Parallel Compression Control; One Modulating Compressor Only; Two Or More Compressors - Carel pR300T Mode D'emploi

5.
If parallel compression is managed by an external board, this must be confi gured using the Wizard,
considering that the system manages suction only
and that the control set point is the pressure required in the CO
The following confi gurations are recommended for controlling the compressor or compressors used for
parallel compression.

One modulating compressor only

If there is only one modulating compressor, proportional plus integral control (P+I) is recommended. The set
point can be the same used for receiver pressure control using the fl ash valve. One possible confi guration
is shown below:
•
PROP.+INT. control
•
set point 35 barg
•
diff erential 2 barg
•
integral time 120 seconds

Two or more compressors

If the parallel compression is managed using more than one compressor, the recommended control strategy
is dead zone.
In this case, the control set point should be set slightly lower (e.g. 1 barg) than the fl ash valve set point; this
ensures prompt activation of parallel compression when the conditions are right.

PARALLEL COMPRESSION CONTROL

receiver
2
9
ENG
+030220585 - 1.1 - 10.12.2015