Hettich Mikro22 Service manual

Repair instructions

MIKRO 22 / 22 R

© 02.04 AR025GB

Phone: [phone] • Fax: [phone] • Internet: www.hettichlab.com • e-mail: [e-mail], [e-mail]

Andreas Hettich GmbH & Co. KG • Gartenstraße 100 • D-78532 Tuttlingen • Germany

TABLE OF CONTENTS

1. INTRODUCTION...................................................................................................... 6

2. DESCRIPTION OF THE NEW HETTICH CENTRIFUGES ...................................... 7

2.1. Functional structure of the Mikro 22 / 22 R ...................................................... 7

2.2. Control panel (CP) ........................................................................................... 7

2.3. Supply board (SB) A1 ...................................................................................... 8

2.4. Frequency converter (FC) A2 .......................................................................... 8

2.5. Special features ............................................................................................... 9

2.6. Motor / Tacho system ...................................................................................... 9

2.7. Imbalance switch ........................................................................................... 10

2.8. Interlocking .................................................................................................... 10

2.9. Cooling........................................................................................................... 10

2.9.1. Temperature sensor B1 in the centrifuge chamber ................................. 10

2.9.2. Function of the cooling board (CB) A3 .................................................... 10

2.10. Fan................................................................................................................. 10

2.11. Offset calibration............................................................................................ 11

2.12. Protection....................................................................................................... 11

3. REQUIREMENTS FOR ERROR IDENTIFICATION .............................................. 12

3.1. Correct power supply..................................................................................... 12

3.2. Functional check............................................................................................ 12

3.3. Procedure for diagnosing errors .................................................................... 12

4. ERROR MESSAGES ............................................................................................. 13

4.1. Brief description ............................................................................................. 13

4.2. Description and elimination of errors.............................................................. 15

5. FACTORY SETTING ............................................................................................. 23

5.1. Control panel ................................................................................................. 23

5.2. Procedure for initialisation.............................................................................. 23

5.3. Imbalance Mode ............................................................................................ 24

5.4. OFFSET alignment ........................................................................................ 24

5.4.1. OFFSET value ........................................................................................ 25

5.4.2. Procedure for performing an OFFSET alignment.................................... 25

5.4.3. Note for temperature sensor in centrifuge chamber................................ 25

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6. FUNCTION RETRIEVALS / SETTINGS................................................................. 26

6.1. Acoustic signal ............................................................................................... 26

6.2. Hours of operation.......................................................................................... 26

6.3. Slippage of the drive ...................................................................................... 27

6.4. Setting display contrast on control panel........................................................ 27

7. FUNCTIONAL CHECK........................................................................................... 28

7.1. Functional check at factory............................................................................. 28

8. FUNCTIONAL TEST .............................................................................................. 30

8.1. Checking the proper working order ................................................................ 30

8.2. Proper working order after repairs.................................................................. 30

9. ASSEMBLING AND DISASSEMBLING COMPONENTS...................................... 30

9.1. Speed sensor B3 (speedometer) ...................................................................33

9.2. Motor M1 / Vibration damper.......................................................................... 33

9.3. FC (frequency converter) ............................................................................... 33

9.4. SB (supply board) A1 ..................................................................................... 33

9.5. CB A3 (cooling board) only MIKRO 22 R ....................................................... 33

9.6. CP (control panel) A4..................................................................................... 34

9.7. EPROM at CP................................................................................................34

9.8. CC (control cables) ........................................................................................ 34

9.9. LL (Y1) (lid locking) ........................................................................................ 34

9.10. BR R1 (brake resistor) ................................................................................... 34

9.11. Radio interference suppression filter Z1......................................................... 34

9.12. Mains choke coil (L1) .....................................................................................34

9.12.1. Assembly and disassembly ..................................................................... 34

9.12.2. Short the mains choke coil ......................................................................35

9.13. Mains switch Q1............................................................................................. 35

9.14. Appliance plug B4, overvoltage protection F1 ................................................ 36

9.15. Imbalance switch S1 ......................................................................................36

9.16. Temperature sensor B1 in centrifuge chamber .............................................. 36

9.17. Temperature sensor B2 at condenser............................................................36

9.18. Fan M3........................................................................................................... 36

