use of Air Heaters...................... .......... ........ .......... .......... .......... .......... ........ .......... .......... .......... .101

1.2 Meaning of Warnings, Cautions, and Notes............................................................................................101

1.3 Additional Documentation to be used................................................................................................. .....101

1.4 Safety Information and Regulations........................................................................................................101

1.4.1 General Safety Notes......................................................................................... .........................101

1.5 Legal Provisions for Installation...................................................... ................ ................ ................ .........102

1.6 Corrections and Improvements.......... ................ ................ ................ ................ ................ ................ .....103

2. General Description

2.1 Combustion and Heating Air Fan ............................................................................................................201

2.2 Heat Exchanger.................................................................. ................ ................ ................ ................ .....202

2.3 Burner Insert with Com bustion Tube........................ .......... .......... ........ .......... .......... .......... .......... ........ ...202

2.4 Control Unit / Control Circuit Board.................. ................ ................ ................ ................ ................ .......202

2.5 Flame Sensor..........................................................................................................................................203

2.6 Glow Plug........................................................... ................................................ .....................................203

2.7 Temperature Limit er. ...... ........ .......... .......... .......... .......... ........ .......... .......... .......... .......... ........ .......... .......203

2.8 Dosing Pump...........................................................................................................................................20 3

3. Functional Description

3.1 Functional Description Air Top 2000 without Diagnosis (Fig. 301)..........................................................301

3.1.1 Control Element..........................................................................................................................301

3.1.2 Switch-On....................................................................................................................................301

3.1.3 Stabilization.................................................................................................................. .. .. .. .. .. .. .. .301

3.1.4 Heating Operation.......................................................................................................................301

3.1.5 Control Operation........................................................................................................................302

3.1.6 Control Idle..................................................................................................................................302

3.1.7 Switch-Off....................................................................................................................................302

3.1.8 Functions of the Air Heater in TRS Vehicles............................................ .......... .......... .......... .....302

3.1.9 Switch-Off upon Failure...............................................................................................................302

3.2 Functional Description Air Top 2000 Diagnosis................................................................................ .......304

3.2.1 Control Element..........................................................................................................................304

3.2.2 Switch-On....................................................................................................................................304

3.2.3 Stabilization.................................................................................................................. .. .. .. .. .. .. .. .304

3.2.4 Heating Operation.......................................................................................................................305

3.2.5 Control Operation........................................................................................................................305

3.2.6 Control Idle..................................................................................................................................305

3.2.7 Switch-Off....................................................................................................................................305

3.2.8 Functions of the Air Heater in TRS Vehicles............................................ .......... .......... .......... .....305

3.2.9 Switch-Off upon Failure...............................................................................................................306

4. Technical Data .... ........ ........ ........ ............ ........ ............ ........ ........ ............ ........ ............ ........ ........ ............ .......401

List of Contents

5. Troubleshooting

5.1 General....................................................................................................................................................501

5.2 General Failure Symptoms.................................................................................................... ..................501

5.3 Failure Symptoms during Operation........................................................................................................502

5.4 Error Code Output (Air Top 2000 Diagnosis) ............................................................ ................ ..............503

6. Functional Test s

6.1 General....................................................................................................................................................601

6.2 Adjustments................................................................................................... ..........................................601

Air Top 2000

6.2.1 Adjustment of the CO

6.3 Components Testing .. .. .. .. .. .. .... .. .. .. .. .. .. .... .. .. .. .. .. .. .... .. .. .. .. .. .. .... .. .. .. .. .. .. .... .. .. .. .. .. .. .... .. .. .. .. .. .. .... .. .. .. .........602

6.3.1 Glow Plug Resistance Test.........................................................................................................602

6.3.2 Flame Sensor Resistance Test............................... ....................................................................602

7. Circuit Diagrams

7.1 General....................................................................................................................................................701

8. Servicing

8.1 General....................................................................................................................................................801

8.2 Work on the Air Heater.......................... .......... ........ .......... .......... .......... .......... ........ .......... .......... .......... ..801

8.3 Work on the Vehicle .................................................................................................. ..............................801

8.4 Air Heater Test Run.................................................................................................................................801

8.5 Servicing..................................................................................................................................................801

8.6 Visual Inspections and Installation Regulations ......................................................................................801

8.6.1 Heating Air System ........ .......... ........ .......... .......... .......... .......... ........ .......... .......... .......... .......... ....801

8.6.2 Fuel Supply............................................................................................................. ....................802

8.6.3 Dosing Pump...............................................................................................................................804

8.6.4 Fuel Filter.......................................... .......... .......... .......... .......... ........ .......... .......... .......... .......... ..804

8.6.5 Combustion Air Supply................................................................................................................805

8.6.6 Exhaust Line ...............................................................................................................................805

8.6.7 Combustion Air Intake and Exhaust Lines..................................................................................805

8.6.8 Electrical Connections.................................................................................................................806

