Thermo Scientific Centra-W Cell Washer User manual

SERVICE
MANUAL
SM2392
Revision 1
Centra-W
CellWasher
Cat. No. 2392 -- For 100/120/220/240 VAC, 50/60 Hz

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Centra-W Cell Washer Service Manual
TABLE OF CONTENTS
1DESCRIPTION ................................................................................................................. 4
2INSTALLATION ................................................................................................................ 5
2.1 ReceivingInspection ................................................................................................... 5
2.2 Unpacking ................................................................................................................... 5
2.3 PowerConfiguration.................................................................................................... 7
Voltage........................................................................................................................ 7
Fuses .......................................................................................................................... 7
Power Cord ................................................................................................................. 8
2.4 TubingInstallation ....................................................................................................... 8
3 OPERATION ...................................................................................................................... 9
3.1 ControlPanel .............................................................................................................. 9
3.2 Description of Operation.............................................................................................. 11
3.3 OperationalPrecautions.............................................................................................. 13
3.4 Saline Solution - Priming and Volume Calibration ....................................................... 13
Priming........................................................................................................................ 13
VolumeCalibration ...................................................................................................... 14
3.5 Wash Mode................................................................................................................ 15
3.6 Spin Mode................................................................................................................... 16
Timed.......................................................................................................................... 16
Untimed (Hold) ............................................................................................................ 16
3.7 AgitateMode............................................................................................................... 16
3.8 OperatingProcedure ................................................................................................... 17
3.9 Anti-HumanGlobulin ................................................................................................... 18
4MAINTENANCE................................................................................................................ 19
4.1 PreventiveMaintenance.............................................................................................. 19
Daily............................................................................................................................ 19
Weekly ........................................................................................................................ 19
Three Months .............................................................................................................. 20
4.2 ReplacementParts...................................................................................................... 21
4.3 Guard Bowl Removal .................................................................................................. 21
4.4 Pump Tubing Replacement ......................................................................................... 21
4.5 Decontamination ......................................................................................................... 23
4.6 Cover Interlock Bypass ............................................................................................... 24
5WARRANTY ..................................................................................................................... 25
5.1 Condition Of Returned Equipment............................................................................... 25
6 SPECIFICATIONS.............................................................................................................. 26

2Centra-W Cell Washer Service Manual
7SERVICE .......................................................................................................................... 27
7.1 Warnings And Cautions............................................................................................... 27
7.2 General ....................................................................................................................... 27
7.3 Troubleshooting .......................................................................................................... 28
8CABINET .......................................................................................................................... 29
8.1 CabinetRemoval......................................................................................................... 29
8.2 Control Panel Removal ............................................................................................... 29
8.3 Latch Assembly........................................................................................................... 29
8.4 Hinges......................................................................................................................... 30
8.5 Cover Assembly .......................................................................................................... 31
8.6 BaseAssembly Components ...................................................................................... 31
9 POWER.............................................................................................................................. 32
9.1 Power Circuit............................................................................................................... 32
9.2 BlowingFuses............................................................................................................. 32
10 CIRCUIT BOARD.............................................................................................................. 34
10.1 General ................................................................................................................. 34
10.2 LEDs ..................................................................................................................... 34
10.3 Fuse ...................................................................................................................... 35
10.4 Test Points ............................................................................................................ 35
11 DRIVEASSEMBLY........................................................................................................... 36
11.1 General ................................................................................................................. 36
11.2 Motor..................................................................................................................... 36
11.3 Brake..................................................................................................................... 37
11.4 DecantSolenoid .................................................................................................... 37
11.5 Rotor Repair.......................................................................................................... 37
11.6 Rotor Dependant Parts.......................................................................................... 40
12 PUMP .............................................................................................................................. 41
12.1 General ................................................................................................................. 41
12.2 Pump Motor........................................................................................................... 41
12.3 Flow Switch ........................................................................................................... 42
13 DRAWINGS...................................................................................................................... 43
IMPORTANT
This manual may not contain information on all changes that have occurred to the subject instru-
ment since the manual issue date. It was prepared for use by IEC authorized factory-trained
service or dealer personnel who are kept current through a program of service letters and bulletins
and training seminars.
This manual contans WARNINGS against operating procedures which could result in an accident
and/or personal injury. It also contains CAUTIONS against procedures which could result in
damage to your centrifuge or accessory equipment. Read this manual thoroughly before operating
or servicing this centrifuge.