9.19. Compressor M2.............................................................................................. 36

9.20. Lid spring........................................................................................................ 37

9.21. Hinge block .................................................................................................... 37

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10. SPEEDOMETER-CODE-POSITION OF THE ROTORS .................................... 38

11. CIRCUIT DIAGRAMS......................................................................................... 40

11.1. Mains supply with supply board (SB) 230 V................................................... 40

11.2. Mains supply with supply board (SB) 115 V................................................... 41

11.3. Circuit diagram supply board (SB) ................................................................. 42

11.4. Connecting diagram and component layout supply board (SB) ..................... 43

11.5. Signals at control cable (between CP-SB) ..................................................... 45

11.6. Block diagram control panel (CP) .................................................................. 46

11.7. Connecting diagram Control board (CP)........................................................ 47

11.8. Block diagram and signals at frequency converter (FC) ................................ 48

11.9. Connecting diagram frequency converter (FC) .............................................. 51

11.10. Circuit diagram cooling board..................................................................... 52

11.11. Connecting diagram and component layout cooling board......................... 54

12. TECHNICAL SPECIFICATIONS ........................................................................ 57

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Abbreviations

CP Control panel
FC Frequency converter
SB Supply board
CB Cooling board
CC Control cable

LL Lid locking
BC Braking chopper
BR Brake resistor

MR Mains reset

EC Error cause
ES Error consequence
ER Error remedy

ECR Error-code reset

Mains switch OFF - ON

M Measurement

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1. Introduction

• This repair instruction is only intended for specialized staff authorized by HETTICH.

Interventions and modifications at centrifuges, which have been conducted
by persons not authorized by HETTICH, 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 HETTICH expire.

• The aim of these repair instructions is to enable any errors to be located and

eliminated quickly.

There should be no interventions at, or replacement of components on the
individual electronics boards. Experience shows that if an intervention is not
performed in accordance with regulations, or if a component is installed
whose specification is not identical to that of the original component, then the
error (defect) which has occurred will be compounded by further damage. In
such an event any guarantee claim or liability claim against the HETTICH
ceases to exist.
Any electronics boards which are not repaired in accordance with the
regulations cannot be acknowledged as being replacement spare parts.

• Information about the operation of the centrifuge please see operating instructions.

• We reserve all rights for these technical documents.

• Technical alterations reserved.

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2. Description of the new Hettich centrifuges

2.1. Functional structure of the Mikro 22 / 22 R

These microprocessor-controlled centrifuges are comprised of the following electrical
components:

• Control panel (CP), microprocessor-controlled

• Supply board (SB)

• Frequency converter (FC, motor control), microprocessor-controlled

• Motor with speed sensor (speedometer)

• Braking chopper (BC) with brake resistor (BR)

• Lid locking (LL)

• Cooling board (CB), only Mikro 22 R

2.2. Control panel (CP)

The CP is the ”brain” or ”master” of the centrifuge.
Via a serial data bus system, the MASTER controls its SLAVE, the component:

− frequency converter (FC)

The individual tasks of the CP are:

• Management of operator inputs and control of LCD display

• Storage of 3 run programs

• Control of components:

− FC via the enabling circuit and via the serial interface

− cooling and fan

• Evaluation of the speed sensor (speedometer)

• Evaluation of the imbalance switch.

• Evaluation of the FC fault alarm circuit

• Evaluation of the LL open/closed signalling circuit

• Control of the relay for the LL solenoid at rotor standstill

• Temperature measurement and sensor evaluation of the temperature sensor in

centrifuge chamber (only refrigerated centrifuge).

