Sab 283 Mk 1, Sab 330 And Sab 355 Mk 1 With Oil Pump - Johnson Controls SABROE UniSAB III Engineering Manual

Alarm surveillance
During start the following alarms are delayed:
Low oil pressure
High filter diff. pressure
Low superheat
High superheat
Low/high oil temperature
The delayed alarms are described in section 6.5 Timers.
Stopping sequence
When GST compressor stops, UniSAB III will attempt to move the capacity slide below 5% position. The
solenoid valve for decreasing capacity slide position is activated for maximum 300 seconds. If the ca-
pacity slide is not below 5% within the 300 seconds a Capacity error shutdown will be issued.
Vi ratio regulation
UniSAB III regulates the Vi ratio in three steps according to the actual pressure ratio. Before switching
from one Vi-step to another, the actual Vi ratio for the compressor must have been present for at least
the time indicated in timer 34 Vi-pause (60 seconds). Otherwise the change of the Vi step will be
cancelled.
Volume ratio 2.2
Volume ratio 3.5
Volume ratio 5.0
3.3.15

SAB 283 Mk 1, SAB 330 and SAB 355 Mk 1 with oil pump

The pump is used for prelubrication and to maintain a minimum oil pressure level during operation. The
pump is started and stopped in accordance with the compressor differential pressure (discharge pres-
sure - suction pressure) during operation.
The difference is set in the picture Oil/Pressure/Control whereupon Set point 1 and Set point 2 will
appear.
Set point 1 is the pump start pressure and Set point 2 is the pump stop pressure. Therefore, Set point 1
must be set to the lowest pressure level.
Normal setting for SAB 283 Mk 1/330/355 Mk 1:
Set point 1 = 2.5 bar
Set point 2 = 4.0 bar
Move the cursor to Set point 1, press
value and then press
Adjust Set point 2 the same way.
If the compressor differential pressure is below Set point 1 during operation, the pump will start
immediately.
When the compressor differential pressure has been higher than Set point 2 for 60 sec, the pump will
stop.
45 sec.
300 sec.
300 sec.
300 sec.
300 sec.
Vi slide position
../Capacity/Vi slide
pos.
0.0 %
65.3 %
100.0 %
to enter the parameter change field, use
to store the value.
Dig. output 11 (V1)
On
Off
Off
Engineering manual - UniSAB III 1.10.8
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Compressor control and surveillance
Dig. output 12 (V2)
On
On
Off
and to adjust the
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