Contents......................... .......................................................... ..............601

8.7 Removal and Installation.........................................................................................................................808

8.7.1 Air Heater, Removal and Installation................................................... ................ ................ ........808

8.7.2 Replacement of Control Unit.......................................................................................................808

8.7.3 Replacement of Temperature Limiter..........................................................................................808

8.8 Installation of new Control Units..............................................................................................................811

8.8.1 Replacement of Control Unit Air Top 2000 (12 Volt)

with External Temperat ure Sensor............................................................ ................ ................ ..811

8.8.2 Replacement of Control Unit Air Top 2000 (24 Volt) not TRS.....................................................811

8.8.3 Replacement of Control Unit Air Top 2000 (24 Volt) TRS......................................................... ..812

8.9 First Operation.........................................................................................................................................812

Air Top 2000

9. Repair

9.1 General....................................................................................................................................................901

9.1.1 Work on Components after Disassembly....................................................................................901

9.1.2 Incorporation of Modifications.............................................................. .. .....................................901

9.2 Disassembly and Assembly.....................................................................................................................902

9.2.1 Removal of Housing Components/Covers..................................................................................902

9.2.2 Replacement of Control Unit.......................................................................................................904

9.2.3 Replacement of Temperature Limiter............................................................. ................ .............904

9.2.4 Replacement of Combustion Air Fan ..........................................................................................905

9.2.5 Replacement of Flame Sensor....................................................................................................906

9.2.6 Replacement of Glow Plug..........................................................................................................906

9.2.7 Replacement of Burner Insert, Combustion Tube, and Heat Exchanger....................................909

10. Packaging/Storage and Shipping

10.1 General..................................................................................................................................................1001

List of Con tents

III

Lis t of Figu res

Air Top 2000

Lis t of Figu res

301 Functional Diagram (Air Top 2000 without Diagnosis)....................................................................................303

501 General Failure Symptoms.............................................................................................................................501

502 Failure Symptoms during Operation...............................................................................................................502

601 Adjustment of CO

701 Terminal Pin Assignment, Air Top 2000 Diagnosis.........................................................................................701

702 Terminal Pin Assignment, Air Top 2000 without Diagnosis............................................................................702

703 Circuit Diagram Automatic Control Air Top 2000 Diagnosis, 12V/24V with Control Element.........................703

704 Circuit Diagram Automatic Control Air Top 2000 Diagnosis, 12V/24V with Combination Tim er.....................704

705 Circuit Diagram Automatic Control Air Top 2000 Diagnosis,

12V/24V with Control Elem ent and Standard Tim er........................................... ................ ................ ............705

706 Circuit Diagram Automatic Control Air Top 2000 Diagnosis,

24V TRS Operation with Control Element................................................................ ................ ................ ......706

707 Circuit Diagram Automatic Control Air Top 2000 Diagnosis,

24V TRS Operation with Combination Tim er.................................................... ................ ................ ..............707

708 Circuit Diagram Automatic Control Air Top 2000 Diagnosis,

24V TRS Operation with Combination Tim er and 2 Auxiliary Drives..............................................................708

709 Circuit Diagram Automatic Control Air Top 2000 without Diagnosis, 12V with Control Element....................709

710 Circuit Diagram Automatic Control Air Top 2000 without Diagnosis,

12V with Control Element and Timer.................................................. ................ ................ ................ ............710

711 Circuit Diagram Automatic Control Air Top 2000 without Diagnosis, 24V with Control Element....................711

712 Circuit Diagram Automatic Control Air Top 2000 without Diagnosis,

24V with Control Element and Timer.................................................. ................ ................ ................ ............712

713 Circuit Diagram Automatic Control Air Top 2000 without Diagnosis,

24V with Control Element , TRS................................................ ................ ................ ................ ................ ......713

714 Circuit Diagram Automatic Control Air Top 2000 Diagnosis,

24V TRS Operation with Control Element in Vehicles without Auxiliary Drive................................................714

715 Connection Diagram, Air Top 2000 Diagnosis with Combination Timer (not TRS!).............................. ..........715

Contents ..........................................................................................................................601

801 Fuel Supply.....................................................................................................................................................802

802 Webasto Fuel Tank Tap ................................................................................................................................. 803

803 Fuel Tapping from Plastic Tank (tapping via fuel drain plug).................................................. ................ ........803

804 Fuel Tapping from Plastic Tank (tapping via fitting plate)......................................................................... ......803

805 Pipe/Hose Connection....................................................................................................................................804

806 Dosing Pumpe, Installation Position and Attachment....................................................................... ..............804

807 Fuel Filter................................................................ ................................................ .. ......................................804

808 Exhaust Muffler, Direction of Flow..................................................................................................................805

809 Exhaust Pipe Outlet, Installation Position..................................... ................ ................ ................ ................ ..805

810 Removal of Fuse Holder Attachment Plate.....................................................................................................806

