GEA Grasso - Page 37

Grasso
Refri
g
eration Division
GRASSO SYSTEM CONTROL
01.2004/1 638660E_chapter2.doc Chap. 2 - 1
2. CONTROL SEQUENCE
2.1 Overview of the operating modes
Operation modes Signal for…
Name Explanation Start/Stop Capacity +/-
0 Service Compressor motor blocked
1 Manual + Manual Manual control via OP Manual Manual
2 Manual + Auto
Manual Start/Stop via OP and full
automatic local capacity control
Manual Auto
3 Auto + Auto
Full automatic Start/Stop and local
capacity control
Auto Auto
4 Remote + HW (cont)
Start/stop and capacity demand via
digital contacts (Hardware) from a
remote Master controller. The GSC
derives from the continuous +/- signals
the pulses for controlling the compressor
capacity (indirect).
External
External
continuous
5 Remote + HW (pulse)
Start/stop and capacity demand via
digital contacts (Hardware) from a
remote Master controller.
The Master also generates the +/-
signals as pulses for controlling the
compressor capacity directly.
External External pulses
6 Remote + HW-Loc.SP
Start/stop via digital contacts
(Hardware) from a remote Master
controller. The capacity control is based
on the local set point (OP).
External Local set point
7 Remote + HW-Rem.SP
Start/stop via digital contacts
(Hardware) from a remote Master
controller. The capacity control is based
on the remote set point (analogue
input).
External
Remote set
point
8 Remote + Net (cont)
Start/stop and capacity demand via
network (MPI or Profibus-DP) from a
remote Master controller. The GSC
derives from the continuous +/- signals
the pulses for controlling the
compressor capacity (indirect).
Network
Network
continuous
9 Remote + Net (pulse)
Start/stop and capacity demand via
network (MPI or Profibus-DP) from a
remote Master controller.
The Master also generates the +/-
signals as pulses for controlling the
compressor capacity directly.
Network
Network
pulses
10 Remote + Net-Loc.SP
Start/stop via network (MPI or Profibus-
DP) from a remote Master controller.
The capacity control is based on the
local set point (OP).
Network Local set point