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Centra-W Cell Washer Service Manual
LIST OF ILLUSTRATIONS
Figure Page
2-1 Unpacking..................................................................................................5
2-2 Voltage Selection.......................................................................................7
3-1 Centra-W Wash Cycle .............................................................................11
3-2 Rotor And Plunger Installation.................................................................14
4-1 Pump Assembly.......................................................................................21
4-2 Cover Interlock Bypass............................................................................23
Chapter 13 Drawings ......................................................................................43

4Centra-W Cell Washer Service Manual
1 DESCRIPTION
The Model Centra-W Cell Washer is manufactured by the International
Equipment Company. This benchtop cell washer is used to automatically
perform the washing phase of the anti-globulin procedure in tests using up to
six drops of blood sample. The cell washer will accommodate either twelve 12
x 75 mm tubes, or twelve 10 x 75 mm tubes. It is registered as a device in
accordance with FDA regulations governing the distribution and use of such
products.
The Cell Washer incorporates a power entry module which permits you to
select operation with 100, 120, 220, 230 or 240 Vac, 50/60 Hz power.
The Centra-W cell washer contains a microprocessor-controlled centrifuge
and a peristaltic pump for dispensing saline solution.
A cabinet supports a centrifugation chamber which is a removable plastic
guard bowl. A drive assembly is mounted to the cabinet base. An induction
motor is mounted to the drive assembly providing brushless operation. The
motor has permanently-sealed self-lubricating ball bearings. The motor shaft
projects through the center of the guard bowl. A solenoid plunger and a rotor
is set on the motor shaft. A cover assembly forms the top section of the
chamber. The aluminum cover assembly consists of a feed-dispensing
nozzle for inserting saline solution into the tubes in the rotor, a cylindrical
splash guard for directing the decanted waste into the drain hole in the
chamber, a latch, and a viewport for easy speed verification.
When the cover is closed and latched, an interlock prevents the cover from
opening when the rotor is in motion. The interlock also prevents operation
when the cover is not closed and latched except in the CALIBRATE and
AGITATE mode. The remaining electrical and electronic components, along
with the saline solution peristaltic pump and the rotor drive assembly, are
located on the base section of the cabinet.

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Centra-W Cell Washer Service Manual
2 INSTALLATION
2.1 Receiving Inspection
The Cell Washer is shipped in a special carton designed to protect it from
hazards in transit. Before signing the delivery receipt and accepting the
shipment, inspect the shipping carton for any signs of mishandling, such as
broken or dented sides or SHOCKWATCH® activation. Any observed
damage must be stated, in writing, on the delivery receipt before signing the
receipt. A normal or undamaged carton does not necessarily ensure that the
contents are undamaged. If mishandling or shipping damage is suspected,
contact the office of the carrier so that a representative may be called in to
witness the unpacking. IEC is not responsible for damage incurred in transit.
2.2 Unpacking
CAUTION: The Cell Washer weighs 45 lbs. (20.4 kg). Unpacking
and installation may require two people. Do not use any
sharp instrument to open the inner carton packaging,
damage to the instrument may result.
Note: Refer to Figure 2-1 while unpacking.
1. Remove the small box containing the rotor (Figure 2-1).
2. Remove the Power Cords and fuses.
3. Remove the top cardboard supports.
4. Remove the cardboard protector from the Cell Washer.
5. Grip the cell washer under the top edge of the front panel and
under the top edge of the pump enclosure and lift it free of the
carton. (Have someone hold the carton, if necessary).
6. Place the cell washer on a sturdy, level bench near a waste
container or drain to receive decanted saline.