811 Fuse Holder, Installation Position ........................................... ................ ................ ................ ................ ........806

812 Control Element..............................................................................................................................................806

813 Pulling the Plug...............................................................................................................................................806

814 Example of an Installation...............................................................................................................................807

815 Replacement of Control Unit and Temperature Limiter (Air Top 2000 without Diagnosis).............................809

816 Replacement of Control Unit and Temperature Limiter (Air Top 2000 Diagnosis)..........................................810

901 Removal of Housing Components/Covers......................................................................................................903

902 Replacement of Combustion Air Fan (Removal) ............................................................................................904

903 Replacement of Combustion Air Fan (Disassembly)......................................................................................905

904 Disassembly of Heat Exchanger........................................................................................................... ..........907

Air Top 2000

1 Introduction

1. Introduction

1.1 Scope and Purpose

This repair shop manual is intended to support familiarized personnel in the repair of air heaters Air Top 2000 of the fuel and Diesel type as well as of Air Top 2000 Diagnosis with serial no. 30.000 and up.

1.1.1 Use of Air Heaters

The air heaters Air Top 2000 and Air Top 2000 Diagnosis are used to

- heat the cabin

- defrost the windscreens. They are not cleared for heating a transportation com-

partment for dangerous goods. The heaters operate independent from the vehicle engine and are connected to the fuel tank and to the electrical system of the vehicle. Their use is possible in vehicles with water- or air-cooled engines.

1.2 Meaning of Warnings, Cautions and Notes

WARNINGS, CAUTIONS, and NOTES in this manual have the following meaning:

WARNING

This heading is used to highlight that non-compliance with instructions or procedures m ay cause injuries or lethal accidents to personnel.

CAUTI ON

This heading is used to highlight that non-compliance with instruct ions or procedures m ay cause dam age to equipment.

NOTE

This heading is used to highlight and draw specific attention to information.

1.3 Additional Documentation to be used

This workshop manual contains all informat ion and procedures necessary for the repair of heaters Air Top 2000 and Air Top 2000 Diagnosis. The use of additional documentation is normally not necessary. Operating instructions/ins tallat ion instruct ions and the vehicle specific installation proposal may be used as complementary inform ation as necessary .

1.4 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.The specific safety regulations applicable to this manual are highlight ed in the individual chapters by Warnings, Cautions, and Notes.

1.4.1 General Safety Notes

Within the scope of the StVZO (Road Licensing Regulations of the Federal Republic of Germany) “Design General Approvals”, laid down by the Federal Office for Motor Traffic, exist for the Water Heater Air Top 2000 and Air Top 2000 Diagnosis with the following official marks of conformity:

-S 270 (Diesel)

-S 277 (Fuel)

The installation of the heaters is to be performed in accordance with the installation instruct ions and must be checked in case of a) the vehicle type inspection in accordance with

§ 20 StVZO

b) the individual inspection in accordance with

§ 21 StVZO or

c) the examination in accordance with § 19 StVZO

performed by an officially authorised expert or examiner for road traffic, a vehicle inspector or a public servant as per section 7.4 a of Annex VIII to the

StVZO. In the event of c) the installation must be certified on the acceptance certificate included in the copy of the “General Operating License” giving details about

- manufacturer

- ty pe of vehicle , and

- vehicle identif ication num ber. This validates the “Design General Approval”.

The acceptance certi ficate must be kept with the vehicle. The year of first operation must be permanently marked on the identification label.

The heaters are cleared for heating the passenger and driver cabins but not for heating compartments intended for the transportation of dangerous goods. The use of the heater in special vehicles (e.g. vehicles for the transportation of dangerous goods TRS) or vehicles not subject to the StZVO (e.g. ships) are ruled by partially regional regulations. For the installation of the the transportation of dangerous goods, in addition to the StVZO, the requirements in TRS 002 and TRS 003 (Technical Guidelines for the Transportation of Dangerous Goods on Roads) must be met.

AT 2000 D in vehicles used for

101

1 Introduction

Air Top 2000

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 station s and fuel depots the heat er mu st be switched off as there is a potenti al dan ger of exp losion.

Where flammable fumes or dust may build up (e.g. in the vicini ty of fuel, coal , wood, cereal depots, or similar installat ions) the heat er must be switched off to prevent explosions.

Due to the danger of poisoning and suffocation the heater must not be operated in enclosed areas such as garages or workshops without exhaust venting, not even if the start-up is activated by the timer or telest art device.

When removing the heater the gasket below must be replaced.

The heat exchanger of the air heater remains serviceable for a maximum of 10 years and must then be r eplaced with an original spare part by the manufacturer or by one of its authorized workshops. The heater must then be provided with a label marked with the sales date and with the words “Original Spare”. Should exhaust pipes be rou ted through room s accommodating person s, these pipes shal l also be renewed after 10 years.

Heating Air System

Heating air intake openings must be arranged so that under normal operating conditions exhaust fumes of the vehicle engine or air heater are not likely to be expected.

