Emerson XM678D Manual page 11

LABEL VALUE
LSH 2.0 Minimum superheat alarm threshold.
Hysteresis for superheat alarm recovery
SHY 1.0
[MSH – SHY] and [LSH + SHY].
SHd 3.0 Delay of superheat alarm signaling.
Integration
0
FrC
recovery).
Number of pressure values used to
10
Sub
calculate the average pressure
SLb 0.0 Reaction time
tEP nu Predefined valve selection.
tEU bP Kind of valve.
FUL
HSF Kind of motor movement
Minimum number of steps where the valve
LSt 0
can be considered as completely closed.
Maximum number of steps that can be
USt 0
performed.
ESt 0
Extra steps in closing phase
Step rate: is the speed to change step. A
Sr 10
too high value causes a wrong driving.
Current per phase during bipolar valve
0
CPP
driving.
Current per phase to maintain the actual
CHd 0
position (Holding current).
GtH 0.0 Autozero function
REGULATION
SET -5.0
Set point
HY
2 Differential.
Integral
int 150
regulation.
CrE n Continuous regulation activation.
LS -30.0 Minimum set point.
US 20.0
Maximum set point.
odS 0 Outputs activation delay at start up.
AC 0 Anti-short cycle delay.
0.0
CCt Continuous cycle duration.
CCS 0.0
Continuous cycle set point.
Con 15 Compressor ON time with faulty probe.
30
CoF Compressor OFF time with faulty probe.
CF °C Temperature measurement unit.
PrU rE Pressure Mode.
1592023140 XM678D GB r2.8 01.09.2017.docx
DESCRIPTION
additive constant (Fast-
time for room temperature
RANGE
If the superheat value is lower than LSH during the SHd delay time,
then the display will show the message LSH. As soon as the
[0.0°C to MSH]
superheat value is lower than LSH value, the valve will close
[0°F to MSH]
immediately, without waiting the SHd delay time (to avoid
evaporator flooding).
[0.1°C to 25.5°C]
-
[1°F to 45°F]
If a superheat alarm occurs, the delay time SHd will have to expire
0.0 to 42min00sec (252) before the controller shows an alarm.
Format: min.10sec, resolution: 10sec.
It permits to decrease faster the integral action when SH value is
below the set-point.
0 to 100s
With higher values the valve closes faster.
If [FrC = 0] fast recovery function is disabled.
It uses the last average values of the pressure to calculate the
0÷100
superheat.
0 = controller calculates automatically the time to update the valve
0÷255s position.
1÷255s = controller updates valve position every SLb seconds
See par. 6.3.
nU to 10
nU = manual setting.
uP = unipolar valve (5-6 wires);
uP; bP
bP = bipolar valve (4 wires).
HAF = half step. Use this setting for the unipolar valve.
HAF; FUL
FUL = half step. Use this setting for the bipolar valve.
0 to USt (* 10) For manual adjusting of the valve.
LSt to 800 (* 10) For manual adjusting of the valve.
Extra steps done by the valve during closing phase to assure the
0 to 255(*10)
valve closes completely
10 to 600 (steps/sec) For manual adjusting of the valve.
0 to 100 (* 10mA) For manual adjusting of the valve.
0 to 100 (* 10mA) For manual adjusting of the valve.
To prevent any possible wrong position caused by a long period
without closing the valve, the controller after gtH hours, as soon as
0÷15h
the opening open percentage is under 20%, will force complete
closer of the valve, and then will restart working.
LS÷US Target set point for temperature regulation
If [CrE = n] then HY is the hysteresis for ON/OFF thermoregulation.
[0.1°C to 25.5°C] If [CrE = Y] or [CrE = EUP] then HY is the proportional band for
[1°F to 45°F] temperature PI controller. On these cases the value should be
greater than 5°C.
This value is used only when [CrE = Y] or [CrE = EUP]. It's the
integral time for thermoregulation: high values mean slower
0 to 255s
regulation.
0 (zero) = no integral action.
With [CrE = Y] or [CrE = EUP] the regulation become PI, HY
become a band and int an integral time.
n(0); Y(1); EUP(2) n = standard regulation;
Y = continuous regulation, to be used only in centralized plants;
EUP = evaporator valves (see par. 16.2).
[-55.0°C to SET]
Set the minimum acceptable value for the set-point.
[-67°F to SET]
[SET to 150.0°C]
Set the maximum acceptable value for the set-point.
[SET to 302°F]
This function is enabled at the initial start up of the instrument and
0 to 255min inhibits any output activation for the period of time set in this
parameter (N.B.: AUX and Light can work).
0 to 60min Interval between the solenoid valve stop and the following restart.
Compressor ON time during continuous cycle: allows to set the
length of the continuous cycle: compressor stays on without
0.0 to 24h00min (144) interruption for the CCt time. It can be used, for instance, when the
room is filled with new products.
Format: hours.10min, resolution: 10min.
[-55.0°C to 150.0°C] Set point for continuous cycle: used value during the continuous
[-67°F to 302°F] cycle.
Solenoid valve ON time with faulty probe: time during which the
0 to 255min solenoid valve is active in case of faulty thermostat probe. With
COn = 0 solenoid valve is always OFF.
Solenoid valve OFF time with faulty probe: time during which
0 to 255min the solenoid valve is off in case of faulty thermostat probe. With
COF = 0 solenoid valve is always active.
°C = Celsius;
°F = Fahrenheit.
°C(0); °F(1) !!! WARNING !!!
When the measurement unit changes, all parameters with
temperature values will have to be checked.
It defines the mode to evaluate the pressure values.
!!! WARNING !!!
rE(0); Ab(1) PrU value is used for all the pressure parameters. If [PrU = rE] all
pressure parameters are in relative pressure unit, if [PrU = Ab] all
pressure parameters are in absolute pressure unit.
XM678D
NOTES
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