6Centra-W Cell Washer Service Manual
CAUTION: The bottom of the cell washer must be high enough so
that the drain hose is pitched downward from the unit to
the drain, with no restriction to gravity flow. The drain
hose may not be extended or constricted. Reduction of
the drain flow can cause saline back up resulting in
seriouscorrosion damage.
Allow a minimum of 12 cm (5 in.) of clearance on all
sides of the cell washer for proper air cooling
circulation.
Do not plug in the power cord. The Cell Washer should
not be turned on at this time.
7. Carefully inspect the cell washer
for external damage. Any
damage discovered which is
attributable to mishandling or
shipping should be documented,
and a signed inspection report
should be furnished to the
shipping company.
8. Complete the warranty
registration card and return it to
IEC.
Figure 2-1 Unpacking

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Centra-W Cell Washer Service Manual
Voltage
Fuse
Cat No.
100V/120V
250V 5A T
49946
220V/240V
250V 2.5A T
49937
2.3 Power Configuration
The Cell Washer uses AC power at 100,120, 220, 230 or 240 volts, at 50 or
60 Hz. The unit is shipped without fuses installed and must be configured for
power at your site. Do not plug in the cell washer until you have
configured it correctly. Variations in line voltage or frequency will affect the
unit’s speed and other characteristics.
Caution: configuring the cell washer incorrectly will void your warranty.
Voltage Note: Refer to figure 2-2 while performing this procedure.
Locate the power entry module on the rear of the unit (Figure 2-2). On the
right side of this module is the fuse drawer. A small latch on the left holds the
drawer in place. Press the latch and slide the drawer out. When removing the
fuse drawer, be careful that the fuses do not fall out.
If the number visible in the window differs from the voltage at your site,
remove the square insert, rotate it, and reinstall it so that the correct voltage is
displayed through the window and insert appropriate fuse value (see chart
below).
Note: Use 240V fuse drawer position for 230V service.
CAUTION: This instrument must be configured for the correct line
voltage and must have correct fuse values. Incorrect
settings may cause fuses to blow and/or cause damage
to electrical controls.
Fuses From the following table, determine the correct fuses. Insert two fuses in the
fuse drawer and replace the fuse drawer in the power entry module. Make
sure it locks into place.
220V/230V/240V

8Centra-W Cell Washer Service Manual
Figure 2-2 Voltage Selection
Power Cord The unit requires a grounded power supply (3-prong receptacle). If your
facility does not have properly grounded power outlets, arrange for proper
grounding. Do not remove the power cord plug to attach a power plug that
does not have a grounding pin.
WARNING: Grounding - this instrument is equipped with a three
prong plug for safety purposes. The wall outlet must be
a three wire receptacle (one being GROUND). If the
outlet is not, then contact an electrician for wiring
changes.
The unit is provided with two power cords. One is suitable for North America
and Japan. The other is a “Continental Europe” type. Attach the appropriate
power cord to the power entry module receptacle on the Cell Washer. Do not
connect to AC outlet at this time.
2.4 Tubing Installation
The cell washer is shipped with the pump tubing already installed in the
peristaltic pump at the rear of the cell washer. The saline supply tubing
(including volume control flow valve and supply adapter) is also connected
(by a 90° elbow) to the pump tubing which extends from the pump. Connect
the saline supply tubing to a saline solution supply container using the
adapter.
NOTE: The cell washer has a gravity drain. Therefore be sure the drain
tubing flows downward and that it is not restricted in any way.
For best results, locate the cell washer next to a sink for
draining purposes. Periodically inspect the drain tubing to
ensure its proper operation. If the drain line becomes kinked or
restricted, drained liquid can back up the drain hose and into
the motor compartment causing motor failure.

