Compressor Control - Chiller Functions; Process Out Temp; Process In Temp - Johnson Controls SABROE UniSAB III Engineering Manual

Compressor control and surveillance
3.6

Compressor control - chiller functions

Please note that when using the chiller functions described in this section there are certain limitations in
the use of some of the other UniSAB III functions, e.g. oil cooling functions.
• When the chiller function Level control LP/HP or Expansion control DX is used it is not possible
to use the By-pass function - and vice versa.
• When the chiller function Level control LP/HP or Expansion control DX or the By-pass function
is used it is only possible to use the following two oil cooling functions:
– Water cooling for reciprocating compressors
– Intermediate liquid injection for two step reciprocating compressors
All other Oil cooling functions are blocked and cannot be used.
• When the chiller function Flow condenser is used it is not possible to use the Cap down blocked
function - and vice versa.
• When the new Thermo pump - internal function is used it is only possible to use the chiller func-
tions Oil return from oil separator and Flow condenser.
Chiller function
configured

Process out temp.

Process in temp.

Oil return from oil separator
Oil return from evaporator
By-pass function
(or level control LP/HP)
(or expansion control DX)
Flow evaporator
Flow condenser
Liquid level limiter
Level control LP/HP
Expansion control DX
Table 32
3.6.1 Process out temp.
Display and monitor the analogue input Process out temperature in the picture Control values/Process
temp/Process out temp/Values.
Alarm and shutdown supervision settings are made in the picture Control values/Process temp/Process
out temp/Limits.
The PID regulator settings for compressor capacity regulation are made in the picture Control values/
Process temp/Process out temp/Control. This function is enabled in Set-up/Configuration/Plant/Proces
out temp. Monitoring is always active and the PID regulator is active when the compressor is running.
3.6.2 Process in temp.
Display and monitor the analogue input Process in temperature in the picture Control values/Process
temp/Process in temp/Values.
Engineering manual - UniSAB III 1.10.8
001930 en 2021.06
Other functions using these I/O
Used I/O
AI6
AI5
DO19
Thermo pump - internal (recip.)
DI13
Oil return (recip.)
DO18
Oil rectifier (screw)
Oil cooling - normal (screw/recip.)
Thermo pump - external (recip.)
Thermo pump - internal (recip.)
DO16
Dual 4-20 mA HLI valve (screw)
HLI - AKV stop valve (screw)
Motor valve (screw)
Thermo pump - internal (recip.)
DI12
Cap down blocked
DI11
Filter diff. pressure
DI5
DO016 See By-pass function
AI3
AO2
145/346