Johnson Controls SABROE Unisab III Control, Engineering Manual

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Engineering manual - UniSAB III 1.10.8
001930 en 2021.06
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Compressor control and surveillance
1) Only shown while capacity is limited.
2) If limiter is active (suction pressure > alarm limit), it will remain active until the pressure falls below the
alarm limit less 2
° C/R.
3) Limiter is not active or passive like standard limiters. It actively limits capacity so that it is less than or
equal to the selected
High limit .
3.2.5 Display indications (reciprocating compressors)
The following table shows the display texts for limiters.
Overview picture indication
Limiter
Compressor
stopped
Compressor
running
Alarm picture,
Passive
indication
Alarm picture,
Active indication
Standard Limiters:
Low suction pressure Pause Suction lim. None Suction pressure
low lim.
High discharge pressure Pause Discharge lim. None Discharge pressure
high lim.
High motor current Irrelevant Running
overload
None None
Low brine temperature Pause Suction lim. Limiting brine
temperature
Brine temperature
low lim. and limiting
brine temperature
High water temperature Pause Discharge lim. Limiting hot water Brine temperature
high lim. and
limiting hot water
High differential pressure Irrelevant Discharge lim. None High differential
pressure
Special limiters:
High suction pressure Ready Suction lim. 1) None 2) 3) Suction pressure
high lim. 3)
Suction ramp Irrelevant Suction lim. None None
High discharge
temperature Irrelevant Irrelevant None Limiting discharge
temperature
High liquid level Irrelevant Irrelevant High liquid level 4) High liquid level 4)
High suction pressure
gradient Irrelevant Irrelevant None High suction pres-
sure gradient
Table 28: Display indications - reciprocating compressors
1) Only shown while capacity is limited.
2) If limiter is active (suction pressure > alarm limit), it will remain active until the pressure falls below the
alarm limit less 2
° C/R.
3) Limiter is not active or passive like standard limiters. It actively limits capacity so that it is less than or
equal to the selected
High limit .
4) Limiter is active as long as the liquid level is high. When the liquid level gets low, limiter is passive until
the delay timer runs out.