Johnson Controls SABROE Unisab III Control Engineering Manual page 190

Set-up
5: Common evap/cond
N/N
N/Y
Y/N
Y/Y
This point can be configured to the four values, meaning:
N/N - separate evaporator and condenser for each compressor.
N/Y - separate evaporator for each compressor, but common condenser.
Y/N - common evaporator, but separate condenser for each compressor.
Y/Y - common evaporator and condenser for each plant (i.e. compressors with same Multisab
system no.)
On plants with a common evaporator the suction pressure limiter cannot start the next com-
pressor in the sequence. This is only possible if a separate evaporator has been configured.
On plants with a common condenser the discharge limiter cannot start the next compressor in
the sequence. This is only possible on plants with separate condensers.
6: HP on two stage
No
Yes
Usually choose No. In special cases on two-stage plants Yes can be selected for HP compres-
sors. The compressors can thus be forced to start by means of the input External starting per-
mission.
Note: The compressor does not stop before the starting permission has been removed even
though there is no cooling requirement.
See detailed description in subsection 3.5.12. HP on two-stage.
7: High limit
0 to 100%
High limit is used to insert the capacity limit between 0 and 100% for the high suction pres-
sure limiter. See High suction pressure limitation in subsection 3.2.3. Special limiters.
8: Capacity output
No
Yes
Select Yes if you want to make the Unisab III capacity (Yield) signal available as an analogue
output on channel AO1. The signal will be a 4-20mA output signal corresponding to the com-
pressor capacity (Yield) signal between 0% and 100%
Select No if you are not using this function. This function cannot be used or configured if Oil
Cooling is configured to HLI 4-20mA.
9: Cap down blocked
No
Yes
Select Yes to use the Cap down blocked. See subsection 3.5.3. Capacity down blocked for
more information.
Note that the Cap down blocked function and the chiller function Flow condenser both use the
same digital input, DI11. See subsection 3.6.5. Flow condenser (ChillPAC/PAC - optional).
Always select No if you do not wish to use the Cap down blocked function.
Engineering manual - Unisab III 1.10
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