25. Oil rectifier start
Whenever the compressor starts, this timer will be activated and start counting down. When 0
has been reached, the solenoid valve to the oil rectifier will be activated.
26. Oil rectifier delay
If suction gas superheating drops below set point 1 for superheating, the solenoid valve will
close. Once the superheating rises above this limit again, the timer must expire before the
solenoid valve opens.
27. Oil rectifier disable
If suction gas superheating drops below set point 1 for superheating, the timer will start
counting down. Provided the superheating still remains below the limit once the timer has
reached 0, an alarm will be issued.
28. Start high pressure
On two-stage plants the HP compressors can be started by force by activating the input Exter-
nal starting permission, normal stop. The start will be delayed for the set number of seconds.
With the compressors in sequence, number 1 in the sequence will start and the system will
now operate normally.
29. No Chiller
When Unisab III is configured as part of a Chiller control, the timer will ensure that communi-
cation between Unisab III and the connected chiller does not disappear for a period longer
than the set time. If this happens, both Unisab III and Unisab III-Chiller will be stopped by
the shutdown.
30. Cap. negative
When the compressor is started, the slide must move to the position corresponding to the set
zero point (i.e. positive read capacity) as quickly as possible before the expiry of the cap.
negative timer. Otherwise an error message will be issued. The cap. negative timer counts
down each second by the value:
10
(Corrected capacity)2
Corrected capacity is shown in the display when the compressor is started. It may be a nega-
tive value between 0 and -30%, i.e. the timer will count down each second by a factor be-
tween 1 and 90. Each time the slide moves above 0% capacity, the timer will stop. The timer
is reset and restarted as soon as the slide moves below -2% corrected capacity.
31. Unloaded start
The timer is used in connection with the compressors FV 17/19. When the compressor motor
is started, a by-pass solenoid valve for oil discharge will open for the time set.
The timer is used in connection with the compressors FV 24/26. When the compressor motor
is started and stopped, the slide capacity down solenoid valve will open for the time set.
1. For FV17/19 and FV25/26
2. For SAB xxx HR
3. SABflex and SABCube
Set-up
Engineering manual - Unisab III 1.10
001930 en 2014.09
219/319
To Next Page
Loading...
Need help?
General