• Routine for input, storage and transfer of temperature offset values

• Format of the serial interface:

5 Volt interface with 3 conductors
(16-pole control cable, pole 6, 8 and 11)

• The CP is powered from the SB via the control cable:
+ 10...15 Volt pole 1,2
GND pole 15,16

CP : control panel, FC : frequency converter, SB : supply board, CB : cooling board, CC : control cable, LL : lid locking, BC : braking chopper,

BR : brake resistor, MR : mains reset, EC : error cause, ES : error consequence, ER : error remedy, M : measurements, ECR : error-code reset

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2.3. Supply board (SB) A1

The SB performs the following individual functions:

• 12 V DC and 5 V DC supply for the SB.

• 12 V DC supply for the CP.

• 12 V DC supply for the CB (only Mikro 22 R).

• Plugging station X5 for mains power supply, LL magnet and transmission of the

signalling circuit for LL switch (open/closed over opto-coupler to the CP).

• Power supply for speed sensor (speedometer).

• Plugging station X4 for speed sensor cable and transmission to the CP and FC.

• Control of the relay for the LL solenoid at rotor standstill

• Plugging station X3 for the imbalance switch and direct transmission of the imbalance

signal to the CP.

• The 5 Volt interface with 3 conductors is converted to an RS 485 interface with 2

conductors:

Interface to FC: RS 485-interface via 2 conductors -

• Transfer of primary enabling (=Hardware STOP) CP ⇒ FC

• Transfer of fault circuit (=FC-ERROR) FC ⇒ CP

2.4. Frequency converter (FC) A2

The FC performs the following individual functions:

• Generation of the motor power supply

(3-phase AC current of variable frequency and voltage)
Mode of operation: The mains supply is rectified, smoothed and chopped in three

bridge elements to give a pulse-duration modulated supply.

• Monitoring of the motor current

• Evaluation of the overtemperature switch in the motor (only version 115V, AC)

• Slave behaviour (handling of interrogations and commands from the CP via the serial

interface):

RS 485-interface with 2 conductors
(10-pole control cable, pole 3 and 5)

• Evaluation of the primary enabling (=Hardware STOP) for the FC

(10-pole control cable, pole 7)

• Evaluation of potential faults and monitoring of the fault circuit (=FC-Error)

(10-pole control cable, pole 4)

• The electrical power, which resulted from braking, will be conducted to the BR. The

braking chopper switches at a voltage:

- from approximately 390V (230V series)

- from approximately 200V (115V series)

• The BR is protected by an overtemperature switch. At a short circuit on the BC,

which is located on the FC, the BR overheats because of high current. The
overtemperature switch cuts off the voltage supply from the FC. After cooling down at
the BR the voltage supply is switched on again.

CP : control panel, FC : frequency converter, SB : supply board, CB : cooling board, CC : control cable, LL : lid locking, BC : braking chopper,

BR : brake resistor, MR : mains reset, EC : error cause, ES : error consequence, ER : error remedy, M : measurements, ECR : error-code reset

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• The CP issues the following via the serial interface:

− Speed

− Starting and braking levels

− Control commands START, BRAKE, STOP

• State display by LED´s:

In standby mode the green LED is on
In running mode the green LED is on
In fault mode the green LED flashes
If the FC processor detects a fault, it shuts down itself automatically and triggers the

fault circuit (FC-ERROR). The CP then interrogates the type of fault via the serial
interface.

2.5. Special features

• Multiprocessor concept:

Although one microprocessor will fail, the other one will continue to monitor its
assigned area.
If the CP fails, the drive will be shut down automatically by the FC when no inter­rogations have been received via the interface for more than 30 seconds.

• Interface concept:

Transmission of data is monitored by an extra check sum.

• Hardware concept:

All switches with a safety relevant function are of the NC-contact type, which
means that loose contacts and open-circuit faults can also be detected.

2.6. Motor / Tacho system

• The motor is a 3 phase asynchronous motor with 2 pairs of poles.