Extracting combustion air from the vehicle interior is not permissible.

Combustion A ir Line

The combustion air required must be taken from the exterior. Within rooms accommodat ing persons, the com busti on air lines must not have more than four disconnects and a splash-water protected ext erior w all feedthrough. The disconnects must be sealed in a way not to exceed a leak rate of 200 l/h at an overpressure of 0.5 mbar. The line including feedthrough, disconnects, material and specific type must be described in the installation instructions. The line must require tools for installation and removal, must be protected against damage, and must be shockproof.

Exhaust Line

Heaters must be designed to discharge the exhaust to the exterior.

Exhaust pipes must be routed so that exhaust fumes are unlikely to penetrate into the vehicle’s interior. The function of any parts of the vehicle essential for its operation must not be impaired. Condensate or water penetrated must not be able to accumulate in the exhaust line. Drain holes are permissible; these must drain the fluid to the exterior via lines sealed against the vehicle interior.

Installations not legally authorized will void the air heater’s “Official Marks of Conformity” and thus the vehicle’s permit of operation. The same applies for repairs performed by unskilled personnel and repairs with no original spare parts.

1.5 Legal Provisions for Installation

For testing the heater in accordance with 19, 20, or 21 of the StVZO the following regulations are to be observed in particular (§ 22 a StVZO):

Testing is performed upon presentation of the operating and installation instructions of the manufacturer.

The year of the initial operation must be durably marked on the heater identification plate by the installing person.

The exhaust line outlet is to be positioned to the top, to the side, or in case of exhaust venting below the vehicle floor, to the nearest possible location of the vehicle’s or cockpit’s side or rear end. In compartments accommodating persons, exhaust lines must not have more th an one disconnect and must have a splash-water protected feedthrough in the exterior wall/floor . For water , that has penetrated into the exhaust line, the connection of a drain line with a metal-sealing joint is permissible. The drain pipe must be routed sealed through the exterior wall or the vehicle floor.The heat exchanger, the exhaus t line connected, as well as the possible drain pipe must be sealed so that with an overpressure of double the overpressure of the exhaust having the maximum permissible exhaust line length - at least however at an overpressure of 0.5 bar - a total leak rate of 30 l/h is not exceeded.

The line including feedthrough, disconnects, material and specific type must be described in the installation instructions. The line must require tools for installation and removal, must be protected against damage, and must be shockproof.

102

Air Top 2000

1 Introduction

Metal lines must be used. These m ay not heat to m ore than 110 °C should there be the possibility of contact within the room interior. Protective devices against contact may be fitt ed. Should exhaust pipes be routed through rooms accommodating persons, these pipes shall be renewed after 10 years using genuine spare parts.

Combustion Air Inlet and Exhaust Outlet

During installations these ports for combustion air entry and exhaust fume exit must be of such type, that a ball with a diameter of 16 mm cannot be inserted.Elec tric al lines, switch gear and control gear of the heater must be located in the vehicle so that their proper function cannot be impaired under normal operating conditions.

For the routing of fuel lines and the installation of additional fuel tanks §§ 45 and 46 of the StVZO are to be adhered to. The most important regulations are: Fuel lines are to be designed in such a way that they remain unaffected by torsional stresses in the vehicle, engine movement and the like. They must be protected against mechanical damage. Fuel-carrying parts are to be protected against excessive heat and are to be arranged so that any dripping or evaporating fuel can neither accumulate nor be ignited by hot c omponents or electrical equipment. In busses, fuel lines and fuel tanks may be located neither in the passenger area nor in the driver’s compartment. In these type of vehicles the fuel tanks must be located such that they do not pose a direct hazard to the exits in the event of a fire. Fuel supply must not be by means of gravity or pressurization of the fuel tank.

1.6 Corrections and Improvements

Deficiencies, improvements , or proposals for correction of this workshop manual are to be mailed to:

Webasto Thermosys tem e Gmb H Abt. Technische Dokumentation D-82131 Stockdorf

Telephone: 0 89 / 8 57 94 - 5 42 Telefax: 0 89 / 8 57 64 10

Installat ion Rules for Webasto Fuel Tanks for the Fuel Supply of Heaters in Vehicles

In busses the installation is not permitted in the passenger or driver compartment. The fuel fill neck must in no vehicle be located within any of these compartments. Fuel containers for carburettor fuel must not be located immediately behind the front panelling of the vehicle. They must be sparate from the engine so that even in case of an accident the inflammation of fuel is unlikely to be expected. This does not apply for towing vehicles with an open cockpit. The operational state of the heater, i.e. an indication “on” or “off”, must be easily and clearly visible.

