Compressor Control - Screw Compressors; Start Sequence; Sab 163 Mk 1 With Oil Pump; Sab 110/128/163 Mk 2 Without Oil Pump - Johnson Controls SABROE UniSAB III Engineering Manual

3.3

Compressor control - screw compressors

3.3.1

Start sequence

The various types of reciprocating and screw compressors start up in different ways. Some types have
prelubrication and others start up directly. They all have certain alarms which are suppressed at this
stage as described in chapter 2. Alarms and shutdowns and section 6.5 Timers.
The starting sequence and alarm surveillance are described for a number of different screw compressor
types in subsections 3.3.2 to 3.3.20
3.3.2

SAB 163 Mk 1 with oil pump

Once the compressor has received starting permission, the pump will start. The built-in spring ensures
that the capacity slide is in minimum position.
The oil is pumped into the compressor lubrication system and when the oil flow switch is activated, the
prelubrication period will begin. When this period has expired, the compressor will start and the pump
will work for 300 seconds and then stop.
On booster compressors the pump will run continually during operation to ensure sufficient pressure to
move the capacity slide. See also section 6.5 Timers.
Alarm surveillance
During start the following alarms are delayed:
Low oil pressure
High filter diff. pressure
Low superheat
High superheat
Low/high oil temperature
See also section 6.5 Timers.
3.3.3

SAB 110/128/163 Mk 2 without oil pump

Once the compressor has received starting permission, the built-in spring ensures that the capacity slide
is in minimum position. Start the compressor and wait for a signal from the oil flow switch for max. 50+10
seconds. If there is no signal from the oil flow switch for 10 seconds during operation, the compressor
will stop.
Alarm surveillance
During start the following alarms are delayed:
Low oil pressure
High filter diff. pressure
Low superheat
High superheat
Low/high oil temperature
See also section 6.5 Timers.
300 sec.
300 sec.
300 sec.
300 sec.
300 sec.
45 sec.
300 sec.
300 sec.
300 sec.
300 sec.
102/346
Compressor control and surveillance
Engineering manual - UniSAB III 1.10.8
001930 en 2021.06