• A speed sensor (speedometer) attached to the motor receives the following from the

transmitter attached to the rotor,

− rotor code information (see section 10) and

− speed data (6 pulses per revolution)

• The ACTUAL speed is monitored and controlled via the CP

− Double safety:

The FC is also programmed that no value of speed

in excess of the maximum permitted rotor speed

can be selected. The FC monitors the speed and

switches off at excess speed with error code

“ERROR 84”.

• Rotor standstill is monitored via the CP.

− The lid can only be opened when the CP has detected standstill.

CP : control panel, FC : frequency converter, SB : supply board, CB : cooling board, CC : control cable, LL : lid locking, BC : braking chopper,

BR : brake resistor, MR : mains reset, EC : error cause, ES : error consequence, ER : error remedy, M : measurements, ECR : error-code reset

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2.7. Imbalance switch

• 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.

2.8. Interlocking

• Opening of the LL is prevented by a latch. The LL can only be opened when the relay

on the SB is energized by the CP. This occurs when the rotor is at standstill and
mains power is applied. A solenoid is energized and releases the latch.

• The centrifuge can only be started when the lid is closed. A microswitch on the LL

detects the position of the LL.

2.9. Cooling

• Temperature behaviour:

− When rotor is at standstill and the lid is locked, the cooling is operating.

− When rotor is at standstill and the lid is unlocked, there is no cooling.

2.9.1. Temperature sensor B1 in the centrifuge chamber

• This temperature is processed in the CP.

• The housing of the temperature sensor B1 also contains an overtemperature switch.

In refrigerated centrifuges this switch cuts off the drive at > 60°C.

2.9.2. Function of the cooling board (CB) A3

• Plugging station (X3) for the temperature sensor and the overtemperature switch in

the centrifuge chamber.

• The voltage of the temperature sensor in the centrifuge chamber plug X4 being

transmitted over a 10-pole CC to the CP plug X101.

• The signal of the overtemperature switch in the centrifuge chamber plug X4 being

onward transmitted over a 10-pole CC to the CP plug X101.

• Plugging station (X2) for the overheating protection B2 at the condenser.

• Relay circuit for the compressor and the fan. The overheating protection B2 at the

condenser is series connected to the relay voltage.

• Plugging station (X1) for the compressor and the fan.

2.10. Fan

• The fan cools down the refrigerant flowing through the condenser.

• The fan is parallel-connected to the compressor.

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CP : control panel, FC : frequency converter, SB : supply board, CB : cooling board, CC : control cable, LL : lid locking, BC : braking chopper,

BR : brake resistor, MR : mains reset, EC : error cause, ES : error consequence, ER : error remedy, M : measurements, ECR : error-code reset

2.11. Offset calibration

• Offset calibration is performed in order to equalize the tolerances of the temperature

sensor and the electronics.

Perform Offset calibration
when replacing:

− the temperature sensor

− the CP

− the CP-EPROM

2.12. Protection

Mains power input
Mains switch
FC
Motor

Cooling

Where/How

calibrate the temperature sensor.
calibrate temperature sensor and read out the
old offset values and put them in the new CP.
Read out the old offset values and put them in the

new CP.

⇒
⇒
⇒
⇒

Mains input with overvoltage protection.
Thermal overload protection (fuse).
Electronic protection.
Overtemperature cutout > 135°C (only 115V

version).

⇒

Overtemperature switch in centrifuge chamber and
at condenser.

CP : control panel, FC : frequency converter, SB : supply board, CB : cooling board, CC : control cable, LL : lid locking, BC : braking chopper,

BR : brake resistor, MR : mains reset, EC : error cause, ES : error consequence, ER : error remedy, M : measurements, ECR : error-code reset

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3. Requirements for error identification

3.1. Correct power supply

• All fuses of house installation are intact.

Mains voltage is present on the following circuits:

• Cable leading to mains cable

• Appliance plug

• Mains switch

• Radio interference suppression filter

• Supply board A1 (SB), plug X5, (PIN 1 and PIN 5)

3.2. Functional check

• Mains switch is ON.

