Cocoon CWS 4000 User manual

COCOON
Essential care before, during and after surgery.
Convective Warming Machine
CE
Model CWS 4000
SERVICE MANUAL
Distributed by
CARE ESSENTIALS PTY LTD National
Unit 62, 170 Forster Road Phone [phone]
Me Waverley Vic 3149 Australia Fax [phone]
Email queries@careessentials com.au
Web www.careessentials comau
TM
PS
International
Phone [phone] Designed &
Fax [phone] manufactured
in Australia.
Copyright © 2003 Care Essentials Pty Lid

CONTENTS
IN O O ーー 2
2. OPERATION. нина нина 4
21. UnitSetup.......... νν νο ντ νο νο νε ντε τ εεττ ο ο εκτ κκωκκκεν εεττ τετ κκκωννωνν εεττ τετ ετεκ κκ κκν τε κε εεττ ετεκ κε κας 4
2.2、 Getting Stared nm eneret esserne 5
2.3. Unit Operation Procedure 00000 eee nenene nene 5
24 Symbols ON 6
3. SAFETY PRÉCAUTIONS iii KKK 7
A κκεεεεκκκας 7
3.2. Warmnnd 8. 7
3.3. Caution................................................. 111 en 7
34. Electromagnetic Interference.......................... ener 7
4. PREVENTATIVE MAINTENANCE eee eee nenene nenene 8
O eee eee ee nene ee K K K K AA K KA KA P P nene nné 8
4.2. Electrical Safety Inspection eee ekk k 8
4.3. Performance Inspection 111111 ининининнни 9
4.4. Temperature Limit Thermostat Test Procedure …............................................ 10
4.5. Filter Replacement iii лиинннни 12
5. TROUBLESHOOTING… せ κτ εεττ ετεκ κκ κος 13
5.1. Warming Blanket Will Not Inflate irei 13
5.2. Standby Indicator Will Not Light нии nm... 13
53. EguipmentRepairs.............................................. ee 13
6. SCHEMATIC DIAGRAM DESCRIPTION ινε нии ини 13
6.1. Control Boargd R RKK KE KAP ae nn nn 14
6.2. Sensor Board νε εντ ετων ωνκκεε εεττ λε εντ τε κε ενεωκκκεεκκεεεεεε εεττ εκ κκκκκ κε ε τε εκ κκαν 15
6.3... System Block Diagram................. m. 15
7. BOARD COMPONENT LEGENDS .Nt 16
7.1. Control Board... KG Rana nn hh hn 16
7.2. Sensor Board eee 17
8. SCHEMATIC DIAGRAMS ue 18
8.1. Control Board Schematic Diagram … せ … せ … せ ーー トーーーーーーーーーーーーー 18
8.2. Sensor Board Schenmatic Diagram .................... 19
8.3. System Block Diagram i 20
INC li 21
9.1. General Assembly e eee eh reeeen nn nn 21
9.2. Control Board... 22
9.3. Sensor Board........................... ee 23
10. WARRANTY EEE EEE KEE HHK H K KKK KEE 23
11. SPECIFICATIONS............................................ nr ero rcncnncoinnnnos 24
12. APPROVALS нии 25

Care Essentials CWS4000 Cocoon Warming System Service Manual
1. INTRODUCTION
It is a pre-requisite for all persons skilled in servicing medical devices to understand the
information contained in this Manual. Read and understand this Manual and the Operator
Manual and all precautions prior to servicing the Cocoon Convective Warming System.
When used with Care Essentials patient warming blankets, the Care Essentials CWS4000
provides a continuous method of warming patients and is intended for preventing and treating
hypothermia. The Cocoon Convective Warming System consists of a CWS4000 and a warming
blanket. A connecting hose conducts heated air from the CWS4000 to the warming blanket.
Figure 1 Convective Warming System
Care Essentials recommend that a program of regular routine maintenance, electrical safety
and performance inspections be instituted for the CWS4000 as described in Section 4 below.
The CWS4000 is a mains-powered, microprocessor-controlled device that delivers a continuous
flow of temperature-controlled air through a flexible hose to the warming blanket. The
temperature of the air delivered to the blanket can be set to one of six settings: ambient, 34°C,
37°C, 40°C, 43°C, or 46°C. When a temperature of 46°C is selected, the setting automatically
drops to 43°C after 10 minutes. The CWS4000 will not cool the air delivered to the blanket
below the ambient temperature of the room.
