To display and modify target set point; in programming mode it selects a parameter or
In programming mode it browses the parameter codes or increases the displayed
in programming mode it browses the parameter codes or decreases the displayed
BAR
PSI
+
+
LED MODE FUNCTION
AUX ON The auxiliary relay is ON
°C/°F/Bar/PSI
ON
Measurement unit
°C/°F/Bar/PSI
Flashing
Programming phase
1. Push for about 3 seconds th
e
SET
key: the display will show the Set point value;
1. Enter the Programming mode by pressing the SET
and DOWN key for few
CONTROLLERS FOR MULTIPLEXED CABINETS
XM660K- XM669K
CONTENTS
CONTENTS ____________________________________________________________________________ 1
1. GENERAL WARNING ________________________________________________________________ 1
2. GENERAL DESCRIPTION ____________________________________________________________ 1
3. USER INTERFACE __________________________________________________________________ 1
4. FAST ACCESS MENU _______________________________________________________________ 2
5. THE SECTION MENU ________________________________________________________________ 2
6. REAL TIME CLOCK FUNCTIONS (If present) _____________________________________________ 2
7. ELECTRONIC EXPANSION VALVE MENU (ONLY FOR XM669K) _____________________________ 2
8. CONTROLLING LOADS ______________________________________________________________ 2
9. PARAMETER LIST __________________________________________________________________ 3
10. DIGITAL INPUTS ___________________________________________________________________ 5
11. INSTALLATION AND MOUNTING ______________________________________________________ 5
12. ELECTRICAL CONNECTIONS _________________________________________________________ 5
13. RS485 SERIAL LINE _________________________________________________________________ 6
14. USE OF THE PROGRAMMING “HOT KEY“ _______________________________________________ 6
15. ALARM SIGNALS ___________________________________________________________________ 6
16. TECHNICAL DATA __________________________________________________________________ 6
17. CONNECTIONS ____________________________________________________________________ 6
18. DEFAULT SETTING VALUES _________________________________________________________ 6
1. GENERAL WARNING
1.1
• This manual is part of the product and should be kept near the instrument for easy and quick
• The instrument shall not be used for purposes different from those described hereunder. It cannot
• Check the application limits before proceeding.
•
1.2
• Check the supply voltage is correct before connecting the instrument.
• Do not expose to water or moisture: use the controller only within the operating limits avoiding
• Warning: disconnect all electrical connections before any kind of maintenance.
• Fit the probe where it is not accessible by the End User. The instrument must not be opened.
• In case of failure or faulty operation send the instrument back to the distributor or to “Dixell S.r.l.”
• Consider the maximum current which can be applied to each relay (see Technical Data).
• Ensure that the wires for probes, loads and the power supply are separated and far enough from
• In case of applications in industrial environments, the use of mains filters (our mod. FT1) in parallel
2. GENERAL DESCRIPTION
The XM660K/XM669K are high level microprocessor based controllers for multiplexed cabinets suitable
for applications on medium or low temperature. It can be inserted in a LAN of up to 8 different sections
which can operate, depending on the programming, as stand alone controllers or following the
commands coming from the other sections. The XM660K/XM669K are provided with 4 relay outputs to
control the solenoid valve, defrost - which can be either electrical or hot gas - the evaporator fans, the
lights and with one output to drive pulsed electronic expansion valves (only XM669K). The devices
are also provided with four probe inputs, one for temperature control, one to control the defrost end
temperature of the evaporator, the third for the display and the fourth can be used for application with
virtual probe or for inlet/outlet air temperature measurement. The model XM669K is provided by other
two probes that have to be used for superheat measurement and regulation. Finally, the
XM660K/XM669K are equipped with two digital inputs (free contact) fully configurable by parameters.
The instruments are equipped with the HOTKEY connector that permits to be programmed in a simple
way. Direct serial output RS485 ModBUS-RTU compatible permits a simple XWEB interfacing. RTC
are available as options. The HOTKEY connector can be used to connect X-REP display (Depending on
the model).
3. USER INTERFACE
PLEASE READ BEFORE USING THIS MANUAL
reference.
be used as a safety device.