103

Air Top 2000

2 General Description

2. General Description

The air heater Air Top 2000 and Air Top 2000 Diagnosis with serial no. 30.000 and up operating to the evaporator principle basically consist of:

- combustion and heating air fan

- heat exchanger

- burner insert with combustion tube

- control unit

A malfunction in air heaters Air Top 2000 Diagnosis outputs an error code to the display of the combination or standard timer. When equipped with a control element the operating indicator flashes. In addition a heater checkout may be performed using a personal computer (refer to operating instructions PC air heater diagnosis).

Air Heater Air Top 2000 Diagnosis

(covers removed)

Air Heater Air Top 2000

For control and monitoring a

- control unit/control circuit board

- flame sensor

- glow plug

- temperature limiter

- temperature sensor are located within the unit. 12 Volt heaters (Air Top 2000 without Diagnosis) may be

controlled by means of an external temperatur e sensor. All heaters of air Top 2000 Diagnosis may be controlled by means of an external temperature sensor.

Fuel supply is provided externally by a fuel dosing pump.

2.1 Combustion and Heating Air Fan

The combustion and heating air fan delivers the air required for combustion from the combustion air inlet to the burner insert. By means of the fan the heating air is also delivered to the air outlet.

Combustion and Heating Air Fan

Air Heater Air Top 2000 without Diagnosis

(covers removed)

201

2 General Description

Air Top 2000

2.2 Heat Exchanger

The heat exchanger dissipates the heat provided by combustion to the air delivered by the combustion and heating air fan.

Heat Exchanger

2.3 Burner Insert with Combustion Tube

Within the burner insert fuel is distributed in the combustion tube across the burner cross-section. In the combu stion tube the combustion of the fuel/air mix ture tak es place heating up the heat exchanger.

2.4 Control Unit / Control Circuit Board

Air Top 2000 without Diagnosis

The control unit /cont rol ci rc uit boar d is the central co nt rolling unit for functional sequen cing and m on itori ng of the combustion oper ation . A tempera ture sens or locate d on the side is used for temperatur e control . 12 Volt heate rs may have the temperat ure sensor replaced agai nst an external temper at ure sensor . The com bust ion an d heat in g air fan may be set by m eans of a po te nt iom eter .

Potentiometer

Temperature Sensor

Control Unit Air Top 2000 without Diagnosis

Diesel 2 mm

Combustion Tube

Burner Insert

Air Top 2000 Diagnosis

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. All heaters may have the temperature sensor replaced against an external temperature sensor. The combustion and heating air fan may be set by means of a potentiometer.

A malfunction in air heaters Air Top 2000 Diagnosis outputs an error code to the display of the combination or standard timer. When equipped with a control element the operating indicator flashes. In addition a heater checkout may be performed using a personal computer (refe r to operating instructions PC air heater diagnosis).

Fuel 1 mm

202

Air Top 2000

2 General Description

Potentiometer

Temperature Sensor

Control Unit Air Top 2000 Diagnosis

2.5 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 protec ts the air heater against excessive operating temperatures . Overheat protec tion is activated at temperature higher than 150 °C to interrupt the electrical circuit of the dosing pump and switch off the heater with run-dow n operation. After cooling down the electrical circuit is restored. The air heater may be switched on again (see 3.9).

Temperature Limiter

2.8 Dosing Pump

The dosing pump is a combined supply, dosing and shutoff system for the fuel supply of the heater out of the vehicle’s fuel tank.

Flame Sensor

2.6 Glow Plug

The glow plug ignites the fuel/air mixture at the start of the air heater operation. The glow plug is acting as an electrical resistor and is located in the burner insert opposed to the flame side.

Glow Plug

Dosing Pump DP 2 for Fuel and Diesel operated Heaters

Dosing Pump DP 30 for Diesel operated Heaters

203

Air Top 2000

3 Functional Description

3. Functional Description

3.1 Functional Description Air Top 2000 without Diagnosis (Fig. 301)

3.1.1 Control Element

The control element is used to switch the air heater on and off, set the desired room temperat ure (air intake tem perature 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).

NOTE

After application of power upon swit ch-on of the battery switch and selecting the contr ol element “ON”, the c ontrol unit enters the “error lockout” condition. Prior to a reactivation the control element has to be placed to “OFF”.

3.1.2 Switch-On

The control element is set to the desired room temperature. When switching the air heater on, the operating indicator is illuminated and the glow plug is activated (cycled). The motor of the combustion and heating air fan starts high-speed operation for 1 second (breakaway mom ent) and is then under slow-dow n control.

NOTE

Should the temperature of the intake air be above the selected, rated temperature, only the mot or of the combustion and heating air fan will operate (control idle). Start operation will be initiated with a heating air temperature below the rated temperature.

After approx. 20 seconds (for fuel operated heaters after approx. 15 seconds) the fuel dosing pump is activated. After another 25 seconds the speed of the combustion and heating air fan is continuously increased to a higher rate and combustion begins. As soon as a flame is detected, combustion w ill be stabilized (see 3.1.3) .