Air is drawn into the rear of the CWS4000 and passes through a bacteriological HEPA filter. The
CWS4000 includes a number of under- and over-temperature prevention systems and in a
temperature fault condition it automatically shuts down and signals an alarm.
This Manual presents all the relevant service information for the Care Essentials CWS4000
Cocoon Warming System. This information is provided as a service to engineering and technical
personnel. This information is intended for the fair purposes of operation and maintenance of
the CWS4000. It is provided as Commercial-In-Confidence material to the Care Essentials
Distributor or CWS4000 owner and shall not be made available to any other organization or
person without the specific written permission of Care Essentials.
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Care Essentials CWS4000 Cocoon Warming System Service Manual
While every attempt has been made to ensure this Manual is accurate and complete, no
responsibility is taken for any errors or omissions. Care Essentials has a policy of continuous
product improvement and product specifications and component types are subject to change
without notice.
If you, as a user of this manual, have any relevant comments or questions about the CWS4000
or this Manual, your communication with Care Essentials would be welcomed. Our contact
details are located on the first page of this Manual.
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Care Essentials CWS4000 Cocoon Warming System Service Manual
2. OPERATION
2.1. Unit Setup
The CWS4000 may be placed on the floor, mounted on the foot of the bed using the foldout
brackets, or clamped to an IV pole using the IV pole clamp. When using an IV pole, do not
mount the CWS4000 higher than 1 metre or it could tip over. Do not place the CWS4000 ona
bed surface. Note that if the CWS4000 is placed on the floor, increased levels of dust and lint
could reduce filter life.
IV Pole Clamp
maximum
Figure 4 Pole mounting height limit
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Care Essentials CWS4000 Cocoon Warming System Service Manual
F
Output Temperature
Seiection Indicators
|
Symbols
See section 2.4
Fault Alarm Indicator
Standby Indicator Filter Status Indicator
A+
Standby Button
Output temperature
Ambient Temperature
selection buttons
Output Button
Ambient Temperature
Output Indicator
Figure 5 Operator control panel
2.2. Getting Started
Plug the mains cable into a conventional, properly earthed 240 Volt 10 Amp mains power
socket-outlet and switch it on. The green Standby indicator (B) will illuminate and the
CWS4000 will beep when power is connected.
Ensure that air is not prevented from entering the inlet slots at the sides by blankets or other
objects.
Remove the warming blanket from its packaging. Unfold the warming blanket and place it over
the patient. Connect the air delivery hose to the warming blanket by pushing the plastic fitting
into the air inlet port.
2.3. Unit Operation Procedure
Select the desired temperature on the control panel pressing either one of the Output
temperature selection buttons (E) or Ambient Temperature Output Button (C). The
appropriate green or yellow light (D or F) will indicate the selected temperature setting. Another
temperature may be selected at any time. The air temperature surrounding the patient will vary
at each setting, depending upon ambient air temperature and the quality of the insulating
blanket or sheet that is used over the warming blanket. When using the 34°C, 37°C, 40°C, 43°C,
or 46°C temperature settings, place your hand under the warming blanket to confirm that the
CWS4000 is supplying warm air. Place a sheet or blanket over the inflated warming bianket to
maximize the efficiency and minimize the heat loss from the system.
The internal timer will automatically decrease the temperature setting from 46°C to 43°C after 10
minutes. This timer can be reset by momentarily selecting another setting and then re-selecting
46°C.
Switch the unit off by pressing the Standby Button (A). The green Standby indicator (B) will
illuminate when the unit is off.
The unit will automatically switch off in an alarm condition and the green Standby indicator (B)
will illuminate together with the red Fault Alarm indicator (H). In the event the Fault Alarm
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Care Essentials CWS4000 Cocoon Warming System Service Manual
indicator (H) illuminates, disconnect the CWS4000 from the patient and from the mains power
supply and have it serviced by trained personnel.
The Filter Status indicator (G) provides the user with information on remaining filter life. This
indicator is interpreted as follows:
Indication Description
Steady green indicator Filter status normal
Steady orange indicator | Filter life has reached 950 hours
Flashing orange indicator | Filter life has reached 990 hours
Steady red indicator Filter life has exceeded 1000 hours and requires replacing
2.4. Symbols
The following symbols are used on the CWS4000:
个 Attention: consult accompanying documents
Dangerous voltage
A Type BF applied part
16°C - 29°C Ambient operating temperature range, indoor use only
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Care Essentials CWS4000 Cocoon Warming System Service Manual
3. SAFETY PRECAUTIONS
Review the following safety precautions prior to servicing the CWS4000.
