Johnson Controls SABROE UniSAB III Engineering Manual page 81

Compressor control and surveillance
All regulators for capacity regulation (suction pressure, process temperature etc) can have two set
points which are selected by opening/closing a digital input named Regulator Sp1/Sp2 (see wiring dia-
grams). Note that also the Motor Current Limiter has two set points, which are selected with another dig-
ital input named Motor Sp1/Sp2.
Control on = Suction pressure
The pressure is measured by the built-in pressure transducer on the compressor suction side. The regu-
lator is set by selecting Control values/Suction/Pressure Bar/Control or Control values/Suction/Pressure
Deg./Control followed by repeated pressures on until reaching the bottom of the picture. Note that the
Neutral zone and the P band can only be selected when the pressure is shown in °C/R (Deg.).
Control on = Process out (Brine)
The process out (brine) temperature is measured by a Pt 100 sensor connected to the process out tem-
perature input (see wiring diagrams). Position the sensor on the spot where the temperature should be
regulated. The sensor is not built into the compressor. The regulator is set by selecting Control values/
Process temp/Process out temp./Control followed by repeated pressures on until reaching the bottom
of the picture.
Control on = discharge pressure
The pressure is measured by the built-in pressure transducer on the compressor discharge side. The
regulator is set by selecting Control values/Discharge/Pressure Bar/Control or Control values/Dis-
charge/Pressure Deg./Control followed by repeated pressures on until reaching the bottom of the pic-
ture. Note that the Neutral zone and the P band can only be selected when the pressure is shown in °C/
R (Deg.).
Control on = Process out (hot water)
The process out (hot water) temperature is measured by a Pt 100 sensor connected to the process out
temperature input (see wiring diagrams). Position the sensor on the spot where the temperature should
be regulated. The sensor is not built into the compressor.
The regulator is set by selecting Control values/Process temp/Process out temp./Control followed by re-
peated pressures on until reaching the bottom of the picture. Note that the Process out temperature
regulator at this stage functions as a hot water regulator. The difference is that the compressor will load
capacity at decreasing temperature.
Engineering manual - UniSAB III 1.10.8
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