Wrong Starting Number In Sequence; Limiting Suction Pressure; Limiting Discharge Pressure; Limiting Process Out Temperature - Johnson Controls SABROE UniSAB III Engineering Manual

Alarms and shutdowns
2.2.15

Wrong starting number in sequence

The reason for the alarm is that two or more compressors have the same starting number and the same
system number.
2.2.16

Limiting suction pressure

The alarm indicates that the suction pressure limiter is active, i.e. the suction pressure is within the limit-
er neutral zone or below the alarm limit.
2.2.17

Limiting discharge pressure

The alarm indicates that the discharge pressure limiter is active, i.e. the discharge pressure is within the
limiter neutral zone or above the alarm limit.
2.2.18

Limiting process out temperature

The alarm indicates that the process out temperature limiter is active, i.e. the process out temperature is
within the limiter neutral zone or below the alarm limit.
2.2.19

Limiting hot water

The alarm indicates that the hot water temperature limiter is active, i.e. the hot water temperature is with-
in the limiter neutral zone or above the alarm limit.
2.2.20

Limiting discharge temperature

The alarm indicates that the discharge pipe temperature limiter is active. See section 3.2 Limiting func-
tions, High discharge pipe temperature.
2.2.21

Start-up limiter

SABflex and SABCube compressors (SAB 109→ → 159)
The alarm indicates that the SSSTV valve is closed and that the speed might be limited to 1.000 [rpm]
during start-up. This will be caused by too high external (or internal) suction pressure or too low oil pres-
sure. The start-up limiter can maximum be active for the time set in timer Max. start-up time, which de-
fault is set to 600 sec.
When the Max. start-up time timer is running the Start-up limiter is an alarm. When the Max. start-up
time timer runs out the Start-up limiter alarm is converted into a shutdown and the compressor is
stopped.
2.2.22

Start up RPM limiter

High-pressure compressors (SAB 157 HR)
The alarm indicates that the speed is limited to minimum speed, default 1,000 [rpm] during start-up be-
cause of too high suction pressure.
The start-up limiter can maximum be active for the time set in timer Start RPM limiter (default 300 sec-
onds). When the limiter is active the Start RPM limiter timer is running and a Start-up RPM limiter alarm
is shown. If the Start RPM limiter timer runs out while the limiter is still active, the compressor is stopped
by a shutdown Start RPM limiter error.
2.2.23

Lube pressure unload alarm

High-pressure compressors (SAB 157 HR)
This alarm indicates that the oil lubricating pressure is low and that the plug valve therefore has been un-
loaded. See Fig. 7.
Engineering manual - UniSAB III 1.10.8
001930 en 2021.06 55/346