Emerson XM678D, Operation And Installation Manual

Page: 53 / 76

MODBUS Termination Blocks Default Parameter Map • 45
Atu n
Minimum STABLE
superheat search
No; Yes
This parameter enables the search of the
minimum stable superheat. The lowest
admitted value is LSH+2°C.
AMS n
Self adaptive SH
regulation enabling
No; Yes
This parameter enables the self adaptive
regulation of the superheat. CrE = no
must to be set, when this function is
enabled.
SSH 9 Superheat setpoint
[1°F to 45°F]
[0.1°C to 25.5°C]
This is the value used to regulate the
superheat.
Pb 36 Proportional band
[1°F to 108°F]
[0.1°C to 60.0°C]
The valve changes its opening on the
band
[SSH , SSH + Pb] . At SSH value
of superheat the valve will be at 0%
(without integral contribution) and at
[SSH + Pb] value of superheat the
valve will be at MnF . For values bigger
than [SSH + Pb] the valve is
completely opened.
rS -3
Proportional band
reset
[-12.0°C to 12.0°C]
It allows to move the regulation band,
above or below the SH setpoint.
inC 220
Integration time for
superheat
regulation
0 to 255s -
PEO 0
Valve opening in
case of error on
probes P5 or P6
0 to 100%
If a temporary probe error occurs, valve
opening percentage is PEo until PEd
time is elapsed.
OPE 85
Start opening
percentage for the
time SFD. It’s not
limited by the MnF
parameter.
0 to 100%
Opening valve percentage when the
start function is active. This phase
duration is SFd time.
SFd 0.0
Duration of soft
start phase with
opening at OPE
0.0 to 42min00sec (252)
Set start function duration and post-
defrost duration. During this phase the
alarms are neglected.
Format
: min.10sec

Resolution : 10sec
OPd 85
Valve opening
percentage during
hot gas defrost. It’s
not limited by the
MnF parameter.
0 to 100%
Opening valve percentage during hot
gas defrost. During hot gas defrost there
is no
SH control.
MnF 100
Maximum
percentage of
opening admitted
(during normal
functioning)
0 to 100%
During the regulation it sets the
maximum valve opening percentage.
This value is not used during the SFd
phase (soft start) and during hot gas
defrost, where the fixed percentage of
the valve opening is set by oPd .
Label Value Description Range Notes
Table 24-1 - Default Parameter Map