Should no normal combustion be achieved within 120 seconds (for fuel operated heaters after approx. 115 seconds), the speed of the combustion and heating air fan is increased for approx. 30 sec and there will be an automatic repeat start with the glow plug activated and fuel dosing pump deactivated (no fuel supply).

Should the no-combustion-condition persist , after another 80 seconds (for fuel operated heaters after approx. 85 seconds) there will be a switch-off by error lockout (see 3.1.9) with a run-down of the combustion and heating air fan lasting 120 seconds at 2/3 of its max. speed.

3.1.3 Stabili zation

Diesel Operated Heaters

With the glow plug activated the operating speed of the combustion and heating air fan is increased. After another 20 seconds the speed of the combustion and heating air fan is continuously increased within 17 seconds to full load for full heat. A flame-out during the speed rise control period causes a repeat start.

Fuel Operated Heaters

With the glow plug activated the operating speed of the combustion and heating air fan is continuously increased within 4 seconds to full load for full heat. A flame-out during the speed rise control period causes a repeat start.

3.1.4 Heating Ope ra tion

During operation the combustion exhaust gasses flow through the heat exchanger charging its walls w ith com bustion heat, which in turn is taken up by the heating air delivered by the heating air fan to be routed to the vehicle interior. The temperature of the heating air sucked in is measured by means of a temperature sensor fitt ed to the air intake side of the air heater or in case of 12 Volt heaters also by means of an externally located temperature sensor. A temperature below the one set with the control element increases the heater performanc e up to maximum heat. In order to extend the burner idle period of Diesel operated heaters during permanent operation with a heating performance in excess of 1.2 kW, the fuel dosing pump delivery rate is reduced every 30 minutes for 20 seconds.

A heating performance less than 1.2 kW causes the fuel delivery to the dosing pump to be interrupted every 30 minutes for 4 seconds. For both types of heaters (fuel and Diesel) heating operation is shortly interrupted every 9 hours like in control idle.

NOTE

The control unit/air heater reacts to new sett ings of the control element with a time delay.

301

3 Functional Description

Air Top 2000

3.1.5 Control Operation

During control operation fan speed and dosing pum p rate of delivery are subject to heating performance. The glow plug is deactivated.

3.1.6 Control Idle

In case the air intake temperature set with the cont rol element is exceeded and the minimum heating performance had been achieved for longer than 5 seconds, the fuel supply is cut off to terminate combustion. The motor of the combustion and heating air fan continues operation for another 155 seconds at 2/3 of maximum speed to cool down the air heater (run-dow n). In control idle the combustion and heating air fan runs at minimum speed. The operation indication remains lit. After reaching the air intake temperature set with the control element a new start procedure is launched (without break-away) .

3.1.7 Switch-Off

Switching the heater off ext inguishes the operation indication of the control element. If no fuel has been delivered (within 20 seconds for Diesel operated heaters or within 15 seconds for fuel operated heaters after swit ch-on) or if the air heater is in control idle, the air heater is deactivated immediately without run-down.

If fuel supply has commenced it will be immediately stopped at switch-off. The fan speed decreases within 35 seconds to 2/3 of maximum. Subsequently or if the flame sensor detects “no flame” the fan speed is increased to maximum for 60 seconds and run-down is initiated to last 120 seconds. Run-down is automatically halted.

NOTE

Re-activation of the heater during run-down is permitted. Run-down will be completed first with a subsequent restart.

3.1.8 Functions o f the A ir Hea ter in TRS Vehicles

NOTE

Applicable only for Air Top 2000 D Air Heaters installed in vehicles for the transportation of dangerous goods (TRS).

If the heater is deact ivated using the control element, run-down will not change.

A short run-down (max. 40 seconds) is automatically activated if:

the vehicle engine is turned off

a conveyor facility is put into operation

The short run-down time depends on the operational condition at which TRS swit ch-off occurs. A 40 second run-down with maxim um speed is initiate d (TRS switch-off) when:

air heater is s till in the start phase; stabilization not yet achieved

air heater is in normal run-down

air heater is in control idle.

A 20 second run-down is switched on in normal combustion operation with the fuel delivery immediately halted maintaining the fan speed for 5 seconds. Then the speed is increased for 30 seconds within another 5 seconds.

For all heaters after July 1995 the short run-down out of all operating conditions is a max. of 20 seconds.

After a TRS switch-off the control unit is in the “error lockout” condition. Prior to resuming operation the control element has to be set to “OFF”.

3.1.9 Switch-off upon Failure

The control unit recognises failures of individual air heater components and malfunctions in the start sequence and in normal operation.

The air heater is deactivated and enters the error lockout mode under the following conditions:

flame sensor resistance out of tolerance

temperature sensor resistance out of tolerance

glow plug/glow plug trigger defective

fan speed too low , short circuit or open circuit

error in dosing pump electrical circuit or of overheat protection (in start phase only)

low voltage below 10 Volt and in excess of 20 seconds for 12 Volt heaters

low voltage below 20 Volt and in excess of 20 seconds for 24 Volt heaters

control unit defective

In case of overheating there will be no fuel supply. A rundown like after manual switch-off will be performed. After run-down the control unit is in the error lockout mode. Overheating is indicated by the operation indication flashing. For error unlock the air heater has to be switched off momentarily to be switched on again.