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Centra-W Cell Washer Service Manual
3 OPERATION
3.1 Control Panel
The membrane control panel contains switches which are actuated by
pressure. The switches will sound (beep) when pressed. Indicators light when
corresponding keys are pressed.
Power Switch The Power Switch is located at the front lower-right of the cabinet. This
On-Off rocker switch is used to control the main power coming from the line
cord at the rear of the cabinet. When the Power Switch is pushed to the ON
position the STOP and the OPEN COVER light emitting diode (LED)
indicators on the control panel will light and zeroes will appear in the TIME
and CYCLE digital displays.
Run This key is used to start the wash or spin run. The indicator to the left of
this key will light when the RUN key is pressed, indicating that the instrument
is in the run mode.
Stop This key may be used at any time and in any mode to stop a run. The
indicator to the left of this key will light when the stop key is pressed,
indicating that the unit is in the brake mode.
Note: No changes can be made during a run. All keys are disabled except
for the STOP and CHECK keys.
Check This key is used to temporarily interrupt a wash cycle at the end of its current
phase (i.e. at the end of fill, spin, decant, or agitate). The cover may be
opened (by pressing the OPEN COVER key once the OPEN COVER LED
lights) for access to the rotor. Closing the cover and pressing the RUN key
will resume the wash cycle run where it was interrupted. The check function
can only be used in the wash mode. The indicator to the left of this key lights
when the CHECK key is pressed to signal that the unit is in the check mode.
Open Cover This key is used to power the cover solenoid and open the cover. The
indicator to the left of this key will light whenever the Power Switch is in the
On position and the rotor is stopped. Press the OPEN COVER key to release
the cover.

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Clear This key is used to clear the currently displayed TIME or CYCLE numbers.
Numbers These keys are used to select the desired number of wash cycle(s) in the
wash mode (1-4), or to select the duration of a timed (1-999 seconds) spin
mode. The selected time in seconds will appear in the TIME display.
Hold This key is used to select an indefinitely timed spin run.
Wash This key is used with the 1, 2, 3 or 4 number keys to enter the desired wash
cycle(s). The indicator to the left of this key will light when the WASH key is
pressed indicating that the instrument is in the wash mode. A beep will sound
at the end of the wash cycle.
Spin This key is used with the appropriate number (0 through 9) key(s) to use the
cell washer as a centrifuge at 2800 rpm (50 Hz) or 3400 rpm (60 Hz) in a
timed (from 1 to 999 seconds) run or in an untimed run using the HOLD key.
The indicator to the left of this key lights when the SPIN key is pressed
indicating that the unit is in the spin mode.
Agitate This key is used to select a six-second agitation for resuspension of the
cell button.
Calibrate This key is used to select the calibrate mode in order to set the correct
volume of saline solution dispensed for each test tube. It is also used in
priming the peristaltic pump.
Time This digital display will show the total time of the spin, or wash, cycle(s) at the
start and the remaining time while running. Time shows a maximum of 999
seconds, or 000 for HOLD.
Cycle This digital display will show the number of wash cycles initially selected, and
during the run, the current wash cycle(s) left.
Saline This indicator lights when the saline solution reservoir is depleted. An alarm
also sounds. The cell washer defaults to the check mode, allowing the user to
hand-fill the tubes, and to prime the pump system. Pressing the RUN key will
resume the run.

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Centra-W Cell Washer Service Manual
3.2 Description of Operation
The cell washer can be programmed to run up to four wash cycles. Each
basic 80-second wash cycle run is stored in the cell washer system memory
until the CLEAR key is pressed, the power switch is pushed, the power is
interrupted or the wash mode parameters are changed. The user programs
the required number of wash cycles. The system automatically eliminates the
“agitate” step from a single, or, the final wash cycle so that the clean pellet is
well defined at the completion of the run.
Each wash cycle consists of four steps (Refer to Figure 3-1):
1 . FILL-Low Speed
Saline wash solution is drawn from the reservoir by the peristaltic
pump up through the flow control valve, the flow switch and the cover
saline dispensing nozzle. The nozzle feeds the saline into the inlet
porthole in the rotor distributor. There the filler tubes feed the saline into
the test tubes in a directed stream for maximum resuspension of cells.
2. SPIN-High Speed
The system rapidly accelerates to full speed to pellet the red blood cells.
Automatic dynamic braking at the end of this step provides rapid
deceleration to prevent resuspension or dislodging of the cell button.
3. DECANT-Low Speed
The rotor holds the tubes at a slight negative angle and spent saline is
expelled from the test tubes by low centrifugal force. This action retains
virtually all cells in the tubes while effectively removing almost all
residual saline. Decanted waste solution is directed, by the splash guard
in the cover, into the drain-hole in the chamber (guard bowl) and into
the drain tubing which carries the waste out of the cell washer and into a
waste container or drain.
4. AGITATE (except in a single or final wash cycle)
This phase is included on all but the final, or a single, wash cycle. By a
rapid “stepping" motion of the rotor, cell pellets are disrupted (broken up)
for resuspension of the cells during subsequent wash cycles. If desired,
the agitation sequence may be manually added at the end of the run.

