Hettich EBA 20 Setup guide

08.08 Andreas Hettich GmbH & Co. KG AR2002EN
EBA 20
EBA 20 C
Repair instructions

2/31
Andreas Hettich GmbH & Co. KG
Föhrenstraße 12, D-78532 Tuttlingen / Germany
Phone [phone]
Fax [phone]
[email protected], [email protected]
www.hettichlab.com
© 2007 by Andreas Hettich GmbH & Co. KG
All rights reserved. No part of this publication may be reproduced without the prior
written permission of the copyright owner.
Modifications reserved!
AR2002EN / 08.08

3/31
Contents
1Introduction ..............................................................................................................5
2Symbol meanings.....................................................................................................5
3Description of the centrifuge.....................................................................................6
3.1 Control panel A3 ...............................................................................................7
3.2 Power board A1 ................................................................................................7
3.3 Motor M1...........................................................................................................7
3.4 Lid lock Y1 ........................................................................................................8
3.5 Imbalance switch S2 (only with EBA 20 C) .......................................................8
4Troubleshooting procedures.....................................................................................8
5Error messages........................................................................................................9
5.1 MAINS RESET..................................................................................................9
5.2 Brief description ................................................................................................9
5.3 Description and elimination of errors...............................................................10
5.4 Defects without Error indications.....................................................................12
6Settings and enquiries............................................................................................14
6.1 Setting the machine version............................................................................14
6.2 Enquiry the machine version...........................................................................15
6.3 Enquiry the programme versions ....................................................................16
6.4 Setting the brake step.....................................................................................17
6.5 Locking the input of the speed, time and brake step and locking the
key
(only with EBA 20 C)............................................................................18
6.6 Lid lock control................................................................................................18
6.7 Imbalance switch-off (only with EBA 20 C) .....................................................19
7Change mains input fuse........................................................................................19
8Functional check after a repair...............................................................................20
9General arrangement of the components...............................................................21
10 Assembling and disassembling components......................................................22
10.1 Replacing the carbon brushes ........................................................................22
10.2 Motor M1 / Rubber-metal bearing ...................................................................22
10.3 Power board A1 ..............................................................................................23
10.4 Control panel (A3)..........................................................................................23
10.5 Flat ribbon cable..............................................................................................23
10.6 Appliance plug with mains switch....................................................................23
10.7 Imbalance switch S2 (only with EBA 20 C) .....................................................23
10.8 Lid lock Y1 ......................................................................................................23

4/31
11 Technical documents ......................................................................................... 24
11.1 Connecting diagrams...................................................................................... 24
11.1.1 Abbreviations of the cable colours...........................................................24
11.1.2 Connecting diagram EBA 20 / EBA 20 C................................................. 25
11.2 Signals and measurements ............................................................................ 26
11.2.1 Motor M1 ................................................................................................. 26
11.2.2 Speedsensor B3 (speedometer).............................................................. 26
11.2.3 Lid lock Y1...............................................................................................27
11.2.4 Imbalance switch S2 (only with EBA 20 C)..............................................27
11.3 Technical specifications.................................................................................. 28
12 Index ..................................................................................................................30

5/31
1 Introduction
• Repairs must only be carried out by personnel authorised to do so by the
manufacturer.
Interventions and modifications at centrifuges, which have been conducted
by persons not authorized by the Andreas Hettich GmbH & Co. KG
company, are at their own risk and entail the loss off all guarantee and
liability claims. In such an event any guarantee claim or liability claim
against the Andreas Hettich GmbH & Co. KG company expire.
• Only original spare parts and original accessories licensed by the Andreas Hettich
GmbH & Co. KG company are allowed to be utilised.
If no original spare parts or no original accessories are used, any guarantee
claim or liability claim against the Andreas Hettich GmbH & Co. KG
company ceases to exist.
• Information about the operation of the centrifuge please see operating instructions.
• We reserve all rights for these technical documents.
2 Symbol meanings
Symbol on the machine:
Attention, general hazard area.
Before using the centrifuge implicitly read the operating instructions and pay
attention to the safety relevant references!
Symbol in this document:
Attention, general hazard area.
This symbol refers to safety relevant warnings and indicates possibly
dangerous situations.
The non-adherence to these warnings can lead to material damage and injury
to personal.
Symbol in this document:
Warning! Danger for human lives by electric shock.
Symbol in this document:
This symbol refers to important circumstances.
Symbol on the machine and in this document:
Symbol for the separate collection of electric and electronic devices according
to the guideline 2002/96/EG (WEEE). The device belongs to Group 8 (medical
devices).
Applies in the countries of the European Union, as well as in Norway and
Switzerland.