302

Air Top 2000

3 Functional Description

3 4

On 1 0

1 2

5 6 7 8

1 0

100% 90% 60% 30% 0

1,3 Hz 1,0 Hz 0,8 Hz 0,6 Hz 0

1 0

020

65 85 102

Fig. 301 Functional Diagram (Air Top 2000 without Diagnosis)

1 Start 2 Control Operation 3 Rated Value reached 4 Rated Value exceeded

(e.g. due to reduced heat sumption) 5 Run-down 6 Control Idle 7 Start 8 Control Operation (increased heat consumption) 9 Switch-off

(20) (60)

(120)

secondstypical

A = Control Element B = Temperature Sensor C = Glow Plug D = Combustion and Heating Air Fan E = Dosing Pump F = Flame Sensor

10 Run-down

303

3 Functional Description

Air Top 2000

3.2 Functional Description Air Top 2000 Diagnosis

3.2.1 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).

NOTE

TRS Operation:

After application of power upon switch-on of the battery switch and selecting the control element “ON” , the control unit enters the “error lockout” condition. Prior to a reactivation the control element has to be placed to “OFF”.

3.2.2 Switch-On

NOTE

The flame sensor function is checked. If the flame sensor at this time already signals “flame”, there will be a 120 second run-down and an error lockout of the control unit. A malfunction of any other component monitored causes an error lockout without run-down.

Should no proper combustion develop within 120 seconds (for fuel-operated within 115 seconds) the combustion and heating air fan speed is increased to full load for approx. 30 seconds (15 seconds for fuel-operated heaters) with the glow plug on and the dosing pump off (no fuel delivery) with a subsequent automatic restart.

Should the no-combustion-condition persist, after another 80 seconds (for fuel operated heaters after approx. 85 seconds) there will be a switch-off by error lockout (see 3.2.9) with a run-do w n of the combustion and heating air fan lasting 120 seconds at 2/3 of its max. speed.

2. Start (automatic restart)

Fan speed is again reduced to approx. 30% (for fuel operated heaters to approx. 50%) and fuel is delivered. During the next 20 seconds fan speed is increased to approx. 60% (for fuel-operated heaters to approx. 75% ) of full speed. As soon as a flame is detected within the next 55 seconds, combustion will be stabilized. Should there be no flame condition after a total fuel delivery period of 180 seconds, fuel delivery will be stopped and the glow plug deactivated. The combustion air fan continues full load operation for another 120 seconds (run-dow n) and the heater enters the error lockout condition.

3.2.3 Stabilization

Diesel Operated Heaters

NOTE

This operating condition is omitted if the set temperature (control idle) has already been achieved once. The glow plug is deactivated and heating operation commences. A flame-out during speed up control causes a restart, 5 restarts an error lockout of the heater.

Fuel Operated Heaters

With the glow plug activated the operating speed of the combustion and heating air fan is continuously increased within 4 seconds to full load for full heat. This operating condition will be omitted if the start occurs after a control idle period. The glow plug is deactivated and heating operation commences. A flame-out during speed up control causes a restart, 5 restarts an error lockout of the heater.

Should no normal combustion be achieved within 120 seconds (for fuel operated heaters after approx. 115 seconds), the speed of the combustion and heating air fan is increased for approx. 30 sec and there will be an automatic repeat start w ith the glow plug activated a nd fuel dosing pump deactivated (no fuel supply).

304

Air Top 2000

3 Functional Description

3.2.4 Heating Operation

During operation the combustion exhaust gasses flow through the heat exchanger charging its walls with com bustion heat, which in turn is taken up by the heating air delivered by the heating air fan to be routed to the vehicle interior. The temperature of the heating air sucked in is measured by means of a temperature sensor fit ted to the air intake side of the air heater or by means of an externally located temperature sensor. A temperature below the one set with the control element increases the heater performance up to max imum heat. In order to extend the burner idle period of Diesel operated heaters during permanent operation w ith a heating performance in excess of 1.1 kW, the fuel dosing pump delivery rate is reduced every 15 minutes for 20 seconds.

A heating performance less than 1.1 kW causes the fuel delivery to the dosing pump to be interrupted every 30 minutes for 4 seconds. Additionaly heating operation is briefly suspended every 9 hours like in control idle. For Diesel-operated heaters this is only applicable, if at this time heating performance is less than 1.1 kW.

3.2.7 Switch-Off

Switching the heater off ext inguishes the operation indication of the control element. If no fuel has been delivered or if the air heater is in control idle, the air heater is deactivated immediately without run-down.

