AERODYNE Heater Service Manual rev 02 Feb 2007

(C) Copyright 1994 K E N D A L L GmbH Medizinische Erzeugnisse All rights reserved

TYCO HEALTHCARE Deutschland GmbH Gewerbepark 1 D-93333 Neustadt / Donau Tel. (09445) 959-0 • Fax (09445) 959-155

All rights reserved, in particular the translation into foreign languages. The manual must not be copied in whole or in parts, neither by photocopy, microfilm, or electronic processes, nor as computer files, without prior written approval of TYCO HEALTHCARE.

Service and warranty TYCO HEALTHCARE guarantuees that after extensive quality controls this unit has been shipped in a proper state. It complies with the listed standards and regulations. Compliance with the specifications is guaranteed.

Warranty All technical information, plans, and drawings, have been made up or compiled with ultimate care and have been reproduced under efficient controls. However, errors cannot be excluded. For this reason, we state that no warranty can be taken for the correctness of the content. We appreciate any information about errors in the current manual.

Warning Any guarantee will expire when the unit will be opened by non-authorized personnel or in case that the arrangement of the device will be changed or that nonproprietary or inedequate accessories will be used.

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Safety Always disconnect mains plug before opening the unit!! Any measurements and function tests should be made using an isolating transformer. Never directly touch live parts. Always comply with safety symbols and warnings in the manual!!

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AERODYNE Heater is a device for the heating and humidification of respiratory gas. The heating temperature is permanently controlled and kept constant at the heating element. The heating intensity can be adjusted at the unit.

Features and benefits of the AERODYNE Heater Nebulization in a closed system. ■ Ensured sterility. ■ Immediate availability. ■ Easy mounting and convenient handling. ■

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Chapter Overview ■

General information - Chapter 1 gives a short introduction into the use of the AERODYNE Heater and describes how to use this manual.

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Quick start - Chapter 2 gives a short and clear description of putting into service and operation.

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Description of functions - Chapter 3 describes the functions and operational procedures of the AERODYNE Heater, thus facilitating maintenance and troubleshooting.

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Safety inspection- Chapter 4 describes the function and safety test procedures.

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Maintenance- Chapter 5 includes a service schedule, to-do lists, and information on the maintenance of operational safety.

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Troubleshooting - starting with a measuring point table, Chapter 6 guides from the identification of defects to their remedy.

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Drawings - Chapter 7 includes wiring diagram, exploded view, and a parts list of the AERODYNE Heater.

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Specifications and test protocols - Chapter 8 includes a list of the most relevant specifications and test protocols of the AERODYNE Heater.

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Table of contents Chapter 1 - General information ■ System description p.1 ■ Principle of operation p.2 ■ How to use the service manual p.3 Chapter 2 - Quick start ■ Preparations for starting-up p.4 ■ Operation p.5 ■ Precautions and safety measures p.6 Chapter 3 - Description of functions ■ Block diagram p.8 ■ Wiring p.9 ■ Operation p.11 Chapter 4 -Safety inspection ■ Visual inspection p.13 ■ Function test p.13 ■ Electrical safety p.14 ■ Safety inspection p.14 Chapter 5 - Maintenance ■ Visual inspection p.15 ■ Function test p.16 ■ Electrical safety p.17 ■ Final report p.17 ■ Maintenance and preservation of value p.17 Chapter 6 - Troubleshooting ■ Identification and analysis of defects p.18 ■ Remedies p.20 Chapter 7 - Drawings ■ Spare parts and accessories p.21 ■ Wiring diagram p.23 ■ Exploded view p.25 ■ Parts list p.26 Chapter 8 - Specifications and test protocols ■ Specifications p.27 ■ NTC probe - response curves p.30 ■ Sample test protocols p.32 ■ EC - declaration of conformity p.34 ■ Notes p.35 AERODYNE Heater tyco Neustadt

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CHAPTER 1

GENERAL INFORMATION

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System description

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Principle of operation

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How to use the service manual

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Chapter 1 • General information ■

Page 1

System description:

AERODYNE Heater is a device for the heating and humidification of respiratory gas. The patient's respiratory gas is humidified by heated nebulization (aerosol administration) together with the KENDALL sterile water systems.

