Hettich EBA-20S Service manual
EBA 20S
03.08 Andreas Hettich GmbH & Co. KG AR2080EN
Repair instructions
Andreas Hettich GmbH & Co. KG
Föhrenstraße 12, D-78532 Tuttlingen / Germany
Phone (07461) 705-0
Fax (07461) 705-125
info@hettichlab.com, service@hettichlab.com
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.
Änderungen vorbehalten!
AR2080EN / 03.08
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Contents
1 Introduction ..............................................................................................................5
2 Symbol meanings.....................................................................................................5
3 Description of the centrifuge.....................................................................................6
3.1 Control panel A3 ...............................................................................................7
3.2 Power board A1 ................................................................................................7
3.3 Motor M1...........................................................................................................8
3.4 Speed sensor B3...............................................................................................8
3.5 Brake resistor R1 and Overtemperature fuse F3...............................................8
3.6 Lid lock Y1 ........................................................................................................8
3.7 Imbalance switch S 2........................................................................................8
4 Troubleshooting procedures.....................................................................................9
5 Error messages......................................................................................................10
5.1 MAINS RESET................................................................................................10
5.2 Brief description ..............................................................................................10
5.3 Description and elimination of errors...............................................................11
5.4 Defects without Error indications.....................................................................16
6 Settings and enquiries............................................................................................18
6.1 Setting the machine version............................................................................18
6.2 Enquiry the machine version...........................................................................19
6.3 Enquiry the programme versions ....................................................................20
6.4 Brake adjustment............................................................................................20
6.5 Lid lock control................................................................................................21
6.6 Imbalance switch-off .......................................................................................21
7 Change mains input fuse........................................................................................22
8 Functional check after a repair...............................................................................22
9 Assembling and disassembling components..........................................................23
9.1 Motor M1 / speed sensor B3 / Rubber-metal bearing......................................24
9.2 Power board A1 ..............................................................................................24
9.3 Control panel A3 ............................................................................................24
9.4 Brake resistor R1 ............................................................................................25
9.5 Overtemperature fuse F3................................................................................25
9.6 Flat ribbon cable..............................................................................................25
9.7 Appliance plug with mains switch....................................................................25
9.8 Imbalance switch S2.......................................................................................25
9.9 Lid lock Y1 ......................................................................................................25
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10 Circuit diagrams .................................................................................................26
10.1 Circuit diagram and plug assignment..............................................................27
10.2 Signals and test results................................................................................... 28
10.2.1 Speed sensor B3 (Tacho)........................................................................28
10.2.2 Motor ....................................................................................................... 28
10.2.3 Brake resistor R1 and overtemperature fuse F3......................................29
10.2.4 Lid lock Y1............................................................................................... 29
10.2.5 Imbalance switch..................................................................................... 30
10.2.6 Intermediate voltage on power board A1................................................. 30
11 Technical specification....................................................................................... 31
12 Skeleton construction of EBA 20S...................................................................... 32
13 Index .................................................................................................................. 33
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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.
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3 Description of the centrifuge
The EBA 20S is a microprocessor-controlled centrifuge which is comprised of the
following electrical components:
• Control panel
• Power board
• Motor
• Speed sensor (Tacho)
• Brake resistor with overtemperature fuse
• Lid lock system
• Imbalance switch
All electronic components are on mains, due to the DC-coupling
Steuerteil LED / Control panel LED
Netz / Mains
Verschluß / Lid lock
Deckelschalter
Lid switch
Uwuchtschalter
Imbalance switch
Bremswiderstand
Brake resistor
Drehzahlsensor (Tacho)
Speed sensor (tacho)
EEPROMSchnittstelle / Interface
Leistungsteil
Power board
mit Mikroprozessorsteuerung
und Frequenzumrichterteil
With Micoprocessor control
and frequency control
Motor
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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
• Frequency converter
The power board carries out the following tasks:
• Power supply 15 V, DC for imbalance switch
• Power supply 5 V, DC for control panel
• Generating the motor power supply.
(three-phase current with variable frequency and voltage)
Functional description: The mains supply is rectified, smoothened and chopped
into a pulse width pattern in three bridge elements with a
microprocessor.
• Slot for motor with integrated overtemperature switch
• Monitoring the motor current
• Evaluating the overtemperature switch in the motor
• Slot for imbalance switch
• Evaluating the imbalance switch
• Slot for brake resistor
• Triggering the brake resistor
• Slot for speed sensor
• Evaluating the speed sensor pulses (2 pulses per revolution)
• Slot for lid lock
• Triggering the lid lock magnet at standstill of the rotor
• Evaluating the message line lid lock open/closed
• Communication with the control panel via TTL interface
• Error evaluation
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3.3 Motor M1
• The motor is a three- phase asynchronous motor with two pairs of poles.
• The motor is protected against overheating by an overtemperature switch.
• The power board evaluates the overtemperature switch.
• The motor is controlled by the power board with a three-phase current with variable
frequency and voltage.
3.4 Speed sensor B3
• The speed sensor (speedometer) is located at the bottom of the motor.
• The speed signal (2 pulses per revolution) will be triggered by two magnets fixed at
the motor axle.
• The speed of the rotor is monitored and controlled by the power board.
3.5 Brake resistor R1 and Overtemperature fuse F3
• The braking copper which is integrated on the power board transfers the electrical
energy produced during braking, from a voltage of 380 V with the 230 V version and
203 V with the 120 V version, to the brake resistor in a controlled manner.
• An overtemperature fuse protects the brake resistor against overheating. When the
overtemperature fuse (F3) blows, the power board will be separated from the power
supply.
3.6 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
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.
3.7 Imbalance switch S 2
• A switch 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.
is pressed. The solenoid is ener-
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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 S402L and S402N
• 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".
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5 Error messages
The error message will be indicated in the speed display of the front panel
e.g. :
START
RPM x 100
t
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 during the run 11
- 2 - System reset Mains interrupt 11
- 3 - Imbalance Imbalance on the motor axis 11
- 4 - Communication Communication error 12
- 5 - Overload Fault in the motor or the motor control 12
- 6 - Overvoltage Mains is out of the tolerance 13
- 7 - Overspeed Overspeed detected 13
- 8 - Undervoltage Mains is out of the tolerance 13
- 9 - Overtemperature Overtemperature switch in the motor release 14
Versions Error No indication in the speed display
Wrong machine version setting
- c - Controller-Watchdog Fault in power board 14
- d - Lid lock error Fault in lid lock system 15
- E - Short circuit Short circuit in power board 15
- F - No Rotor code Wrong machine version 15
16
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5.3 Description and elimination of errors
– 1 – Tacho error
Error Tacho pulses break down during the run.
Error
Drive switch off and brakes with the adjusted brake level.
consequence
Error cause
• Speed sensor (tacho) defective
• Power board (A1) defective
• Loosen contact in plug S502
Measurement 1. A1 / S502 pin 2 (GND) to pin 3 (+UB)
2. Speed sensor plug S502 , pin 4 – pin 2 GND (2 pulses per
revolution). See also section 10.2
Error code reset Wait for a time duration of 120 sec. and after this perform a MAINS
RESET.
– 2 – System reset
Error Mains interrupt during a run
Error
Drive switch off and brakes with the adjusted brake level.
consequence
Error cause
• Power supply has failed
• Loosen contact in electrical connections
Error code reset 1. Wait for rotor standstill
2. Open the lid and press key
or
perform a MAINS RESET
ST ART
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