3.1. Danger
e Explosive hazard. Do not use in the presence of flammable anaesthetic agents.
e Risk of electric shock. Disconnect mains power before servicing the CWS4000.
3.2. Warning
e Ensure that no direct or indirect contact is made between the patient and the communications
connector located on the rear of the CWS4000.
e The CWS4000 must only be opened or serviced by qualified personnel such as certified
biomedical electronics technicians or certified clinical engineers familiar with repair practices
for servicing medical devices, and in accordance with the Service Manual. Damage to the
CWS4000 or malfunction could otherwise result.
e Ensure the CWS4000 is subjected to the specified routine electrical safety and performance
inspections.
e Inthe event of excess fluid contact with the CWS4000 it is recommended that the unit be
disconnected from the mains power supply and checked by qualified personnel.
e Use only in accordance with Operator Manual instructions.
3.3. Caution
e Operate the CWS4000 only in the specified supply voltage range and environmental
conditions and as detailed in Section 11 below.
ο When using an IV pole, do not mount the CWS4000 higher than 1 metre or it could tip over.
e The 46°C setting is not recommended for patients who are non-responsive or with impaired
circulation.
e It is not recommended that the unit be operated after the filter has exceeded the specified
life period.
3.4. Electromagnetic Interference
The CWS4000 has been designed to comply with IEC 601-1-2:2004 (Medical electrical
equipment — Part 1: General requirements for safety. 2. Collateral standard: electromagnetic
compatibility — Requirements and tests) but this does not guarantee that other equipment in the
vicinity will not be affected by the electromagnetic emissions from the CWS4000. Similarly,
other equipment in the vicinity may affect the operation of the CWS4000.
It is recommended that all equipment used near the CWS4000 comply with the relevant
electromagnetic compatibility requirements for that equipment and to check before use that no
interference is evident or disruptive. Increasing the distance between offending devices, and
keeping interconnecting leads as short as possible will help reduce the effect.
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Care Essentials CWS4000 Cocoon Warming System Service Manual
4. PREVENTATIVE MAINTENANCE
4.1. Cleaning
e Clean the CWS4000 control panel, enclosure exterior, and hose with a soft cloth lightly
dampened with a non-staining hospital disinfectant.
e Clean accumulated dirt and lint from the air inlet slots using a vacuum cleaner.
4.2. Electrical Safety Inspection
Care Essentials recommend that the CWS4000 receive regular electrical safety inspections.
Information on the type and frequency of inspections may be obtained from locally published
technical standards.
In Australia, the relevant technical standards are:
e AS3551 Technical management programs for medical devices.
This standard specifies procedures required to develop equipment management programs
for medical devices. Some of these include procedures for acceptance, fault management
and routine testing of medical devices. This standard specifies electrical safety, essential
safety and performance testing.
e AS2500 Guide to the safe use of electricity in patient care.
This standard provides a comprehensive guide to the safe use of electrically operated
equipment used in health care facilities. Measures are detailed to provide and maintain
patient and operator safety, including details of the classes of equipment and electrical
installations to be used for particular medical procedures.
Programmed electrical safety inspections are essential to confirm continued operator and
patient safety. Mandatory, statutory requirements for electrical safety inspections may also
apply.
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Care Essentials CWS4000 Cocoon Warming System Service Manual
4.3. Performance Inspection
Care Essentials recommend that the CWS4000 receive at least an annual performance
inspection to verify CWS4000 functions. The CWS4000 does not require adjustment or
calibration.
Items Required:
e CWS4000 Operator & Service Manuals.
» Digital Thermometer.
STEP PROCEDURE
1 If you have not already done so, read the CWS4000 Operator and Service Manuals.
2 e Place the CWS4000 on a firm, level surface.
e Do not connect the delivery hose to a warming blanket.
e Connect the CWS4000 to mains power.
3 Familiarise yourself with the operation of the CWS4000 by operating the CWS4000 with reference to
the CWS4000 Operator and Service Manuals.
4 The temperature control system is verified as follows:
e Ensure the delivery hose cover is undamaged and that it covers the entire hose.
e Ensure that the environmental conditions are 20°C to 22°C, 30% to 70% relative humidity, non-
condensing.
e Place the digital thermometer sensor in the centre of the delivery hose outlet as shown in
Figure 6.