12 Centra-W Cell Washer Service Manual
Figure 3-1 Centra-W Wash Cycle

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Centra-W Cell Washer Service Manual
3.3 Operational Precautions
To guarantee accurate test results, the proper use of the cell washer as
described herein and in the testing procedure provided by the reagent
manufacturers must be followed explicitly. Also, be sure that test materials
are used within the manufacturers recommended dates.
Erroneous antiglobulin readings can result from any of the following:
• The sample serum/cell ratio is improper.
• The red cells were not sufficiently washed.
• The saline solution was improperly decanted.
• The volume calibration has shifted due to change in the saline level or
restriction in the feed tube.
• The antiglobulin serum is inactive or outdated.
• The antiglobulin serum was not added to a tube(s).
• The final centrifugation (spin) was improper.
• The reading or recording of results is inaccurate.
This cell washer provides accurate washing, decanting, and a proper speed
for the final spin. However, the cell washer and the procedures outlined
herein will not eliminate all potential errors. To minimize errors, proper
laboratory procedures require adequate control of all tests performed.
WARNING: When handling and disposing of blood and blood
componentsfollow standardlaboratory procedures.
Observe all safety precautions and standard laboratory
practices.
3.4 Saline Solution - Priming and Volume Calibration
WARNING: Some saline solution contains a sodium azide
preservative which may react with the drain plumbing to
form dangerous explosive azide salts. Check with the
saline solution supplier before discharging waste
solutions directly into normal drains.
Long-term exposure to certain preservatives found in azide-free saline
solutions may adversely effect certain plastic components within the cell
washer. Routine housekeeping and cleaning practices will help to remove salt
deposits in, and prolong the life of, these components.
Priming Priming is required whenever a new saline supply is connected.
To prime the instrument:

14 Centra-W Cell Washer Service Manual
1. Connect the saline reservoir to the cube adapter of the pump tubing.
2. Open the cover and place a receptacle under the saline dispenser nozzle
in the cover.
NOTE: When priming or calibrating the pump with the cover open
always put a container in front of the nozzle before pressing the
calibrate key. (Otherwise, you will get wet!)
3. Press the CALIBRATE key. Saline will enter the lines. If saline does not
reach the receptacle, press the CALIBRATE key again until the lines are
full of saline solution and free of air bubbles.
Volume Calibration This procedure provides the correct volume of saline solution to be
distributed to each test tube.
Calibration is required daily. Calibration is also required if the saline
reservoir has been replaced or pump tubing replaced.
1. Push the Power Switch to the on position.
2. The OPEN COVER LED lights.
3. Press the OPEN COVER key.
4. The cover will open.
5. Hold a 100 ml graduated cylinder directly under the saline dispenser in
the cover.
NOTE: When priming or calibrating the pump with the cover open
always put a container in front of the nozzle before pressing
the calibrate key. (Otherwise, you will get wet!)
6. Press the CALIBRATE key. A volume of saline will dispense into the
cylinder. This volume should be:
VOLUME TOTAL TUBE SIZE
54 ml 12 x 75 mm tubes
40 ml 10 x 75 mm tubes
If volume is not correct, turn the flow valve on the saline supply tubing
clockwise (CW) to decrease volume flow and counter clockwise (CCW) to
increase volume flow. Recheck by following this procedure starting at step 5.
Repeat this procedure as necessary.
The cell washer must be Calibrated for a 12 tube load even though fewer
tubes may be used.