• All LED`s on control panel must light up.

• The centrifuge type and the software version number appears in the display.

• After about 8 sec. the display switches over to

− the most recently used centrifuging data or

− the error code.

3.3. Procedure for diagnosing errors

• Look for the displayed error code in the chapter 4 "Error messages".

• Remedy the error according to the instructions.

• Carry out a functional check after every repair and whenever a component is

replaced.

• The technical data which were determined during the final check can be found in the

chapter 7 "Functional check".

12/51

CP : control panel, FC : frequency converter, SB : supply board, CB : cooling board, CC : control cable, LL : lid locking, BC : braking chopper,

BR : brake resistor, MR : mains reset, EC : error cause, ES : error consequence, ER : error remedy, M : measurements, ECR : error-code reset

4. Error messages

4.1. Brief description

• Error messages in:

MIKRO 22

MIKRO 22 R

Error designation No. Brief description Page

TACHO-ERROR 01 Speedometer pulses break down during rotation 15
TACHO-ERROR 02 No speedometer pulses after start command 15

IMBALANCE Imbalance on motor axle 16

CONTROL-ERROR 04 LL error, lid opened without recognizing that

16

motor had stopped

N > MAX 05 Excessive speed error, 250 RPM above n-max of

16

rotor

ROTORCODE 10 Invalid rotor code 17

MAINS INTERRUPT Mains interruption 17

VERSION-ERROR 12 Error in initialisation 17

N < MIN 13 Speed error, slippage is too great 18

CONTROL-ERROR 21 CP - error: speed 18
CONTROL-ERROR 22 CP - error: I²C bus 18
CONTROL-ERROR 23 CP - error: display memory 18
CONTROL-ERROR 24 CP - error: clock timeout 18
CONTROL-ERROR 25 CP - error: EEPROM 18
CONTROL-ERROR 26 CP - error: driver defective 18

N > ROTOR-MAX --- CP - error: nominal speed is higher

than permitted rotor speed

18

or nominal RCF is higher
than permitted rotor RCF

SER I/O-ERROR 30 No connection between CP and serial interface 18
SER I/O-ERROR 31 No connection between FC and serial interface 18
SER I/O-ERROR 33 Subassembly data incorrectly transmitted 19
SER I/O-ERROR 34 Data incorrectly transmitted between CP and FC 19
SER I/O-ERROR 36 No acknowledgement (NAK) from FC to CP 19

CP : control panel, FC : frequency converter, SB : supply board, CB : cooling board, CC : control cable, LL : lid locking, BC : braking chopper,

BR : brake resistor, MR : mains reset, EC : error cause, ES : error consequence, ER : error remedy, M : measurements, ECR : error-code reset

13/51

Error designation No. Brief description Page

No cooling

Overtemperature at condenser 19

(No error displayed)

°C / *-ERROR

52 Overtemperature in centrifuge chamber 20

°C / *-ERROR 53 Temperature sensor in centrifuge chamber is

defective

FU/CCI-ERROR 60 Faulty release signal to FC 20
FU/CCI-ERROR 61 FC - error: computing section 21
FU/CCI-ERROR 62 FC - error: undervoltage 21
FU/CCI-ERROR 63 FC - error: overcurrent 21
FU/CCI-ERROR 64 FC - error: overvoltage 21
FU/CCI-ERROR 67 FC - error: overtemperature in motor

(only 115V)
FU/CCI-ERROR 68 FC - error: overtemperature in FC 22
FU/CCI-ERROR 69 FC - error: EEPROM 22
FU/CCI-ERROR 84 FC - error: FC recognizes excess speed 22
FU/CCI-ERROR 85 FC - error: “Watchdog”in FC had

Triggered

20

22

22

14/51

CP : control panel, FC : frequency converter, SB : supply board, CB : cooling board, CC : control cable, LL : lid locking, BC : braking chopper,

BR : brake resistor, MR : mains reset, EC : error cause, ES : error consequence, ER : error remedy, M : measurements, ECR : error-code reset

4.2. Description and elimination of errors

TACHO - ERROR 01

EC During centrifugation the speedometer pulses are interrupted.
ES The rotor slows down until it stops.

