Johnson Controls SABROE UniSAB III Engineering Manual page 217

Set-up
point for this value is entered in Control values/Discharge/Temperature/Control, Set point 2. The set
point has a fixed hysteresis of 5°K.
Example:
Sp2 = 90°C. Cooling starts at 90°C and stops at (90-5) = 85°C.
Adjusting range: -20°C-+150°C.
Factory value: 100°C.
The regulator controls the solenoid valve through the liquid injection digital output.
6: Oil rectifier
No
Yes
The oil rectifying function is used on brine plants in marine execution. If selecting this function also check
the timers Oil Rectifying Start, Oil Rectifying Delay and Oil Rectifying Blocked.
7: Oil flow control
No
Yes
Select Yes for compressor types SAB 193 H–355 H and SAB 273 S to enable oil flow control and dis-
charge temperature difference supervision.
The oil flow control PID regulator controls a motor valve on AO1 with the motor speed ratio as input sig-
nal. At raising RPM ratio, the regulator must open the motor valve.
When the compressor is stopped (motor feedback is OFF), the motor valve must not be closed, but the
regulator must continue in operation.
When oil flow control is enabled, the two parameters oil flow open max (valve opening degree at max.
speed) and oil flow open min (valve opening degree at min. speed) can be set:
The motor valve opening degree is given as: AO1 [%] = K
Where:
motor speed ratio = actual motor rpm / motor rpm max
K = oil flow open max – K
0
K = (oil flow open max – oil flow open min) / (1 – motor rpm min / motor rpm max)
1
The supervision of low discharge temperature difference is active when the compressor is running at
"Full capacity".
The alarm low discharge temperature difference is released if the discharge temperature difference is
below low alarm limit.
See detailed description in subsection 2.2.44 Low discharge temperature difference alarm.
Note: When the oil flow control parameter is enabled, the oil cooling parameter HLI 4-20mA cannot be
set.
8: Oil flow open max
5 to 100% [70%]
This parameter is used when the oil flow control function is enabled. It defines the valve opening degree
at maximum speed.
The oil flow open max parameter is used for the oil flow control function, see detailed description under
7: Oil flow control above.
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+ K x motor speed ratio
0 1