GEA Grasso - Page 20

Grasso
Refri
g
eration Division
GRASSO SYSTEM CONTROL
Chap. 1 - 8 638660E_chapter1.doc 01.2004/1
Unloaded start 
Motor feedback 
Auto start dly 
Unloaded start: Remaining time for unloaded start in secs
Motor feedback: Remaining time for motor running feedback signal from
compressor drive motor starter
<< Actual values 01 >> Auto start dly: Remaining time for automatic start delay in secs
Step time 
Limit time 
Run hours 
Step time: Remaining time for next capacity step in secs
Limit time: Remaining time for the capacity limitation in secs
Run hours: Number of operating hours
<< Actual values 01
1.2.3.2 Control settings menu
10 Control settings
Set Point 1 
Set Point 2 
Active SP 
Set Point 1: First Set Point for the controlled parameter °C
Set Point 2: Second Set Point for the controlled parameter °C
Active SP: Active Set Point in °C
<< Control 01 >> The active set point value is displayed. 2 different set point values can be
entered via the display. The switchover takes place due to a potential free
contact or due to MPI/Profibus-DP communication.
Furthermore, an external set point (analogue input or MPI/Profibus-DP
signal) can be activated. This switchover takes place due to the selected
operation mode in the menu “Operating mode”
.
Active SP 
Neutral zone 
Prop zone 
Active SP: Active set point in °C
Neutral zone: Neutral zone of the automatic capacity regulation in K
Prop zone: Proportional zone of the automatic capacity regulation in
<< Control 01 >> K
Step times min | max
Cap inc | 
Cap dec | 
Cap inc min: Minimal step time for increasing the capacity in secs
Cap inc max: Maximal step time for increasing the capacity in secs
Cap dec min: Minimal step time for decreasing the capacity in secs
<< Control 01 >> Cap dec max: Maximal step time for decreasing the capacity in secs
Auto start dly 
Pump down 
Stop pressure 
Auto start dly: Time for automatic start delay in secs
Pump down: Selection between “with” or “without” pump down
Stop pressure: If pump down is activated, the compressor does not stop
<< Control 01 >> before the suction pressure reaches this value in bar (a)
Boost press 
Cor P-zone 
Derative fact 
Boost press: Booster pressure in bar (a) .
Cor P-zone: Correction value of the proportional zone in K for
decreasing the capacity (+ towards the set point / - away
<< Control 01 from set point)
Derative fact: Maximum temperature difference in K allowed within 5
seconds otherwise the capacity will be changed
immediately (0 = derative function deactivated)