If fuel supply has commenced it will be immediately stopped at switch-off. Fan speed remains constant and then decreases within 30 seconds to approx. 60% of full speed. After this or with the flame sensor detect ing “no flame”, fan speed rises to maximum speed for 60 seconds and run down for 120 seconds is initiated. Rundown is at approx. 60% of full speed and is deactivated automatically.

NOTE

Re-activation of the heater during run-down is permitted. Run-down will be completed first with a subsequent restart.

3.2.8 Functions o f the A ir Hea ter in TRS Vehicles

3.2.5 Control Operation

During control operation fan speed and dosing pump rate of delivery are subject to heating performance. The glow plug is deactivated.

3.2.6 Control Idle

After reaching the temperature set w ith the cont rol element, heating performance is controlled to decrease. The speed of the combustion and heating air fan slows down and the fuel delivery rate to the dosing pump is reduced. When exceeding the air intake temperature set with the control element during minimum heating perfor mance, the dosing pump is deactivated after 5 seconds and combustion terminates. Fan speed remains constant for 35 seconds and is then increased to approx. 60% of full speed for cooling the heater down. the fan then continues to operate at approx. 30% of full speed until temperature is below the temperature set with the control element . If temperature falls below the one set with the control element, the heater will restart (wit hout break a w ay).

NOTE

New settings on the control element are executed by the control unit/heater w ith a time delay.

NOTE

Applicable only for Air Top 2000 D Air Heaters installed in vehicles for the transportation of dangerous goods (TRS).

If the heater is deact ivated using the control element, run-down will not change. A short run-down (max . 20 seconds) is automatic ally activated if:

the vehicle engine is turned off

a conveyor facility is put into operation

The short run-down time depends on the operational condition at which TRS switch-off occurs. A 15 second run-down with m aximum speed is initiated (TRS switch-off) when:

air heater is still in the start phase; stabilization not yet achieved

air heater is in normal run-down

air heater is in control idle.

A 20 second run-down is switched on in normal combustion operation and in stabilization with the fuel delivery immediately halted maintaining the fan speed for 5 seconds. Then the speed is increased to maximum for 15 seconds within for a run-down.

After a TRS switch-off the contr ol unit is in the “error lockout” condition. Prior to resuming operation the control element has to be set to “OFF”.

305

3 Functional Description

3.2.9 Switch-off upon Failure

The control unit recognises failures of individual air heater components and malfunctions in the start sequence and in normal operation.

The air heater is deactivated and enters the error lockout mode under the following conditions:

flame sensor open or short circuit

temperature sensor open or short circuit

glow plug open or short circuit

fan motor open or short circuit or fan speed wrong

dosing pump open or short circuit

overheating

low voltage below 10 Volt or high voltage above 15 Volt in excess of 20 seconds for 12 Volt heaters

low voltage below 20 Volt or high voltage above 30 Volt in excess of 20 seconds for 24 Volt heaters

A switch-off like in “sw itch- off” w ill be performed. In case of overheating there will be no fuel supply. After run-down the control unit is in the error lockout mode. The operation indication outputs a flash code. For error unlock the air heater has to be switched off momentarily (at least 2 seconds) to be switched on

Air Top 2000

306

Air Top 2000

4 Technical Data

4. Technical Data

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.

Air Heater Operation

Mark of conformity

Heater type

Heat flow

Type of fuel

Control range

Electrical Components:

Control unit, combustion air fan, dosing pump, timer*, glow plug and control element are for 12 or 24 Volts operation.

The components temperature limiter and flame detec tor are independent of voltage.

*not for TRS

AT 2000 B

~ S 277

Air heater with

evaporator burner

1.1 – 2.0 kW

Fuel

AT 2000 D

~ S 270

0.9 – 2.0 kW

Diesel/Fuel oil (EL)

Fuel consumption

Nominal voltage

Operation voltage

Rated power consumption

Permitted ambient temp.: Heater:

Dosing pump: Control element:

- operation

- storage

- operation

- storage

- operation

- storage

Permitted combustion air intake temperature

Setting range for indoor temperature

Volume flow of heating air against 0.5 bar

in exhaust

(perm. functional range)

Control range

Max.

0.1 .. 0.2 kg/h (0.16..0.27 l/h)

12 Volt

10 … 15 Volt

-40 ° … +40 °C

-40 ° … +85 °C

-40 ° … +20 °C

-40 ° … +85 °C

-40 ° … +75 °C

-40 ° … +85 °C

-40 ... +20 °C

+10 ... +45 °C

9.5 … 10.5

0.1 .. 0.21 kg/h (0.12 .. 0.24 l/h)

12 Volt

10 … 15 Volt

9 ...22 W

70 m

9.5 … 12.0

24 Volt

20 … 30 Volt

Dimensions air heater

Weight, heater

Length 322 ± 2 mm

Width 130 ± 1 mm

Height 122 ± 1 mm

2.6 kg

401

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