« Check that the temperature of delivered air stabilises within five (5) minutes following a change in
set temperature.
e Check that the temperature of delivered air corresponds with the set temperature to within +2°C.
e Note that some variation between the set temperature and temperature of delivered air is
possible because of heat loss that occurs in the delivery hose. The magnitude of the heat loss
will depend on the ambient temperature and the degree to which the hose is longitudinally
compressed or extended.
Temperature Sensor
Figure 6 Delivery hose outlet showing temperature sensor position
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Care Essentials CWS4000 Cocoon Warming System Service Manual
4.4. Temperature Limit Thermostat Test Procedure
The CWS4000 temperature limit thermostat test is completely optional and may be performed at
the discretion of those responsible for the technical management of the CWS4000. The
CWS4000 temperature limit thermostat function does not require adjustment, calibration or
performance inspection.
The maximum delivered air temperature is not only limited by the control system but by two
series-connected bimetallic auto-resetting thermostats. These thermostats are located in the
exhaust air stream and will interrupt power to the CWS4000 should the output air temperature
exceed a predetermined limit. Either of these two independently operating thermostats will
remove power from the CWS4000 if the delivered air exceeds a preset high limit temperature,
automatically restoring power when the thermostat temperature fails to a safe level.
This test procedure may be briefly described as follows. The CWS4000 is set up with the
various items required to perform the test. The CWS4000 is energised and operated at a set
temperature of 46°C until it has “warmed up.” The test is commenced through a special process
that switches the heater on continuously, simulating a possible fault condition. The test time and
delivery hose air temperature are monitored. The test is passed if the CWS4000 is de-energised
less than 8 minutes after the test start. The delivery hose air temperature at the conclusion of
the test may be as high as 60°C. Note that this test will only produce a valid result if it is
performed at an ambient temperature of 21°C, or greater.
Items Required:
e CWS4000 Operator and Service Manuals.
e Personal Computer (PC) with a free serial communications (Com) port and a suitable
Terminal program, eg HyperTerminal™, which is provided with Microsoft Windows™,
e Digital Thermometer.
e CWS4000 RS232-Logic Communications Cable
The Cocoon Warming Machine model CSW4000 can have three different versions for the
test cable.
This cable is for the over temperature performance testing.
Details of the three versions are:
A. Machines with Serial Numbers commencing 4-0001 Yellow Dot
B. Machines with Serial Numbers commencing 4-0100 Red Dot
C. Machines with Serial Numbers commencing 4-0200 Green Dot
In the event you need to access any of these cables please contact your location Distributor or
Care Essentials Pty Ltd.
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Care Essentials CWS4000 Cocoon Warming System Service Manual
STEP PROCEDURE
1 If you have not already done so, read the CWS4000 Instruction Manual and Service Manual. Read
all of this procedure.
2 e Place the CWS4000 on a firm, level surface.
e Do not connect the PVC delivery hose to a warming blanket.
e Disconnect the CWS4000 from mains power.
3 e Locate the enclosure rear with the warning label.
e Locate the small black cable socket on the top left of the enclosure rear.
e Insert the cable plug into the socket. It should snap into place.
e Insert the cable D-connector into a free Com port connector on the PC.
4 Place the digital thermometer sensor in the centre of the delivery hose outlet as shown in Figure 6
above.
5 e Connect the CWS4000 to mains power.
e Select the 46°C temperature setting.
e Operate the CWS4000 on the 46°C temperature setting for at least 10 minutes prior to
commencing the thermostat test.
6 While the CWS4000 is “warming up”, start the Terminal program on the PC and select the settings
as follows:
e Select the Com port connected to the Converter cable in Step 4 above.
e Baud rate — 9600, data bits — 8, parity — none, flow control — none.
e Terminal emulation — VT100, character set — ASCII.
e Append line feeds to incoming line ends — enabled.
7 Follow the instructions shown on the Terminal window:
e When a correct connection is established between the CWS4000 and the PC, a dot (.) is
received every second.
e Press the spacebar to display the root screen.
e Press “T” to display the over-temperature thermostat test screen.
e The 46°C temperature setting must be selected in order for the test to proceed.
e To initiate the over-temperature thermostat test, SLOWLY type, “YES” then press the Enter key.