The unit is composed of the following components: AERODYNE Heater. ■ Sterile packed warm nebulization adapter. ■ Bottle with sterile water according to USP. ■

At the heating pin, the temperature is permanently recorded with a temperature probe and with a compact electronic control device kept at a constant value. The required heating intensity can be continuously varied with a control knob. This closed system ensures ultimate safety and a strongly reduced contamination risk. The humidifaction system that has been proven for years. It is operated with sterile distilled water for inhalation, according to USP. The water does not contain bacteriostatic additives, thus preventing potential patient complications due to these compounds. Due to its purity, this water cannot serve as a nutrient for potential germs.

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Chapter 1 • General information ■

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Principle of operation:

Distilled water is heated via a titanium heating pin that itself is heated by a heated wire. The required heat is released into respiratory gas via the outer wall of the heating pin. The nebulization adapter works by Venturi's principle. The sterile water is aspirated from the bottle and heated in the AERODYNE Heater at the inner wall of the titanium heating pin, generating areosol particles in a 1.4 - 8 micrometer size range. The incoming respiratory gases are humidified and then supplied to the patient.

Oxygen Jet Underpressure Ascending water Oxygen concentration adjustment

Oxygen supply (bottle or wall connector)

To the patient Return flow

AERODYNE Heater for warm nebulization

RESPIFLO universal bottle

CAUTION !

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Observe documentation and manual!

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Chapter 1 • General information ■

Page 3

How to use the service manual:

The current manual has been structured and written to make maintenance and troubleshooting as convenient and efficient as possible. The order of the chapters follows the order of measures that should be taken at service. Special attention has been given to an extensive and detailed discussion of the control electronics. The section "principle of operation" discusses all parts and their function in the unit. Their knowledge is an essential basis for the fast and efficient remedy of all defects. Oscillograms and and current setpoints at all major wiring junctions help to rapidly identify defects. Routine function tests and periodic safety controls and maintenance are discussed in separate chapters. The service technician should follow these instructions and schedules as close as possible, as they will support efficient and rapid work. At the end of the manual, one page is reserved for personal notes. You should use it to enter own knowledge and information. It may help you to identify future problems. Always use original spare parts. Order numbers and all other required data are listed at the end of this manual.

■ Comply with all hints and warnings!! ■ ■ Safety for you and the patient is first priority!! ■

CAUTION !

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Observe documentation and manual!

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CHAPTER 2

QUICK START

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Preparations for starting-up

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Operation

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Precautions and safety measures

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Chapter 2 • Quick start ■

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Preparations for starting-up:

The information on starting-up is related to the identification of defects and errors. Therefore it is unneccessary in most cases to perform this procedure with the complete AERODYNE Heater unit, i.e. including sterile water. The discussion of the starting-up procedure aims at the evaluation of electrical and control parts of the AERODYNE Heater. For the test of all electrical and electronic components, the AERODYNE Heater should be connected with the mains (i.e. 230V/50Hz). Then the mains switch is switched on. The mains control lamp should be illuminated.

* Set the temperature pre-selection to the lowest possible value. * The heater should be heating now.

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Chapter 2 • Quick start ■

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Operation:

With a suitable metal adapter, the nebulization adapter can be connected to all oxygen flow meters. Assemble the heater to the wall track, then proceed as follows: 01> Take the bottle from the protective sheath and screw it into the bottom part of the AERODYNE Heater without tilting. Take care not to screw the bottle too tight. 02> Take the nebulization adapter from the packaging, and screw it tight to the AERODYNE Heater. 03> Remove the protective cap from the nebulization adapter tube, by holding the tube carefully behind the protective collar. 04> With a gentle twisting and pushing movement, insert the pin into the puncture point of the bottle. 05> Connect the nebulization adapter to the flow meter. 06> Put a 120 cm aerosol tubing piece on the nebulizer outlet and select the intended oxygen concentration. 07> Connect the heater to the mains and switch it on. 08> Adjust the flow rate to 8 L/min or at a 28% O2 concentration to 5 L/min. 09> The unit works as intended, if water flows into the reservoir via the return flow tubing. 10> Adjust the intended temperature at the heat controller. After 2 minutes, the patient is supplied with a warm aerosol. After approximately 15 minutes, the temperature is stable. The aerosol temperature depends directly from ambient temperature, flow rate, tubing length and material. The temperature of the outgoing aerosol should be permanently monitored.

