Johnson Controls SABROE Unisab III Control Engineering Manual page 127

Compressor control and surveillance
• Ready ext.
• Ready/me only
• Running at max. cap.
This function is connected to a digital output. See wiring diagrams.
Explanation
• Ready
If selecting this function, the output will be activated when the compressor is ready
for operation in Remote/Auto. This means that Auto start has been configured (and
Auto stop), external starting permission - normal stop has been set. There are no
alarms and the compressor can start.
• At min. cap.
If selecting this function, the output will be activated when the compressor is below
Signal low which is set in the same menu Configuration/Aux Output. The hysteresis is
1%.
• At max. cap. Select this function and the output is activated when the compressor is
above Signal high which is set in the same menu Configuration/Aux Output. The hys-
teresis is 1%.
Please note that the line Signal low or Signal high is not included in the menu until the
auxiliary output has been selected as either At min. cap. or as At max. cap.
• Running
If selecting this function, the output will be activated whenever the compressor is op-
erating, i.e. when the start signal to the compressor has been set.
• Ready ext.
This function corresponds to the Ready function, but here it is not required that exter-
nal starting permission - normal stop is set for the output to be activated. The func-
tion works both in Remote and Auto.
• Ready/me only
This function means that the compressor is ready, that it has the lowest start number
and that it is the only compressor in operation on this system. The output can be used
to ensure constant water circulation by the PT 100 sensor whenever a compressor is
ready to start.
• Running at max. cap.
Select this function to activate the output when the compressor is running at the
maximum possible capacity, i.e. on one of the following conditions:
• The compressor is running at max. capacity i.e. above Signal high = 100%,
where signal high is set in the same menu Configuration/Aux Output. The hys-
teresis is 1%.
• A capacity limiter is active, i.e. the compressor is running in one of the follow-
ing three limiting status:
-
-
-
When a capacity limiter is active it will prevent the compressor from reaching
100%.
Engineering manual - Unisab III 1.10
001930 en 2014.09
Overload (current)
Discharge (overload)
Suction (overload)
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