To stop the test, press any key or change the CWS4000 temperature setting.
e The CWS4000 is deemed to have passed the test if a thermostat trips in under eight (8)
minutes.
e Confirm that the thermostat resets after several minutes, restoring power to the CWS4000.
8 e Disconnect the CWS4000 from mains power.
e Disconnect the cable from the CWS4000 and PC.
9 Confirm that the CWS4000 functions correctly by undertaking a performance inspection as detailed
in Section 4.3 above.
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Care Essentials CWS4000 Cocoon Warming System Service Manual
4.5. Filter Replacement
The CWS4000 has a replaceable HEPA filter. Under normal use, replace the HEPA filter inside
the CWS4000 every 1000 operating hours or 12 months, whichever occurs first. The FILTER
STATUS indicator will warn of the need for filter replacement.
Items Required:
e CWS4000 Operator € Service Manuals.
e Philips Number 1 and 2 Screwdrivers.
e 13mm spanner.
e HEPA filter.
STEP PROCEDURE
1 If you have not already done so, read the CWS4000 Operator and Service Manuals.
2 e Place the CWS4000 on a firm, level surface.
e Donot connect the PVC delivery hose to a warming blanket.
e Disconnect the CWS4000 from mains power.
3 e Locate the enclosure rear with the warning label.
e Remove the seven (7) Philips head screws located around the perimeter of the enclosure rear.
e Remove the enclosure rear being careful not to stress cable assemblies that run between the
enclosure front and rear.
e To disconnect the membrane keypad tail from the Control Board, hold the blue connector and
pull. Do not pull the tail itself, as damage will almost certainly result.
4 e Remove the nut and washer securing the HEPA filter.
e Remove the old HEPA filter and discard.
e Install the new HEPA filter.
e Replace the nut and washer securing the HEPA filter.
5 e Connect the CWS4000 to mains power. Exercise care, as there will be dangerous voltages
present on some internal parts of the CWS4000.
e Read and note the run hour meter on the control board. Hour digits are sequentially displayed
followed by an “h", “r’, and a pause.
‧ Mark the HEPA filter with the hour meter reading and date of replacement.
e Record these figures in the CWS4000 service record.
e Reset the filter life 1000-hour counter by pressing and holding the switch in front of the hour
meter display. A steady green FILTER STATUS indicator and a long beep will indicate the
successful reset of the 1000-hour counter.
e Disconnect the CWS4000 from mains power.
6 Replace the rear panel by reversing step 5 above.
7 Confirm that the CWS4000 functions correctly by undertaking a performance inspection as detailed
in Section 4.3 above.
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Care Essentials CWS4000 Cocoon Warming System Service Manual
5. TROUBLESHOOTING
5.1. Warming Blanket Will Not Inflate
e Make sure the CWS4000 is plugged in to an energized mains power socket-outlet.
e Check both ends of the delivery hose for proper connection.
e Check the delivery hose and warming blanket inlet for kinks.
e Check that there are no obstructions to the air inlet slots.
e Check the warming blanket for damage. If air is flowing from the hose, try another warming
blanket. Small rips or tears in the warming blanket may be temporarily repaired with
adhesive tape.
e Request qualified service personne! check for a clogged or dirty filter.
e Check for fault alarm.
5.2. Standby Indicator Will Not Light
e Extremely high storage temperatures (such as those found motor cars on hot summer days)
can cause the temperature limit thermostats in the CWS4000 to actuate. Should this occur,
the STANDBY indicator will fail to light when the CWS4000 is connected to mains power. If
this occurs, simply wait for the CWS4000 to cool down and eventually the thermostats will
automatically reset and the STANDBY indicator will light.
e Request qualified service personnel check for blown mains power fuses.
5.3. Equipment Repairs
Repairs to the CWS4000 should be preformed by qualified personnel such as certified
biomedical electronics technicians or clinical engineers familiar with repair practices for
servicing medical devices, and in accordance with the CWS4000 Service Manual. Damage to
the CWS4000 or malfunction may otherwise result.
6. SCHEMATIC DIAGRAM DESCRIPTION
This section describes the CWS4000 schematic diagrams. Reference should be made to the
printed circuit board (PCB) component legend contained in Section 7 and the schematic
diagrams contained in Section 8 below.
