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Engineering manual - UniSAB III 1.10.8
001930 en 2021.06

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Alarms and shutdowns

Note 10

A 0.0 setting disables alarm/shutdown monitoring.

Note 11a

300 sec. delay, regardless of when limits are exceeded.

Note 11b

600 sec. delay, regardless of when limits are exceeded.

Note 12

The compressor must have been above 5% capacity.
When below 5% capacity alarm/shutdown monitoring is disabled.

Note 13

Shutdown monitoring delayed 15 sec. after compressor start.

Note 14

60 sec. delay, regardless of when limits are exceeded.

Note 15

HPC, HPO and HPX compressors only.

Note 16

Shutdown monitoring delayed 20 sec. after compressor start.

Note 17

For VMY Mk 2-2.5, calculate the following: (see Fig. 6) Oil pressure = Oil pressure
3 (after oil filter) - Discharge pressure 2. For all other compressor types (except
SAB 80, see Note 20), calculate the following: Oil pressure = Oil pressure 3 (after
oil filter) - Suction pressure 1.

Note 18

The limits are not active until

Ext. inp. s.

has been selected in the menu

Setup

Configuration/External input

Note 19

For SAB 80 the differential pressure across the oil filter is calculated as follows:
(see Fig. 6) Oil filter diff. pressure = Discharge pressure 2 - Oil pressure 4 (after oil
filter).
The stated oil filter pressure will thus be 0.1 to 0.7 bar higher than the actual pres-
sure loss across the filter due to the pressure loss across the oil separator and the
oil cooler.
The maximum allowed pressure drop across the oil filter is 1.2 bar. Consequently,
the alarm limit should be set between 0.8 and 1.4 bar or lower. The shutdown limit
should be set between 1.1 and 1.7 bar or lower.

Note 20

Set points 1 and 2 are used for shutdown monitoring of the mechanical oil pump,
see Engineering manual. For SAB 80, S50, S70 and S93 the oil pressure is calcu-
lated as follows: (see Fig. 6) Oil pressure = Oil pressure 3 (after pump) - Suction
pressure 1.
For SAB 80, S50, S70 and S93 the differential pressure across the oil pump is cal-
culated as follows: (see Fig. 6) Oil pump pressure = Oil pressure 3 (after pump) –
Oil pressure 4 (before pump).

Note 21

The set points are only used if the compressor is equipped with an electrical oil
pump. The set points are used to control the oil pump. When the differential pres-
sure (discharge pressure - suction pressure) falls below set point 1, the oil pump
will start. When the differential pressure exceeds set point 2 for 60 seconds, the oil
pump will stop.

Note 22

The set points are used to control the full flow pump. When the pressure falls be-
low set point 1, the full flow pump will start. When the pressure exceeds set point 2
for 60 seconds, the full flow pump will stop.

Note 23

The set points are used for liquid slugging, alarm and shutdown. This alarm/shut-
down is released by a sudden decrease in discharge temperature which is greater