Johnson Controls SABROE Unisab III Control, Инструкция по эксплуатации

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Engineering manual - UniSAB III 1.10.8
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001930 en 2021.06
Compressor control and surveillance
decreasing capacity slide position will be activated for maximum 300 seconds. If the capacity slide is still
higher than 10% position, a
Capacity error shutdown will be issued and the compressor will not start. If
the capacity slide is lower than 10% position the compressor is allowed to start.
Before start-up UniSAB III will also check the oil level and temperature in the oil separator. If the oil level
is too low an
oil system error alarm will be issued. No signal from the oil level switch during operation will
result in shutdown after a delay of 30 seconds.
If the oil temperature is lower than the set limits, a low oil separator temp alarm or shutdown will be is-
sued. The limits for oil separator temperature can be set in the menu Control values/Oil/Separator temp/
Limits .
If the oil level switch is active and the separator temperature is above the shutdown limit, the compressor
will start. If the differential pressure is lower than
Set point 1 , the oil pump will also start. When the com-
pressor differential pressure has been higher than Set point 2 for 60 seconds, the pump will stop.
If the differential pressure is higher than Set point 1 when the compressor is started, the oil pump will not
start.
Alarm surveillance
During start the following alarms are delayed:
Low oil pressure 45 sec.
High filter diff. pressure 300 sec.
Low superheat 300 sec.
High superheat 300 sec.
Low/high oil temperature 300 sec.
The delayed alarms are described in section 6.5 Timers .
Stopping sequence
When SAB 120 and 151 compressor stops, UniSAB III will attempt to move the capacity slide below
10% position. The solenoid valve for decreasing capacity slide position is activated for maximum 300
seconds. If the capacity slide is not below 10% within the 300 seconds a
Capacity error shutdown will be
issued.
Vi ratio regulation
UniSAB III regulates the Vi ratio in three steps according to the actual pressure ratio. Before switching
from one Vi-step to another, the actual Vi ratio for the compressor must have been present for at least
the time indicated in timer 34
Vi-pause (60 seconds). Otherwise the change of the Vi step will be can-
celled. The Vi-step stays in volume ratio 2.2 (0.0%) until the compressor capacity is higher than 40%.
Vi slide position
../Capacity/Vi slide
pos.
Dig. output 11 (V1) Dig. output 12 (V2)
Volume ratio 2.2 0.0 % On On
Volume ratio 3.5 65.3 % Off On
Volume ratio 5.0 100.0 % Off Off