Johnson Controls SABROE UniSAB III User Manual

Engineering manual - UniSAB III 1.10.8
001930 en 2021.06
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Set-up
6.3 Multisab
6.3.1 Multisab
The Multisab sequencing status for this compressor is found in menu Setup/Multisab. The look of this
picture depends on whether the configuration point Rotatune is set to Yes or No.
If Rotatune is set to No the picture will appear like this:
Multisab status
Multisab status can be one of the following:
State
Explanation
0 Blocked
The compressor cannot (and is not going to) start Multisab now.
1
Not my turn
Another compressor must start before this one/there is no cooling
requirement.
2
May start
Starts when Start delay expires as there is now a cooling
requirement.
3
Runs at max. cap.
Must run at 100% capacity.
4
Lead compr. Runs in parallel operation as master.
5
Lag compr. Runs in parallel operation as slave.
6
May stop
Is below 5% capacity, stops when Stop delay expires.
7
Runs by itself
Is the only compressor in operation in the system.
8
Stop ramp up Stops parallel operation, as master - screw compressors only
9
Stop ramp down Stops parallel operation, as slave - screw compressors only
10
Rotatune master Runs in parallel operation as rotatune master
11
Rotatune slave Runs in parallel operation as rotatune slave
Table 42: Multisab states of UniSAB
Parallel offset
Parallel offset can be set between +10.0% and -20.0%. The offset value is added to the calculation of
Screw parallel cap. [%]. After entering an offset value (not 0) the Screw parallel cap. value will be re-
duced accordingly. Note that the offset value is not changed by a Factory reset.
If the offset is negative, it means that the point at which the lag (screw) compressor is stopped is re-
duced by the offset value. This may be useful when water chillers are running in parallel as these units
may have a relatively better COP at part load (heat transfer being better at part load).
If the offset is positive, it means that the point at which the lag (screw) compressor is stopped is height-
ened by the offset value. This may be useful when the system consists of small Rotatune reciprocating
compressors with only one capacity step. These compressors may not be able to run at capacities much
below 50%.
For example, if you have a system with two SMC 104 Rota compressors set to min. speed 700 rpm and
max. speed 1500 rpm, the minimum capacity for these compressors is 46.6%.

Johnson Controls SABROE UniSAB III Specifications

General

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