CAUTION !

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Observe documentation and manual!

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Chapter 2 • Quick start ■

Page 6

Precautions:

IMPORTANT ➡ Never autoclave the AERODYNE Heater for sterilization. ➡ Never soak the AERODYNE Heater in disinfectants. ➡ Never sterilize with ethylene oxide. ➡

Always use original spare parts.

➡

Do not operate high-frequency, short wave or microwave equipment AERODYNE Heater because it might interfere with its proper operation!

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near the

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CHAPTER 3

DESCRIPTION OF FUNCTIONS

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Block diagram

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Wiring

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Operation

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Chapter 3 • Description of functions ■

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Block diagram:

The block diagram demonstrates the principles of structure and function of the AERODYNE Heater. The structuring into functional units is like the combination of U217B of TEMIC with external wiring elements. The individual blocks demonstrate the structure of the closed loop and thus the overall function. The component U217B allows direct mains (230 V / 50 Hz) voltage supply without transformer. The required supply voltage is prepared and stabilized in the internal power supply. Following half-way rectification by diode V1 and current limiting by R8, the pulsing direct current is smoothed by C3. The power supply also generates the internal 1.25 V reference voltage for comparator control. The synchronization block correctly triggers the output stage at zero crossing and switches always complete waves (composed of positive and negative half-waves -> no DC mains load at only one switched half-wave). It receives the zero crossing information of the mains voltage via resistor R9 at pin 8. At the non-inverting input of the comparator., the voltage divider branch is wired with thermistor R1. If the voltage at pin 3 is higher than the setpoint value (= pre-set temperature), the output of the comparator will be transferred. An internal pulse amplifier generates a triggering signal for triac ignition. The NTC resistor R1 that is thermally coupled with the heating wire is in the bottom branch of the voltage divider at pin 3. When temperature increases, the resistor of the NTC resistor decreases resulting in a decrease in the input voltage at the non-inverting input of the comparator. When the input voltage is lower than the value set at R5 at pin 4, the triac in the power supply is no longer triggered so that heating is switched off. When the input voltage at the inverting comparator input is lower than that at the noninverting input and and also more negative than the 1.25 V reference voltage, the output at pin 6 permanently transfers ignition pulses to the triac gate. Thus, the thermal coupling of the NTC resistor with the heater builds up a closed control loop. The functional construction of the U217B ensures safe and simple two-point control operation. The wire of the heating element can be considered as an almost ideal resistor so that inductivity considerations can be neglected. Faults due to defects of individual compounds are prevented by an overtemperature reset safeguard (response temperature = 98°C) and 2 medium time-lag overcurrent circuit breakers (2 A).

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Chapter 3 • Operation ■

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Wiring:

* Specifications of the U217B component of TEMIC: - Direct mains supply without transformer. - Current input < 0.5 mA - Full-wave control -> no DC current portion. - Typical initial pulse current = 100 mA (short circuit resistant). - Internal reference voltage generation (1.25 V). - Internal ramp generator. The component U217B enables the generation of compact control loops for temperature monitoring and control directly at 230 V mains. The 8-pole DIL housing integrates the generation of operating and reference voltage, comparison of setpoint and actual value, zerovoltage switch with complete triac ignition voltage preparation, and a ramp generator. It is used for direct mains control of heating loads (e.g. heaters). For the prevention of DC portions when power is taken up from the mains, the component switches the triac on only at mains zero crossing and only for integer multiples of the mains frequency. The ramp generator makes it possible to generate an ignition burst (reliable ignition).