Dixell Srl reserves the right to change the composition of its products, even without notice,
ensuring the same and unchanged functionality.
SAFETY PRECAUTIONS
sudden temperature changes with high atmospheric humidity to prevent formation of
condensation
(see address) with a detailed description of the fault.
each other, without crossing or intertwining.
with inductive loads could be useful.
confirm an operation.
By holding it pressed for 3s when max or min temperature is displayed it will be
erased.
value.
By holding it pressed for 3s the give access to the “Section” menu.
By pressing and releasing this key you get the access to fast access menu
value.
By pressing and releasing this key you can activate or deactivate the auxiliary output
By holding it pressed for 3s the defrost is started.
KEY COMBINATIONS
3.1 USE OF LEDS
Each LED function is described in the following table.
3.2 HOW TO ENTER INTO FAST ACCESS MENU
3.3 HOW TO SEE THE MAX AND MIN TEMPERATURE RECORDED
3.4 HOW TO SEE AND MODIFY THE SET POINT
3.5 HOW TO START A MANUAL DEFROST
3.6 TO ENTER IN PARAMETERS LIST “PR1”
To enter the parameter list “Pr1” (user accessible parameters) operate as follows:
3.7 TO ENTER IN PARAMETERS LIST “PR2”
To access parameters in “Pr2”:
1. Enter the “Pr1” level.
2. Select “Pr2” parameter and press the “SET” key.
3. The “PAS” flashing message is displayed, shortly followed by “0 - -” with a flashing zero.
4. Use oor n to input the security code in the flashing digit; confirm the figure by pressing “SET”. The
security code is “321“.
5. If the security code is correct the access to “Pr2” is enabled by pressing “SET” on the last digit.
Another possibility is the following: after switching ON the instrument the user can push Set and DOWN
keys within 30 seconds.
Switch ON and OFF the room light.
By pressing for about 3s switch ON and OFF the instrument.
Measurement unit
Measurement unit
Measurement unit
Measurement unit
+
ON
Flashing Anti-short cycle delay enabled
ON Defrost enabled
Flashing Drip time in progress
ON An alarm is occurring
ON Energy saving enabled
ON The fan is running
Flashing Door opened or delay to restart fan after defrost
ON The controller is working in “ALL” mode
Flashing The controller is working in remote virtual display mode
Flashing During the CLOCK modification (if clock is present)
1. Press and release the o key.
2. First Label will be displayed. By pressing the o or n keys it’s possible to navigate
the menu
1. Press and release the o key.
2. First Label will be displayed. By pressing the o or n keys it’s possible to navigate
the menu. Search the L°t label and press SET to see minimum temperature; search
the H°t label and press SET to see maximum temperature;
2. The measurement unit starts blinking;
3. To change the Set value push the o or n arrows within 10s.
4. To store the new set point value push the SET key again or wait 10s.
Push the DEF key for more than 3 seconds and a manual defrost will start.
SET
+
2. The instrument will show the first parameter present in “Pr1”
To lock and unlock the keyboard.
To enter the programming mode.
To exit the programming mode.
Compressor and valve regulation enabled, to see valve opening
percentage you should see the fast access menu
seconds (measurement unit starts blinking).
1592023020 XM660K_XM669K GB r1.0 07.01.2013.doc XM660K - XM669K 1/8
By pushing the
ON/OFF
key, the instrument shows “OFF”. During the OFF status, all the
1. En
ter the Programming mode by pressing the SET and DOWN key for few
1. Enter the Programming mode by pressing the SET and DOWN key for few
NOTE: each parameter in “Pr2” can be removed or put into “Pr1” (user level) by pressing “SET” + n.
When a parameter is present in “Pr1” LED is on.
3.8 HOW TO CHANGE THE PARAMETER VALUE
1. Enter the Programming mode.
2. Select the required parameter with o or n.
3. Press the “SET” key to display its value (measurement unit starts blinking).
4. Use o or n to change its value.
5. Press “SET” to store the new value and move to the following parameter.
To exit: Press SET + UP or wait 15s without pressing a key.
NOTE: the new programming is stored even when the procedure is exited by waiting the time-out.
