Low Suction Pressure; Lubricating Pressure; Vi-Pause; Low Oil Flow - Johnson Controls SABROE UniSAB III Engineering Manual

Set-up
The timer is used in connection with the compressors FV 24/26. When the compressor motor is started
and stopped, the slide capacity down solenoid valve will open for the time set.
1. For FV17/19 and FV25/26
2. For SAB HR
3. SABflex and SABCube

32. Low suction pressure

During start-up and operation the shutdown for low suction pressure is delayed for the indicated period
of time.

33. Lubricating pressure

During start-up and operation the shutdown for lubricating pressure is delayed for the indicated period of
time. An alarm is issued after 25 seconds.
1. For screw compressors
2. For SAB 157 HR

34. Vi-pause

The timer is used in connection with Gram GST, SAB 120→SAB 151 and SABCube compressors, which
have automatic step regulation of the volume ratio. Gram GST and SAB 120→151 have three steps and
SABCube has two. Before switching from one Vi step to another, the actual Vi ratio for the compressor
must have been present for at least the indicated time. If not, the change of the Vi step will be cancelled.
1. For Gram GST and SAB 120→151
2. For SABflex and SABCube
35. Oil log alm (oil log shutdown)
For GSV/RWF/SAB 193→ 355 compressors with oil pump (does not apply to SAB 120 → 151).
This timer starts the oil pump before start-up and when the compressor stops if the capacity slide is
above 5%. If capacity is not below 5% before the timer runs out, a shutdown is issued for the oil log shut-
down. Note that there is a risk of overfilling the compressor with oil which may damage it at next start-up
if this timer is set too high.
If the Oil log alarm have been activated, and the oil pump now have been running for 2 times 30 sec-
onds, the compressor must rest for 15 minutes before restart, or the compressor shaft must be turned
10 times in the normal rotation direction.

36. Low oil flow

This timer is activated if the alarm Insufficient oil main pressure is activated and the capacity slide is
above 50%. If the timer runs out before capacity gets below 50%, a shutdown for insufficient oil main
pressure is issued. See section 2.2 Other alarms and shutdowns for more details about this shutdown.
1. For SAB 120→355
2. For SAB 157 HR
37. Oil cir.alarm (Low oil circuit pressure alarm)
For SGC compressors (SAB 120→151, SAB 193→355, SAB 193 H→355 H, SAB 157 HR and SAB 273
S)
This timer starts if the difference in pressure between oil pressure and discharge pressure exceeds 1.7
bar.
During start-up and operation, the alarm Low oil circuit pressure alarm is delayed for the stated period of
time.
Engineering manual - UniSAB III 1.10.8
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