GEA Grasso - Start-up and Switch-off Sequences

Grasso
Refri
g
eration Division
GRASSO SYSTEM CONTROL
Chap. 2 - 4 638660E_chapter2.doc 01.2004/1
2.4 Start up sequence
2.4.1 Single stage and booster piston compressor packages
Starting conditions fulfilled
Output — compressor motor on
Feedback — compressor motor on equals 1
’Motor feedback’ timer active
Unloaded start
Release of capacity control system
Booster pressure reached
Figure 2.4, Start up sequence for single stage (A) and booster (B) piston
compressor package
A Single stage: Release of capacity control system after unloaded start.
B Booster: Release of capacity control system after that the booster pressure is reached.
•
If
(1) Starting conditions fulfilled
→
Then
(2) Set output — compressor motor on
→
Then
(4) Start ’Motor feedback’ timer
→
Then
(5) Set unloaded start
•
If
(3) Feedback — compressor motor equals 1
→
Then
(4) Stop ’Motor feedback’ timer
•
If
(5) Unloaded start ended
→
Then
(6) Release of capacity control system
or
•
If
(5) Unloaded start ended
and
(7) Booster pressure reached
→
Then
(6) Release of capacity control system