3.9 ON/OFF FUNCTION
relays are switched OFF and the regulations are stopped; if a monitoring system is
connected, it does not record the instrument data and alarms.
N.B. During the OFF status the Light and AUX buttons are active.
4. FAST ACCESS MENU
FAST ACCESS MENU
HM Fast access to Clock settings; (if present)
An Fast access to analog output reading; (if present)
SH Superheat: shows the actual superheat value; (Only XM669K)
oPP Valve opening percentage: shows actual opening percentage of the valve; (Only XM669K)
dP1 Probe 1 value displaying shows the temperature measured by probe 1;
dP2 Probe 2 value displaying shows the temperature measured by probe 2;
dP3 Probe 3 value displaying shows the temperature measured by probe 3;
dp4 Probe 4 value displaying shows the temperature measured by probe 4;
dP5 Probe value displaying shows the temperature value measured by probe 5; (Only XM669K)
dP6 Probe 6 value displaying shows the temperature measured by probe 6; (Only XM669K)
dPP Pressure probe value shows the value of pressure measured by pressure transducer; (Only
XM669K)
rPP Remote pressure probe value show the value of pressure received by remote pressure probe
connected to other XM600K device; (Only XM669K)
L°t minimum measured temperature shows the minimum temperature read by the regulation probe;
H°t Maximum measured temperature shows the maximum temperature read by the regulation
probe;
dPr Virtual regulation probe value shows the value measured by virtual regulation probe;
dPd Virtual defrost probe value shows the value measured by virtual defrost probe;
dPF Virtual fans probe value shows the value measured by virtual fan probe;
rSE Real set point: shows the set point used during the energy saving cycle or during the continuous
cycle.
5. THE SECTION MENU
This menu allows the user to access to a particular feature of the XM series related to the LAN (Local
Area Network) of controllers. A single keyboard, depending on the programming of this menu, is able to
control either the module of the local section of the LAN or ALL. The possibilities are: LOC: the
keyboard controls and display the value, the status and the alarms of the local section of the LAN; ALL:
the command given by the keyboard are effective on all the sections of the LAN.
1. Push the o key for more than 3 seconds
2. The label corresponding to the section controlled by the keyboard will be displayed.
3. With o or n key select the section you want to control.
4. Press “Set” key to confirm and exit
6. REAL TIME CLOCK FUNCTIONS (IF PRESENT)
The following functions are available only if the Real Time Clock is present. To get access to real time
clock submenu:
SET
+
6.1 TO SET CURRENT TIME AND DAY
Hur Current hour (0 ÷ 23 h)
Min Current minute (0 ÷ 59min)
dAY Current day (Sun ÷ SAt)
Hd1 First weekly holiday (Sun ÷ nu) Set the first day of the week which follows the holiday times.
Hd2 Second weekly holiday (Sun ÷ nu) Set the second day of the week which follows the holiday
times.
Hd3 Third weekly holiday (Sun ÷ nu) Set the third day of the week which follows the holiday times.
N.B. Hd1,Hd2,Hd3 can be set also as “nu” value (Not Used).
6.2 TO SET ENERGY SAVING TIMES
ILE Energy Saving cycle start during workdays: (0 ÷ 23h 50 min.) During the Energy Saving cycle
the set point is increased by the value in HES so that the operation set point is SET + HES.
dLE Energy Saving cycle length during workdays: (0 ÷ 24h 00 min.) Sets the duration of the Energy
Saving cycle on workdays.
ISE Energy Saving cycle start on holidays. (0 ÷ 23h 50 min.)
dSE Energy Saving cycle length on holidays (0 ÷ 24h 00 min.)
HES Temperature increase during the Energy Saving cycle (-30÷30°C / -54÷54°F) sets the
increasing value of the set point during the Energy Saving cycle.
seconds (measurement unit starts blinking).
2. The instrument will show RTC label;
3. Press SET. You are in RTC function menu;
6.3 TO SET TIMED DEFROST PARAMETERS
Ld1÷Ld6 Workday defrost start (0 ÷ 23h 50 min.) These parameters set the beginning of the eight
programmable defrost cycles during workdays. Ex. When Ld2 = 12.4 the second defrost starts at
12.40 during workdays.
