Description Of The Grasso System Control - GEA Grasso Manual

Grasso
Refrigeration Division
1

DESCRIPTION OF THE GRASSO SYSTEM CONTROL

1.1 Grasso System Control - General
The GSC consists of the control unit with operator keypad and display unit, indicator lights for "Running",
"Warning" and "Alarm", emergency stop button, output relays etc.
The standard GSC is directly mounted on the compressor package unit. However, the GSC can also be located in
a control centre.
The GSC performs the following functions:
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Display of all physical and technical parameters - e.g. pressure, temperature, motor current, capacity, number
of hours run, operating mode and status signals.
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Automatic start up and shut down of the compressor unit and capacity regulation dependent on the
following parameters:
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Monitoring of all operating parameters.
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Compressor capacity limitation, in case the discharge pressure, discharge temperature, suction pressure,
secondary refrigerant temperature or motor current limits are approached.
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Alarm memory with date and time.
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Wire failure detection of analogue input signals.
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Password protection for preventing unauthorised access to parameters.
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Program memory on EPROM.
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Control of the compressor unit by a master controller via potential free contacts.
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MPI or Profibus-DP communication with a master controller.
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Freeze display with all operating parameters just before appearance of the last alarm that results in the unit
to shutdown.
1.1.1 View
Figure 1.1: View of outside of switchgear cabinet
01.2004/1
- suction pressure
- external temperature (analogue or network input)
- inlet temperature (Chiller only)
- outlet temperature (Chiller only).
638660E_chapter1.doc
GRASSO SYSTEM CONTROL
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6
1 Power supply
2 Profibus DP/DP-coppler
3 Socket-outlet for service
Figure 1.2: View of inside of switchgear cabinet
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2
4 Emergency stop relay
5 Motor start relay
6 Bus Terminal
Chap. 1 - 1