6/31
3 Description of the centrifuge
The EBA 20 / EBA 20 C is a microprocessor-controlled centrifuge which is comprised of
the following electrical components:
• Control panel
• Power board
• Motor with speed sensor (speedometer)
• Lid lock system
• Imbalance switch (only with EBA 20 C)
All electronic components are on mains, due to the DC-coupling
Netz / Mains
Verschluß / Lid lock
Deckelschalter
Lid switch
Unwucht
Imbalance
Drehzahlsensor (Tacho)
speed sensor (speedometer)
Leistungsteil
Power board
mit Mikroprozessorsteuerung
und Motoransteuerung
with microprocessor control
and motor control
Steuerteil LED / Control panel LED
EEPROMSchnittstelle / Interface
Motor

7/31
3.1 Control panel A3
The control panel have only restricted control tasks, it disposes of the following
characteristics:
• Input panel for operation parameters
• Indication elements
• Transmission of the signals to the power board via the interface.
• Storing of centrifuge version
• Storing the machine version and the brake setting.
By means of the machine version the power board is informed which kind of
centrifuge has to be controlled. Then the power board takes the corresponding
values from the ROM.
e.g. Max. Speed
Acceleration and deceleration ramps
• Communication with the power board via TTL interface.
The power supply for the control panel is transmitted via the flat ribbon cable:
Pin 1 GND
Pin 4 +5V
3.2 Power board A1
The power board is an combination of:
• Control panel
• Voltage supply
• Motor-control
The power board carries out the following tasks:
• Power supply 15 V, DC for imbalance switch
• Power supply 5 V, DC for control panel and speed sensor
• Plugging station of the motor
• Control of the motor with triac phase-angle control
• Monitoring of the motor current.
• Braking of the motor with brake resistor
• Plugging station of the imbalance switch (only with EBA 20 C)
• Evaluation of the imbalance switch (only with EBA 20 C)
• Plugging station of the lid lock
• Control of the lid lock magnet at stand still of the rotor.
• Evaluation of the lid lock signal (lid open or closed).
• Communication with the control panel via TTL interface
• Error evaluation.
3.3 Motor M1
• The motor is connected via a plug to the power board.
• The motor is a collector-motor with carbon brushes.
• The motor is controlled by the power board.

8/31
3.4 Lid lock Y1
• Opening of the lid lock is prevented by a latch. The lid lock can only be opened when
the relay REL 602 on the power board is energised. This occurs when the rotor is at
standstill, mains power is applied and the key is pressed. The solenoid is ener-
gized for three seconds and releases the latch.
• The centrifuge can only be started when the lid is closed. A microswitch on the lid
lock detects the position of the lid lock (open/closed) and report it to the power
board.
3.5 Imbalance switch S2 (only with EBA 20 C)
• A microswitch (break contact) detects any imbalance.
• Imbalance can only be detected in running mode (starting, centrifuging and braking).
• If any imbalance is detected, the drive is changed over to braking.
4 Troubleshooting procedures
• Fuses in installation in which centrifuge is installed are intact.
• Mains input fuses of centrifuge are intact.
• Supply voltage present at (see circuit diagram):
− Connecting cable
− Appliance plug
− Mains switch
− Power board A1, plug ST1.1 (L) and ST1.2 (N)
• Look for the displayed error code in the chapter "Error messages".
• Remedy the error according to the instructions.
• Carry out a functional check after every repair and whenever a component is
replaced, see chapter "Functional check after a repair".

