Emerson Dixell XC645CX User Manual

1592001440 XC645CX GB r3.4 31.10.2017.docx XC645CX 26/54
17.5 Compressor regulation
Pbd: Proportional band or neutral zone width (0.1÷5.0bar/0.5÷30°C or 1÷150PSI/1÷50°F)
The band (or zone) is symmetrical compared to the target set point, with extremes: set-
Pbd/2 ÷ set+Pbd/2. It is used as proportional band for PI algorithm.
The measurement unit depends on the dEU, CF, PMU par.
rS Proportional band offset: PI band offset. It permits to move the proportional band of the
PI. With rS=0 the band is between Set-Pbd/2 ÷ Set+Pbd/2;
inC Integration time: (0 ÷ 999s) PI integration time
dGSP Digital compressor always activated at first:
no: other compressors if available are allowed to start when the digital compressor is
locked by safety timers. This allows the system to satisfy the cooling demand when the
digital compressor is unavailable.
yES: the digital compressor is always started as first. If unavailable due to safety timers
the regulation will be locked till timers will be over.
SUt Start up time: The digital scroll valve is energized for the SUt when the compressor starts
(0÷3s)
tdS Digital scroll cycle time: (10÷40s) it sets the cycle time for the digital scroll (DGS) valve
modulation.
PM DGS minimum capacity (10÷PMA with dGty=ScrL; 0÷PMA = dGty=StrM): it sets the
minimum capacity allowed to the digital compressor.
If digital SCROLL is used dGt = SCrL the allowed range is 10÷PMA
If digital STREAM is used dGt = StrM the allowed range is 0÷PMA
PMA DGS maximum power (PM÷100) it sets the maximum capacity allowed to the DGS
ton DGS at maximum PMA capacity before starting a new load (0÷255s)
toF DGS at minimum PM capacity before stopping a load (0÷255s)
MinP Minimum allowed DGS capacity for poor lubrication monitoring (0÷100%; with 0
function excluded) If the DGS compressor works for the tMIn time with a capacity (in
percentage) equal or lower than MinP, it is forced to work at 100% for the tMAS time in
order to restore the right lubrication.
tMin Maximum DGS functioning time at a capacity lower than MinP, before working at
full capacity (PMA) (1÷255min)
tMAS Time of DGS functioning at maximum capacity (PMA) to restore the right
lubrication (1÷255min)
ESC Energy saving value for compressors: (-20÷20bar; -50÷50°C) this value is add to the
compressor set point.
onon: Minimum time between 2 following switching ON of the same compressor (0÷255
min).
oFon: Minimum time between the switching off of a compressor and the following
switching on. (0÷255min). Note: usually onon is greater than oFon.
don: Time delay between the insertion of two different compressors (0÷99.5min; res.
10s).
doF: Time delay between switching off of two different compressors (0÷99.5 min; res.
10s)
donF: Minimum time a stage stays switched ON (0÷99.5 min; res. 10s)
Maon Maximum time for compressor ON (0 ÷ 24 h; with 0 this function is disabled.) If a
compressor keeps staying on for the MAon time, it’s switched off and it can restart after
the oFon standard time.
FdLy: “don” delay enabled also for the first call. If enabled, the triggering of the step is delayed
for a “don” value, respect to the call. (no = “don” not enabled; yES=”don” enabled)
FdLF “doF” delay enabled also for the first switching off. It enables the “doF” delay between
the request of a release and the actual switching off. (no = “doF” not enabled;
yES=”doF” enabled)
odo: Regulation delay on start-up: (0÷255s) on switching ON the instrument starts working
after the time delay imposed in this parameter.

Emerson Dixell XC645CX Specifications

General

Brand	Emerson
Model	Dixell XC645CX
Category	Controller
Language	English