Sd1÷Sd6 Holiday defrost start (0 ÷ 23h 50 min.) These parameters set the beginning of the eight
programmable defrost cycles on holidays. Ex. When Sd2 = 3.4 the second defrost starts at 3.40 on
holidays.
To disable a defrost cycle set it to “nu”(not used). Ex. If Ld6=nu ; the sixth defrost cycle is
disabled
7. ELECTRONIC EXPANSION VALVE MENU (ONLY FOR XM669K)
+
SET
seconds (measurement unit starts blinking).
2. Press arrows until the instrument shows EEU label;
3. Press SET. You are now in EEV function menu.
8. CONTROLLING LOADS
8.1 THE SOLENOID VALVE
The regulation is performed according to the temperature measured by the thermostat probe that can be
physical probe or virtual probe obtained by a weighted average between two probes (see parameters
table description) with a positive differential from the set point. If the temperature increases and reaches
set point plus differential the solenoid valve is opened and then it is closed when the temperature
reaches the set point value again.
In case of fault in the thermostat probe the opening and closing time of solenoid valve is configured by
“Con” and “CoF” parameters.
8.2 STANDARD REGULATION AND CONTINUOUS REGULATION
The regulation can be performed in two ways: the goal of the first way (standard regulation) is
reaching the best superheat via a classic temperature regulation obtained using hysteresis. The second
way, permits to use the valve to realise an high performance temperature regulation with a good factor
of superheat precision. This second possibility, it can be used only in centralized plants and it is
available only with electronic expansion valve by selecting CrE=Y parameter.
In any case, the regulation is performed via PI regulator that gives the opening percentage to the valve
via PWM modulation explained as follow. Opening percentage is obtained from average of Opening
Time respect to CyP time period like following diagram:
With opening percentage we mean percentage of cycle period where valve is open. For example, if
CyP=6s (standard value) by saying: “The valve is opened at 50%”; this means that the valve is opened
for 3s during cycle period.
First kind of regulation:
In this case, the Hy parameter is the differential for standard ON/OFF regulation. In this case the int
parameter is neglected. The regulation follow this diagram:
Second kind of regulation – Continuous regulation (only XM669K):
In this case, the Hy parameter is the proportional band of PI in charge of room temperature regulation
and we advise to used at least Hy=5.0°C/10°F. The int parameter is the integral time of the same PI
regulator. Increasing int parameter the PI regulator become slow in reaction and of course is true vice
versa. To disable the integral part of regulation you should set int=0.
8.3 DEFROST
Defrost starting
In any case, the device check the temperature read by configured defrost probe before starting
defrost procedure, after that:
1592023020 XM660K_XM669K GB r1.0 07.01.2013.doc XM660K - XM669K 2/8
The modulating output (
trA=rEG
) works in
- (If RTC is present)Two defrost modes are available through the “tdF” parameter: defrost with
electrical heater and hot gas defrost. The defrost interval is controlled by parameter “EdF”: (EdF =
rtc) defrost is made in real time depending on the hours set in the parameters Ld1..Ld6 in workdays
and in Sd1…Sd6 on holidays; (EdF = in) the defrost is made every “IdF” time;
- defrost cycle starting can be operated locally (manual activation by means of the keyboard or digital
input or end of interval time) or the command can come from the Master defrost unit of the LAN. In
this case the controller will operate the defrost cycle following the parameters it has programmed but,
at the end of the drip time, will wait that all the other controllers of the LAN finish their defrost cycle
before to re-start the normal regulation of the temperature according to dEM parameter;
- Every time any of the controller of the LAN begin a defrost cycle it issue the command into the
network making all the other controllers start their own cycle. This allows a perfect synchronisation of
the defrost in the whole multiplexed cabinet according to LMd parameter;
- Selecting dPA and dPb probes and by changing the dtP and ddP parameters the defrost can be
started when the difference between dPA and dPb probes is lower than dtP for all ddP time. This is
useful to start defrost when a low thermal exchange is detected. If ddP=0 this function is disabled;
Defrost ending
- When defrost is started via rtc, the maximum duration of defrost is obtained from Md parameter and
the defrost end temperature is obtained from dtE parameter (and dtS if two defrost probes are
selected).
