Engineering manual - UniSAB III 1.10.8
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001930 en 2021.06
Compressor control and surveillance
changes to 0. The “old” starting number is stored and reinserted if UniSAB III is configured differently
from capacity set point control.
3.1.13 Climate compensation
This function can be used for both reciprocating and screw compressors without automatic Vi regulation.
The function is included in the picture Setup/Compr.Control and is further described in chapter 6. Set-
up.
The inlet temperature set point on the water side of plants which are regulated by brine temperature or
hot water temperature can be controlled by the outside temperature. This requires a 4-20 mA tempera-
ture transducer, which is connected to the current inlet in UniSAB III as shown in the wiring diagrams in
the back of this manual.
Use a standard temperature transducer with a suitable temperature range, e.g. -30 - +25°C as shown in
Fig. 14. Note that the points of discontinuity in the diagram will be determined by the transducer measur-
ing range as seen in examples 1 and 2 below.
Fig. 14: Transducer measuring range
No further compensation will be made once the outside temperature is above the top point of discontinu-
ity and below the bottom point of discontinuity.
The factor by which the outside temperature should influence the inlet temperature positively or nega-
tively must be set in the Brine, Hot water or User regulator.
In the picture Setup/Compr. Control, select Control on = Process out (brine) or Hot water, or (with User
regulator) Ext. Cool/Ext. Heat as well as Climate compensation = “Yes” in the picture Setup/Compr.
Control.
Example 1:
On a water cooling unit, the inlet temperature is to be corrected by the outside temperature.
• If the outside temperature is +30°C or more, the inlet temperature should be +4°C.
• If the outside temperature is +0°C or less, the inlet temperature should be +12°C.
In the menu Setup/Compr. Control, set Control on to Process out and Climate compensation on Yes. Se-
lect an outside sensor with a range of 0 - +30°C.
T inlet
Sp 1 (-5°C)
Sp 2
(+25°C)
4 mA
(-30°C)
20 mA
(+25°)
T out
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