9/31
5 Error messages
The error message will be indicated in the speed display of the front panel
e.g. :
RPM x 100
t
START
STOP
5.1 MAINS RESET
• Switch off the mains switch.
• Wait at least for 10 seconds and then switch on the mains switch again.
5.2 Brief description
Display. Fault Brief description Page
- 1 - Tacho error Tacho pulses break down 10
- 2 - System reset Mains interrupt 10
- 3 - Imbalance Imbalance on the motor axis 10
- 4 - Communication Communication error 11
- 5 - Overload Fault in the motor or the motor control 11
- 7 - Overspeed Fault in the power board 11
Versions Error Wrong machine version setting 12
- d - Lid lock error Fault in lid lock system 12

10/31
5.3 Description and elimination of errors
– 1 – Tacho error
Error Speed sensor pulses (tacho) break down.
Error
consequence Drive switch off and brakes with the adjusted brake level.
Error cause • Carbon brushes worn out.
• Speed sensor (tacho) defective.
• Power board (A1) defective.
• Loosen contact in plug ST5.
Measurement 1. power board A1 / ST5 between pin 2 (GND) and pin 3 (+5V)
2. power board A1 / ST5 between pin 1 and pin 2 (GND)
(pulses: 0V, 5V, 0V, 5V etc. / 6 pulses per revolution)
See also section 11.2.2.
Error code reset Wait for a time duration of 100 sec. After this perform a MAINS
RESET.
– 2 – System reset
Error Mains interrupt during a run
Error
consequence Drive switch off and brakes with the adjusted brake level.
Error cause • Power supply has failed.
• Loosen contact in mains lead, appliance plug or the internal
electrical wires.
Error code reset 1. Wait for rotor standstill.
2. Open the lid and press key
START
or perform a MAINS RESET.
– 3 – Imbalance
Error Imbalance on motor axle
Error
consequence Drive switch off and brakes with the adjusted brake level.
Error cause EBA 20:
• Plug ST6 is unplugged or has loose contact.
• Power board (A1) is defective.
EBA 20 C:
• Weight difference in rotor components.
• Imbalance switch is defective or not connected.
• Imbalance switch is disadjusted (Adjustment see section
"Imbalance switch-off (only with EBA 20 C)").
• Loose contact in cable or plug ST6.
• Power board (A1) is defective.

11/31
Measurement Imbalance switch, plug ST6 pin 1 to Pin 4.
Switch is an opener. See also section 11.2.4.
Error code reset Open the lid after standstill
– 4 – Communication
Error Communication error between control board (A3) and power
board (A1).
Error
consequence Drive switches off and rotor runs down unbraked.
Error cause • Loose contact in flat ribbon cable.
• Control board (A3) defective.
• Power board (A1) defective.
Error code reset MAINS RESET after standstill.
If the MAINS RESET is performed before the rotor has standstill,
the set speed and the rotation will be indicated in the display until
the rotor has standstill.
– 5 – Overload
Error Power board detects overload.
Error
consequence Drive switches off and rotor runs down unbraked.
Error cause • Power board (A1) defective.
• Motor defective (windings or bearings)
Measurement Measure motor coils, see section 11.2.1.
Error code reset Perform a MAINS RESET after standstill
– 7 – Overspeed
Error System recognises excess speed.
Error
consequence Drive switches off and rotor runs down unbraked.
Error cause • Power board (A1) defective.
Error code reset Perform a MAINS RESET after standstill.

12/31
– d – Lid lock error
Error Lid lock is open during centrifugation.
Error
consequence Drive switches off and rotor runs down unbraked.
Error cause • Microswitch at lid lock is defective.
• Power board (A1) defective.
• Loosen contact in Plug ST4 at pin 5 and pin 6.
• Mechanical defect at the lid lock.
• Emergency release was executed during centrifugation.
Measurement Remove plug ST4 and measure between pin 5 and pin 6:
Lid opened : ≈0 Ω
Lid closed: ∞Ω
See also section 11.2.3.
Error code reset Perform a MAINS RESET after standstill.
5.4 Defects without Error indications.
No speed indication / Machine-Version-Error
Error After switching on the centrifuge the speed indicator extinguish and
in the time indicator appears the set machine version.
Error cause • Wrong machine version adjusted.
Example for indication
RPM x 100 t
START
STOP
Proceed as the followings: 1. Set the correct machine version with
the keys beneath the time
indicator.
EBA 20 = 1
EBA 20 C = 5
2. Press the key
STOP
in order to store
the set machine version.
3. Perform an MAINS RESET.

