Johnson Controls SABROE UniSAB III User Manual

Engineering manual - UniSAB III 1.10.8
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001930 en 2021.06
Set-up
Select VSD Total for SMC compressors mounted with frequency drive (VSD) and Centa soft coupling.
This choice is made if the compressor should be able to run totally unloaded, i.e. be able to run down to
0% capacity. Never select VSD Total for compressors mounted with Rexnord coupling.
If Normal, Total or Additional steps is chosen for cylinder unloading, Speed is only available with
Supervisor password.
If VSD Normal or VSD Total has been chosen for cylinder unloading, Step and Speed are both available
with Superuser password.
The VSD cylinder unloading VSD Total also features the ability to run totally unloaded. It works the
same way as with total unloading at fixed speed, i.e. running Total.
Cylinder unloading
Normal Total
Additional
steps
VSD
Normal
VSD
Total
None
VSD algorithm Standard
A203 Extended
(A210)
A201
Step
(COP optimised)
Rexnord Rexnord Rexnord Centa Centa Rexnord
Speed
(Regulating
optimised)
(Rexnord) (Rexnord) (Rexnord)
Centa Centa
(Rexnord)
Table 45: Cylinder unloading
18: Unload assist
Yes
No
Select Yes for compressor types SAB 120-151, SAB 193-355, SAB 193 H-355 H and SAB 273 S if it is
difficult to unload the compressor from 100% (takes too much time). The function helps separating the
capacity slide and the Vi slide without too much delay.
19: Cap.dec.assist rate
(Capacity decrease assist rate)
1% to 5% (default 5%)
The unload assist will try to reduce the capacity position with the specified % or until capacity has been
reduced to 99%.
For SAB 120-151 the max. limit is 15%.
20: Volume dead band
3%-70% (default 3%)
This setting defines if the volume slide should be decreased or increased when the unload assist is ac-
tive.
Example: If the setting is 10% and the volume slide position is above 90% the volume slide will be de-
creased. If the volume slide position is below 90% the volume slide will be increased.
21: Oil filter diff.
Yes
No
Select No if the compressor is a reciprocating compressor type SMC/TSMC/HPC with a differential
pressostat. With this function set to no, the oil filter differential pressure is supervised with a differential
pressostat connected to the digital input DI5.

Johnson Controls SABROE UniSAB III Specifications

General

Brand	Johnson Controls
Model	SABROE UniSAB III
Category	Control Systems
Language	English