1592001440 XC645CX GB r3.4 31.10.2017.docx XC645CX 29/54
The low superheat pre-alarm warning is sent when the superheat (SH) is lower than ASH2
(low superheat alarm threshold) + ASH0, possibly after the ASH1 delay.
ASH1 Delay for signalling low superheat pre-alarm (0÷255sec)
If the superheat is below the ASH2+ASH0 threshold for ASH1 time the low superheat
pre-alarm warning is sent.
ASH2 Low suction superheat alarm threshold (0.1÷15.0°C/ 1÷30°F). With SH < ASH2 the
low superheat alarm is sent, possibly after the ASH3 delay
ASH3 Delay for signalling low superheat alarm (0÷255sec)
If the superheat is below the ASH2 threshold for ASH3 time the low superheat alarm
message is sent.
ASH4 Switching off compressors with low superheat alarm (No, Yes)
ASH4 = no: compressors keep on working even with low superheat alarm.
ASH4 = yES: compressors are stopped in case of low superheat alarm.
ASH5 Differential to restart regulation after of low superheat alarm with compressor stop
(0.1 to 15.0°C/ 1 to 30°F). In case of regulation stop (ASH4= yES), it restarts when SH >
ASH2+ASH5
ASH6 Delay to restart regulation after superheat > ASH2+ASH5 (0÷255 min). If the
regulation is stopped because of low superheat alarm, it can restart when
SH>ASH2+ASH5 for the ASH6 time.
ASH7 Superheat value to enable hot gas injecting valve (0.1 to 15.0°C/ 1 to 30°F)
With a relay set as hot gas injection valve, (oA2 or oA3 or oA4 = HGi), the relay is on with
SH < ASH7 – ASH8.
ASH8 Differential for ASH7 (0.1 to 30.0°C/ 1 to 60°F)
ASH9 Probe selection for superheat monitoring (nP, P3, P4)
ASH9 = nP no superheat control
ASH9 = P3 the probe to calculate the superheat (SH) is the probe P3 (term. 38-42)
ASH9 = P4 the probe to calculate the superheat (SH) is the probe P4 (term. 22-23). In
this case also the parameter P4C must be set as nt10 or nt86.
17.12 Dynamic set point for fan
dSEP Dynamic set point reference probe
nP = no probe: dynamic set point disabled;
P1= P1 probe
P2= P2 probe
P3= P3 probe
dSES External temperature value to start dynamic regulation (-50÷150°C; -58÷302 °F)
dSEb External band width for dynamic set point (-50.0 ÷ 50.0°C; -90 ÷ 90°F)
dSEd Set point differential for dynamic set point: (-20.0÷20.0°C; -50.0÷50.0PSI; -
300÷300°F)