13/31
The lid can not be opened
Error The lid can not be opened.
The rotation display shows (lid open).
Error cause • Microswitch at lid lock is defective
• Loosen contact on plug ST4 / pin 5 and pin 6
• Power board (A1) or control panel (A3) defective
Measurement Remove plug ST4 and measure on the plug between pin 5 and
pin 6:
Switch closed: ≈0 Ω
Switch: open ∞Ω
See also section 11.2.3.
Opening the lid Release the lid by using the emergency release.
The lid can not be opened
Error The lid can not be opened.
The rotation display shows (lid closed).
Error cause • Solenoid on lid lock is defective
• Loosen contact on plug ST4 / pin 1 and pin 3
• Power board (A1) or control panel (A3) defective
Measurement Remove plug ST4 and measure on the plug between pin 1 and
pin 3. See also section 11.2.3.
Opening the lid Release the lid by using the emergency release.
No display
Error No power supply on control board (A3)
Error
consequence No operation possible
Error cause • No mains supply
• Power board (A1) defective
• Control board (A3) defective
• Interruption in the flat ribbon cable between power board (A1)
and control board (A3)
Measurement 1. Mains supply, power board A1, plug ST1.2 (L) to ST1.1 (N)
2. Power board A1, plug ST3 pin 4 (+5V) to pin 1 (GND)
3. Control board A3, plug ST1 pin 4 (+5V) to pin 1 (GND)

14/31
6 Settings and enquiries
6.1 Setting the machine version
The machine version stored in the control panel must correspond to the centrifuge
model. Control panels supplied as spare part are set to machine version 4 (ROTOFIX
32).
After installing the control panel the EBA 20 must be set to machine version 1 and the
EBA 20 C to machine version 5.
If another machine version than 1 or 5 is set in the control panel, the set machine
version will appear in the display after switching on the centrifuge.
Now the correct machine version has to be set as follows:
1. Set the correct machine version for
EBA 20 or EBA 20 C by using the
and keys beneath the time
indicator.
RPM x 100 t
START
STOP
2. Press the key
STOP
in order to store the set machine version.

15/31
6.2 Enquiry the machine version
The enquiry of the machine version is only possible if the rotor is at standstill.
1. Switch off the mains switch.
2. Keep the key beneath the speed display and the key pressed simultaneously.
3. Switch on the mains switch and release the keys again.
The speed indicator shows the machine version and the time indicator shows the set
brake step: e.g.:
EBA 20:
RPM x 100 t
START
STOP
RPM x 100 t
START
STOP
EBA 20 C:
RPM x 100 t
START
STOP
RPM x 100 t
START
STOP
If the machine version and brake step are not displayed, press the key under the
speed indicator until they are displayed.
4. To exit the machine version display press the key
STOP
or perform a MAINS-
RESET.

16/31
6.3 Enquiry the programme versions
The enquiry of the programme versions is only possible if the rotor is at
standstill.
1. Switch off the mains switch.
2. Keep the key beneath the speed display and the key pressed simultaneously.
3. Switch on the mains switch and release the keys again.
The speed indicator shows the machine version and the time indicator shows the set
brake step.
EBA 20:
RPM x 100 t
START
STOP
RPM x 100 t
START
STOP
EBA 20 C:
RPM x 100 t
START
STOP
RPM x 100 t
START
STOP
4. Press the key beneath the speed indicator so often until the programme version of
the control panel (e.g. b1.12) is displayed.
RPM x 100 t
START
STOP
5. Press the key beneath the speed indicator again.
The programme version of the power board (e.g. C1.03) is displayed.
RPM x 100 t
START
STOP
6. To exit the programme versions display press the key
STOP
or perform a MAINS-
RESET

17/31
6.4 Setting the brake step
The setting of the brake step is only possible if the rotor is at standstill.
1. Switch off the mains switch.
2. Keep the key beneath the speed display and the key pressed simultaneously.
3. Switch on the mains switch and release the keys again.
The speed indicator shows the machine version and the time indicator shows the set
brake step: e.g.:
EBA 20:
RPM x 100 t
START
STOP
RPM x 100 t
START
STOP
EBA 20 C:
RPM x 100 t
START
STOP
RPM x 100 t
START
STOP
If the machine version and brake step are not displayed, press the key under the
speed indicator until they are displayed.
4. Set the desired brake step with the keys beneath the time display.
Step 1 = short run-down time, Step 0 = long run-down time.
For run-down times, see chapter "Anhang/Appendix, Rotor und Zubehör/Rotor and
accessories" in the operating instructions.
5. Press the key
STOP
to save the setting.