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Centra-W Cell Washer Service Manual
3.5 Wash Mode
Wash Cycle The wash mode can consist of 1, 2, 3 or 4 wash cycles. To perform an
automatic wash:
Push the POWER SWITCH to the ON position. The TIME and the CYCLE
displays will show zeroes. The STOP LED and OPEN COVER LED will light.
Press the OPEN COVER key and raise the cover. Install the solenoid
plunger onto the drive assembly shaft. Turn the solenoid plunger
counterclockwise (CCW) until the slot in its underside completely engages the
pin in the drive assembly
shaft. The solenoid
plunger is correctly
seated when it cannot be
turned independently of
the motor shaft.
Carefully install and seat
the rotor onto the drive
assembly shaft. Turn
the rotor
counterclockwise (CCW)
until it rests on the drive
assembly shaft and
engages the slot at the
top of the drive assembly
shaft. The rotor is
properly seated when it
cannot be turned
independently of the
solenoid plunger.
Install tubes
symmetrically in the
rotor. Figure 3-2 Rotor And Plunger Installation
CAUTION: The rotor must be run with a balanced load or
damage to the rotor and instrument can occur.
Close the cover and press the WASH key. Press the appropriate number
key 1, 2, 3 or 4 for the desired wash cycle(s). The selected cycle number will
appear on the CYCLE display. Also, the TIME display will show 80,160, 240
or 320 seconds for the respective 1, 2, 3 or 4 wash cycles. Press the RUN
key. The RUN LED will light, and the TIME display will show the run time
remaining.
You may stop the run by pressing the STOP key for immediate braking or
pressing the CHECK key to pause after the current step (Fill, Spin, Decant or
Agitate). If the STOP key was used, then the wash cycle will start from the
beginning when restarted.
NOTE: If saline flow is interrupted or depleted, the run stops, an alarm
sounds and the ADD SALINE LED lights. (See Section 3.4)

16 Centra-W Cell Washer Service Manual
The CHECK key is operable only in the WASH mode. Pressing the CHECK
key stops the run between two steps. The run will continue from there when
the cover is closed and the RUN key is pressed.
At the end of the run the OPEN COVER LED will light, and an alarm will
sound. Press the OPEN COVER key and raise the cover.
3.6 Spin Mode
In this mode the cell washer can be operated at high speed as a centrifuge in
a timed run or in an untimed (HOLD) run.
Timed Press the SPIN key and enter the desired centrifugation run time from I
through 999 seconds. The selected time will appear on the TIME display.
Press the RUN key. In the timed mode the rotor will accelerate to, and spin
at, high speed for the designated time. The remaining time to spin will be
displayed continuously in the TIME display and then the unit will shut off
automatically.
NOTE: If agitation is desired prior to spin: press the SPIN Key; press
the AGITATE key, then press the appropriate run time keys.
Now the instrument is programmed for a six-second agitation
prior to centrifugation.
Untimed (Hold) Press the SPIN key and then press the HOLD key. Press the RUN key.
The rotor will accelerate to, and spin at, high speed until the STOP key is
pressed.
3.7 Agitate Mode
NOTE: Agitation can be performed with the cover open or closed.
Press the AGITATE key to obtain a six-second agitation. An agitate can be
added to the spin cycle by pressing the SPIN and AGITATE keys.

