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0171-761-EN
Appendix
Setting of pressure and temperature warning limits for screw compressors
Suction pressure:
Set low alarm to stop the compressor 8K
lower than the evaporating temperature. Set
low warning 3 K lower than the evaporating
temperature.
Discharge pressure:
Set high alarm to stop the compressor 2 bar
higher than the condensing pressure, how-
ever max. acc. to the values stated in the fol-
lowing table:
Booster operation
SAB 110/128/163
female drive
VMY Mk 2/2.5/3
SAB 110/128/163
male drive
8 bar
18 bar
23 bar
23 bar
High warning always 1 bar lower than the
alarm.
Differential pressure, lubricating oil:
- SAB 128 Mk1 and 163 Mk1:
Set low alarm to stop the compressor at a
differential pressure of 2.5 bar. 1.0 bar,
however, for SAB 128/163 in booster
operation.
- SAB 110, SAB 128 Mk2
and SAB 163 Mk2:
Set low alarm to stop the compressor at a
differential pressure of 0 bar.
Always set low warning 0.5 bar higher
than the alarm.
Diff. pressure, oil system:
- SAB 110/128/163 and VMY Mk 3 with-
out full-flow pump:
Set high alarm to stop the compressor at
a diff. pressure of 4 bar on units with oil
cooler and 1.5 bar on units with HLI/BLI
oil cooling.
High warning always 0.5 bar lower than
alarm.
- VMY Mk 2.5 and VMY Mk 3 with full-
flow pump:
Set high alarm at 1 bar.
High warning always 0,5 bar lower than
alarm.
- On VMY Mk 2/2.5 and VMY Mk 3 with
full-flow pump, pressostat RT260A for
oil diff. pressure must be set at 1 bar.
Superheat:
Set low alarm at 0 K in connection with
flooded evaporator and 2 K in connection
with expansion valve systems.
Low warning always 1 K higher.
Summary of Contents for UNISAB S-Control
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