![Hettich ROTINA 420 Repair Instructions Download Page 8](http://html1.mh-extra.com/html/hettich/rotina-420/rotina-420_repair-instructions_2127804008.webp)
8/97
These microprocessor controlled centrifuges mainly consist of the following electrical
components:
•
Operating panel (A2)
•
Electronics ROTINA 420 (A1) resp. Electronics ROTINA 420R (A1)
•
Motor (M1) with 2 speed sensors (B2.1, B4) and an imbalance sensor (B2.2)
•
Brake resistor (R1)
•
Motor-driven lid lock (A3)
•
Cooling system
3.2 Operating
panel
(A2)
The buttons, the LCD display, the status LEDs and the acoustic beeper are located on
the operating panel.
The operating panel is connected with the Electronics (A1) via a 20-pole flat ribbon
cable.
3.3
Electronics ROTINA 420 (A1) resp. ROTINA 420R (A1)
There are 2 microprocessors on the Electronics. Both processors (control- and drive-
processor) are communicating internal via a serial interface.
The control-processor carries out the following tasks:
•
Reading in the buttons and controlling the LCD display and the LEDs.
•
Saving of 99 run programs.
•
Evaluating the errors recognized by the frequency converter.
•
Voltage supply and evaluation of both speed sensors (B2.1, B4, speedometer).
•
Voltage supply and evaluation of the imbalance sensor (B2.2).
•
Controlling the motor-driven lid lock.
•
Voltage supply 15 V DC and 5 V DC for the operating panel.
•
Evaluating the temperature sensors T1, T2 (B1, B3) and controlling the cooling.
•
Evaluating the overtemperature switch in the centrifuge chamber.
•
Status indication with a yellow LED:
All functions are all right:
the yellow LED lights up
The frequency converter carries out the following tasks:
•
Generating the motor current supply
(three-phase current with variable frequency and voltage)
Functional description: The supply voltage is rectified, smoothened and
chopped into a pulse width pattern in three bridge
elements with a microprocessor.
•
Monitoring the motor current.
•
Evaluating the overtemperature switch in the motor (M1).
•
The braking chopper transfers the electrical energy produced during braking, from a
voltage of approx. 400 Volt, to the brake resistor in a controlled manner.
Summary of Contents for ROTINA 420
Page 1: ...06 08 Andreas Hettich GmbH Co KG AR4701EN ROTINA 420 ROTINA 420 R Repair instructions ...
Page 78: ...77 97 Fig 2 Fig 3 3 1 5 4 6 7 a b d 13 16 18 17 19 21 22 30 25 23 38 21 20 b a c d ...
Page 80: ...79 97 Fig 6 Fig 7 Fig 8 9 10 12 11 7 8 a b 29 28 27 26 41 43 44 41 39 42 40 42 45 a c b d d ...
Page 95: ...94 97 11 3 2 Connecting diagram ROTINA 420 420 R ...
Page 96: ...95 97 ...
Page 97: ...96 97 ...