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Centra-W Cell Washer Service Manual
3.8 Operating Procedure
1. Press the POWER switch to the ON position (The STOP LED and the
OPEN COVER LED will light and the TIME and CYCLE displays will
show zeroes).
2. Press the OPEN COVER key and raise the cover.
3. Install the tubes symmetrically in the rotor.
CAUTION: The rotor must be run with a balanced load or
damage to the rotor and instrument can occur.
4. Close the cover.
5. Press the WASH Key.
6. Press the desired number of washes (1-4).
7. Press the RUN Key to initiate the wash cycle.
8. The STOP LED, and the OPEN COVER LED will light when the
wash cycle(s) is complete. Press the OPEN COVER key and raise the
cover.
9. Add the appropriate amount of anti-human serum to the tubes.
10. Close the cover. Press the SPIN key and, if desired, the AGITATE key.
(If AGITATE key is pressed the tubes will be agitated for six-seconds
and then spun).
11. ENTER the number of seconds for the desired cycle time.
12. Press the RUN key to begin the spin cycle.
13. At the end of the entered time the STOP LED and the OPEN COVER
LED will light. When the spin cycle(s) is complete; press the OPEN
COVER key and raise the cover. Remove the tubes and read the
results.
14. Add lgG-sensitized control cells to all negative reactions and replace the
tubes in the rotor. Be sure the load is symmetrically balanced.
15. Repeat steps 12 and 13.
NOTE: Once the preceding programmed wash and spin cycles have
been entered, they remain in the memory unless the CLEAR
key is pressed, the Power Switch is pushed, the wash mode
parameters are changed or the power is interrupted.
Therefore, simply press the WASH key or SPIN key. Then
press the RUN key. The run cycle will include all the
previously entered number of wash cycles or spin time, and
agitate, if programmed.

18 Centra-W Cell Washer Service Manual
3.9 Anti-Human Globulin
The following Anti-Human Globulin Test protocol can be used as a check of
proper cell washer operation.
Perform the operational tests with a full rotor of twelve (12) either the
10 mm x 75 mm tubes or the 12 m x 75 mm tubes as described below:
1. Add up to six (6) drops of AB serum and one (1) drop of a 2-5% red cell
suspension in each tube.
2. Run the tubes through three (3) wash cycles with tubes at least 80% filled
[approximately 40 ml total for twelve (12)10 x 75 mm tubes and 54 ml
total for twelve 12 x 75 mm tubes for each wash].
3. Add two (2) drops of anti-human serum to each tube.
4. Agitate tubes and spin for 15-20 seconds. Examine for agglutination. All
tubes should give negative reactions.
5. Add one (1) drop of Coombs control cells to each negative tube.
6. Agitate tubes and spin for 15 seconds. Examine for agglutination. All
tubes should give positive reactions.

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Centra-W Cell Washer Service Manual
4 MAINTENANCE
4.1 Preventive Maintenance
Daily 1. Inspect tubing and connections.
Make sure all tubing is securely connected and free from obstructions. Make
certain that drain tubing is not restricted and that saline waste can flow
through freely by gravity.
2. Inspect interior bowl (Remove guard bowl).
Make certain that the bowl is clean and free of dried saline crystals and other
debris. It is important to wipe out the bowl daily with a damp sponge or cloth.
3. Check saline fill volume.
Using the CALIBRATE key and a graduated cylinder, make certain the unit
delivers 40 mL of saline if using 10 x 75 mm tubes or 54 mL if using
12 x 75 mm tubes. It the volume delivered is below the required amount
adjust the saline flow valve (clockwise to decrease the amount of saline and
counterclockwise to increase the flow).
Weekly 1 . Flush tubing with a 1:10 solution of household bleach (0.5% Sodium
Hypochlorite).
Prepare enough diluted bleach to run through four wash cycles
(approximately 200 ml). Remove the saline supply tube from the saline
reservoir. Press the CALIBRATE key until all saline is pumped out of the line.
Connect the saline supply line to the bleach solution and program the unit to
Wash 4 (four) times. Remove the saline supply line from the bleach solution
and again empty the line by pressing the CALIBRATE key. Then connect the
saline supply tubing to at least one Iiter of distilled water and fill the line by
pressing the CALIBRATE key. Run the unit through enough Wash cycles to
use all of the distilled water. Again clear the line using the CALIBRATE key.
Reconnect the saline supply line to the saline reservoir and prime the unit
using the CALIBRATE key. Make certain that the inner bowl is wiped out to
remove any excess moisture before resuming use of the cell washer.
2. Clean the rotor and solenoid plunger.