18/31
6.5 Locking the input of the speed, time and brake step and locking the key
(only with EBA 20 C)
Locking of the key and locking of the input of the speed, time and brake step
is only possible with machines with machine version 5 (EBA 20 C) and a
programme version of the control panel from b1.40.
The activation and deactivation of the lock is only possible if the rotor is at
standstill.
1. Switch off the mains switch.
2. Keep the key beneath the speed display and the key pressed simultaneously.
3. Switch on the mains switch and release the keys again.
The speed indicator shows the machine version and the time indicator shows the set
brake step:
RPM x 100 t
START
STOP
RPM x 100 t
START
STOP
If the machine version and brake step are not displayed, press the key under the
speed indicator until they are displayed.
4. Keep the key
START
pressed and then press the key beneath the speed indicator.
In the speed indicator the letter "c" is displayed, this means that the input of the
speed, time and brake step is now locked and the keys and are deactivated.
RPM x 100 t
START
STOP
RPM x 100 t
START
STOP
To deactivate the lock also keep the key
START
pressed and then press the key
beneath the speed display.
5. Press the key
STOP
to save the setting.
6.6 Lid lock control
The lid can be opened when the rotor is at standstill and the key is pressed. The
solenoid on the lid lock remains energized for three seconds.

19/31
6.7 Imbalance switch-off (only with EBA 20 C)
The permissible imbalance is specified for rotor E1824 by the indication of the
difference in weight of opposite rotor positions.
When having a difference in weight within the range of 6g to 12g during run-up, the
drive has to switch off before reaching 1500 RPM.
The imbalance switch-off is adjusted by changing the distance of the imbalance switch.
With a test run with the indicated differences in weight the imbalance switch-off will be
checked.
Adjusting the imbalance switch:
• Loosen both screws at the angle bracket of the imbalance switch on the outer part of
the housing floor until you can shift it.
• Set the permissible imbalance by shifting the angle bracket.
• Tighten both screws at the angle bracket of the imbalance switch again.
• Check the imbalance switch-off with a test run.
7 Change mains input fuse
Switch off the mains switch and separate the centrifuge from the mains!
The fuse holder (A) with the mains input fuses is located next to
the mains switch.
• Remove the connecting cable from the machine plug socket.
• Press the snap-fit (B) against the fuse holder (A) and
remove.
• Exchange defective mains input fuses.
AB
Only use fuses with the rating defined for the type.
See the following table.
• Reinsert the fuse holder until the snap-fit clicks shut.
• Reconnect the centrifuge to the mains supply.
Model Type Fuse Order no.
EBA 20 2002
EBA 20 C 2002-C T 1,6 AH/250V E891
EBA 20 2002-01
EBA 20 C 2002-01C T 3,15 AH/250V E997

20/31
8 Functional check after a repair
After a repair a functional check of the unit must be carried out. For functional check a
test run with the loaded rotor must be performed.
During the test run the followings must be checked:
• Function of the keys and the display.
• Run-up and slow-down time, max. speed of the rotor. Values see operating
instructions chapter "Anhang/Appendix, Rotoren und Zubehör/Rotors and
accessories".
• Sample temperature. Values see operating instructions chapter "Anhang/Appendix,
Rotoren und Zubehör/Rotors and accessories".
• Imbalance switch-off (only with EBA 20 C). Values see chapter "Imbalance switch-
off (only with EBA 20 C)".
• Current consumption. Values see chapter "Technical specification".
After the test run a safety test must be carried out. Check the following values:
• Insulation resistance > 2 MΩ
• Protective conductor resistance < 0.2 Ω
• Leakage current < 3.5 mA *
* limit according to EN 61010-1
A laboratory centrifuge do not belong to those medical appliances which may be tested
according to the regulation IEC 60601-1 or corresponding national medical electronic
standards. Laboratory centrifuges are classified as laboratory equipment.
The regulations applying to laboratory equipment are IEC 61010-1 or European
standard EN 61010-1.