The following should assist with the interpretation of the Schematic Diagrams:
e The schematic diagrams are organised in a flat structure.
e Electrical connectivity is shown by continuous wires or net labels on partial wires.
e Netlabels (signal names) are prefixed with a forward slash when they are asserted with
logic “0” (eg: /SIGNAL).
The CWS4000 Control Board implements the following functions:
e Microcontroller.
» RS232 transceiver (Control Board revision E and later).
ο Microcontroller reset circuit.
e Fan control.
e Heater control.
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Care Essentials CWS4000 Cocoon Warming System Service Manual
e LED display drivers.
e Run hour meter display.
e Filter life hour counter reset switch.
e Buzzer.
e Power supplies.
The CWS4000 Sensor Board implements the following functions:
» Digital temperature sensor.
e Temperature limit thermostats.
The more important of these functions are elaborated below.
6.1. Control Board
Microcontroller
The microcontroller (U1) integrates a number of functions:
e CPU.
e Program ROM.
e RAM.
e EEPROM.
ο Interrupt controller.
e External interrupts.
e Counter/Timers.
e Watchdog timer.
e Digital Input/Output ports.
The microcontroller performs the following functions:
e Monitors the exhaust air temperature through the digital temperature sensor.
Monitors the push-button switches.
Controls the display and buzzer drivers.
Controls the heater and fan.
The microcontroller ROM is factory programmed with the application software program. The
software program contained in the microcontroller ROM is subject to copyright. In the event of a
microcontroller fault, Care Essentials must fit a replacement part.
Reset Circuit
When the microcontroller is reset either by power-on or by the watchdog timer:
e Digital Input/Output ports 0 — 3 go high.
e Signal /FAN goes low switching on the fan relay.
The fan blower is switched on.
e Signal /HEAT goes high switching off the heater triac.
The heater is switched off.
Thus the reset process implements a safety strategy to prevent the fan biower being turned off
with the heater being turned on.
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Care Essentials CWS4000 Cocoon Warming System Service Manual
Power-On Reset
Following power-on capacitor (C3) charges from zero to +5V (VCC) through resistor (R1)
connected to ground. This causes the Reset input of the microcontroller to be momentarily
asserted high. The microcontroller type used on Control Board revision E and later has an
internal power-on reset circuit and capacitor (C3), resistor (R1) and diode (D1) are not fitted.
Watchdog Reset
The microcontroller watchdog timer is incremented regularly by the microcontroller hardware.
When a watchdog timer overflow occurs the microcontroller is reset.
To prevent such a system reset the microcontroller watchdog timer is reloaded before it
overflows by the application software program. If the microcontroller suffers a hardware or
software malfunction, the application software program will fail to load the microcontroller
watchdog timer. This failure will produce a system reset on overflow thus preventing the
microcontroller from running out of control. This prevents a potentially hazardous situation from
occurring.
6.2. Sensor Board
Digital Temperature Sensor
The temperature sensor (U1) is controlled by and communicates with the Control Board
microcontroller (U1).
Temperature Limit Thermostats
The maximum air temperature is not only limited by the control system but by two series-
connected bimetallic auto-resetting thermostats. These thermostats are located in the exhaust
air stream and will interrupt power to the CWS4000 should the output air temperature exceed a
predetermined limit. The temperature limit thermostat function does not require adjustment,
calibration or performance inspection.
6.3. System Block Diagram
The System Block Diagram shows the general electrical connectivity between the various
CWS4000 electrical and electronic subassemblies:
e Power inlet module including EMI filter and fuses.
e Temperature limit thermostats.
e Heater.
e Fan blower.
e Control Board.
e Sensor Board.
e Communications connector.
Before removing any of the connections between the electrical and electronic subassemblies,
make a careful note so that these may be correctly reinstated. Incorrect connections could
compromise patient safety and/or damage the CWS4000.
The System Block Diagram is presented as an aid to understanding the CWS4000 and does
warrant extensive discussion.
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Care Essentials CWS4000 Cocoon Warming System Service Manual
7. BOARD COMPONENT LEGENDS
7.1. Control Board
ーー Not fitted
ον > when U1 is
AT89S8253
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Care Essentials CWS4000 Cocoon Warming System Service Manual
7.2. Sensor Board
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CWS4000 Cocoon Warming System Service Manual
Care Essentials
SCHEMATIC DIAGRAMS
8.
Control Board Schematic Diagram
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Care
Essentials
CWS4000
Cocoon
Warming
System
Service
Manual
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Board
Schematic
Diagram
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