After the rotor stops, there is a DC braking for 30 sec.
An MR during slowing-down causes a DC braking for 3 min.
After the DC braking, the ”open the lid” release takes place.
Further cooling to NOMINAL temperature.

ER

• Speed sensor (speedometer) defective or loose contact on plug.

Measure speedometer pulses on plug X4 / SB, (pin 4 - pin 2).

• CC to CP, or CC to FC is defective.

• SB or CP or FC is defective.

M Also see at SB-X4, CP-X1 (PIN 14 and FC-S501 (PIN 8).

ECR Open the lid. Turn the rotor by hand and perform an MR while the

rotor is turning.

TACHO - ERROR 02

EC There are no speedometer pulses on the CP after startup.
ES The rotor slows down until it stops.

After the rotor stops, there is a DC braking for 30 sec.
An MR during slowing-down causes a DC braking for 3 min.
After the DC braking, the ”open the lid” release takes place.
Further cooling to NOMINAL temperature.

ER

• Startup took place without the rotor.

• Motor not connected.

• Motor is defective.

• Speed sensor (speedometer) defective, or loose contact on plug.

Measure speedometer pulses on plug X4 / SB, (pin 4 - pin 2).

• CC to CP, or CC to FC is defective.

• No release signal to FC.

• SB or CP or FC is defective.

M Also see at SB-X4, CP-X1 (PIN 14 and FC-S501 PIN 8).

ECR Open the lid. Turn the rotor by hand and perform an MR while the

rotor is turning.

CP : control panel, FC : frequency converter, SB : supply board, CB : cooling board, CC : control cable, LL : lid locking, BC : braking chopper,

BR : brake resistor, MR : mains reset, EC : error cause, ES : error consequence, ER : error remedy, M : measurements, ECR : error-code reset

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IMBALANCE

EC Imbalance on motor axle.
ES The centrifuge slows down until the “open the lid” release occurs.

Further cooling until NOMINAL temperature is reached.

ER

• Weight difference in rotor components.

• Supporting lugs not lubricated.

• False IMBALANCE MODE is set (see chapter "Imbalance Mode").

• Imbalance switch not connected.

• Imbalance switch is defective.

• Loose contact in cable or plug.

• CC to CP is defective.

• CP or SB is defective.

M Also see at SB-X3 and CP-X1 (PIN 12)

ECR Perform an MR.

CONTROL - ERROR 04

EC LL is open during centrifugation.
ES Slowing down until the ”open the lid” release occurs.

Further cooling until NOMINAL temperature is reached.

ER

• LL is defective and can be opened during centrifugation.

• Loose contact in cable or in plug.

• CC to CP is defective.

• CP or SB is defective.

M Also see at SB-X5 (PIN 2 and PIN 6) and CP-X1 (PIN 5).

ECR Perform an MR.

N > MAX 05

EC Excess speed. The speed recognized by the speed sensor

ES The centrifuge slows down until the ”open the lid” release occurs.

ER

ECR Perform an MR.

(speedometer) is 250 RPM greater than the n-max speed of the rotor.

Further cooling until NOMINAL temperature is reached.

• Insulation of speed sensor (speedometer) cable is defective.

• Loose contact on speed sensor (speedometer) cable.

• Speed sensor (speedometer) is defective.

• CC to CP is defective.

• CP or FC or SB is defective.

16/51

CP : control panel, FC : frequency converter, SB : supply board, CB : cooling board, CC : control cable, LL : lid locking, BC : braking chopper,

BR : brake resistor, MR : mains reset, EC : error cause, ES : error consequence, ER : error remedy, M : measurements, ECR : error-code reset