* Details of the circuit: A) Power supply: The IC U217B is equipped with an internal voltage limiter and stabilizer. Therefore, the circuit can be directly supplied with 230 V mains power via a diode (V1) and a resistor (R8). Between pins 5 and 7, the internal limiter generates a voltage that is typically 9.25 V. The operating current results in a decrease in the residual voltage at R8. The power dissipation of 3 watts is intended for this decrease. The half-way rectification at V1 generates a pulsing 50 Hz DC voltage that is sieved at the electrolytic capacitor C3 that via pins 5 and 7 is fed to the control circuit.

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Chapter 3 • Operation

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B) Temperature setting and control: At both comparator inputs, the setpoint voltage is applied to pin 4 and the actual voltage to pin 3. Both branches represent a voltage divider with a varying number of variable resistors. The operator sets the temperature setpoint with potentiometer R5. The other 3 resistors limit the adjustment range (R3 and R7) or enable an exact balance (R4) of the adjustable heating temperature minimum and maximum values. Depending from the R4 settings, the voltage at pin 4 can be varied from 3.5 V (minimum) to 5.9 V (maximum). The resistor branch consisting of R2, R6, and NTC R1 generates a voltage that is proportional to the actual heating wire temperature. The temperature-dependent resistance of the NTC can be seen from the characteristic curve in chapter 8. The high resistance of R2 compared to R1 guarantees minimum intrinsic heating of the NTC preventing erroneous data. The parallel resistor R6 linearizes the NTC characteristic curve within the working temperature range. The capacitors C1 and C2 ensure stable inputs at both IC inputs.

C) Power section and load: The power section consists of heating wire (R11), triac (V2), VDR (R10), and anti-interference capacitor (C4). The triggering circuit ingnites the triac only in the first quadrant (normal plus), i.e. UA2/A1=positive and UG/A1=positive. For the elimination of power dissipation heat, the triac is equipped with a heat sink. The heating wire has an electrical power of 150 W. This refers to an operating current of ca. 680 mA. A parallel voltage-dependent resistor (R10) prevents voltage steps at the triac. Capacitor C4 serves the interference elimination of the complete power section. D) Fuses: The complete circuit has a threefold protection, including 2 fuses in both 230 V mains connections (redundancy = double safety) to protect against short circuits, and a Thermo reset fuse directly at the heater that will switch off the heater if after an electronics defect the temperature will increase above ca. 100°C.

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Chapter 3 • Operation ■

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Operation:

Construction and wiring of the AERODYNE Heater represent a closed loop with the following components: -

Controlled variable = water temperature. Actual value recording = NTC resistor. Feedback value = temperature-proportional NTC voltage. Reference input signal / setpoint = potentiometer presetting. Comparison between setpoint and actual value = comparator in IC. Actuating variable = triac ignition signal. Power amplifier = triac. Actuator = heating wire. Controlled system = water in heating tube.

Due to heat transition resistance effects and metal heat capacities (titanium heating) and water (distilled water), the designed two-point controlled system (load only ON or OFF -> no intermediate values possible) has a pronounced delay characteristics (PT1 controller). This delay in time results in a transient effect that only slowly achieves the temperature setpoint (over and under transitions). This means that the NTC registers the current water temperature with some time delay and thus also switches the heating on and off with some delay. The resulting temperature needs a transient period (ca. 20 minutes) before the temperature setpoint is achieved. A permanent control deviation is a characteristic of a two-point controlled system.

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Chapter 3 • Operation

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FAULTS: 1) Interrupted connection to NTC: The controller interprets this situation as a too small actual temperature value. As a result, the heating lowad stays permanently switched on. The same occurs when a defective triac is permanently conductive (triac short circuit). 2) NTC short circuit

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NTC low resistance = high temperature / triac switches off.

3) Poti interruption

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same effect to circuit as NTC interruption.

4) Poti short circuit

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low temperature setting = triac switches off.

5) IC U217B defective

– =

1 Signal at PIN 6 output (triac triggering) full heating efficiency - same effect as triac short circuit.

6) IC U217B defective

– =

0 Signal at PIN 6 output (triac triggering) no heating - triac not triggered.

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CHAPTER 4

SAFETY INSPECTION

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Visual inspection

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Function test

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Electrical safety

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Safety inspection

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