- If dPA and dPb are present and d2P=y the instrument stops the defrost procedure when dPA is
higher than dtE temperature and dPb is higher than dtS temperature;
At the end of defrost the drip time is controlled through the “Fdt” parameter.
8.4 FANS
CONTROL WITH RELAY
The fan control mode is selected by means of the “FnC” parameter:
C-n = running with the solenoid valve, OFF during the defrost;
C-y = running with th1e solenoid valve, ON during the defrost;
O-n = continuous mode, OFF during the defrost;
O-y = continuous mode, ON during the defrost;
An additional parameter “FSt” provides the setting of temperature, detected by the evaporator probe,
above which the fans are always OFF. This can be used to make sure circulation of air only if his
temperature is lower than set in “FSt”.
CONTROL WITH ANALOG OUTPUT (if present)
proportional way (excluding the first AMt
seconds where the fans speed is the maximum).
The regulation set point is relative to regulation
set point and is indicated by ASr, the
proportional band is always located above
SET+ASr value and its value is PbA. The fan are
at minimum speed (AMi) when the temperature
read by fan probe is SET+ASr and the fan is at
maximum speed (AMA) when the temperature is
SET+ASr+PbA.
8.5 ANTI SWEAT HEATERS (IF PRESENT)
This control is performed when trA=AC. In this case, there is two way to control the anti-sweat heaters:
• Without real dew-point information: in this case the default value for dew-point is used
(SdP parameter).
• Receiving dew-point from XWEB5000 system: the SdP parameter is overwrote when valid
value for dew-point is received from XWEB.
The P4 probe is used to perform the regulation
and it should be placed on the showcase glass.
In case of P4 error or if P4 is absent the output is
at AMA value for the AMt time then the output is
at 0 value for the time 255-AMt time performing
a simple PWM modulation.
9. PARAMETER LIST
REGULATION
rtC Access to CLOCK submenu (if present);
EEU Access to EEV submenu (only XM669K);
Hy Differential: (0,1÷25,5°C; 1÷45°F): Intervention differential for set point, always positive.
Solenoid valve Cut IN is Set Point Plus Differential (Hy). Solenoid valve Cut OUT is when the
temperature reaches the set point.
Int Integral time for room temperature regulation (Only XM669K): (0 ÷ 255 s) integral time for
room temperature PI regulator. 0= no integral action;
CrE Continuous regulation activation (Only XM669K): (n÷Y) n= standard regulation; Y=
continuous regulation. Use it only in centralized plants;
LS Minimum set point limit: (-55.0°C
the set point.
US Maximum set point limit: (SET
set point.
OdS Outputs activation delay at start up: (0÷255 min) This function is enabled at the initial start
up of the instrument and inhibits any output activation for the period of time set in the
parameter. (AUX and Light can work)
AC Anti-short cycle delay: (0÷60 min) interval between the solenoid valve stop and the following
restart.
CCt Compressor ON time during continuous cycle: (0.0÷24.0h; resolution 10min) Allows to set
the length of the continuous cycle: compressor stays on without interruption for the CCt time.
Can be used, for instance, when the room is filled with new products.
÷÷÷÷
SET; -67°F÷SET) Sets the minimum acceptable value for
÷÷÷÷
150°C; SET÷302°F) Set the maximum acceptable value for
CCS Set point for continuous cycle: (-55÷150°C / -67÷302°F) it sets the set point used during the
continuous cycle.
Con solenoid valve ON time with faulty probe: (0÷255 min) time during which the solenoid valve
is active in case of faulty thermostat probe. With COn=0 solenoid valve is always OFF.
CoF solenoid valve OFF time with faulty probe: (0÷255 min) time during which the solenoid valve
is off in case of faulty thermostat probe. With COF=0 solenoid valve is always active.
DISPLAY
CF Temperature measurement unit: °C=Celsius; °F=Fahrenheit. !!! WARNING !!! When the
measurement unit is changed the parameters with temperature values have to be checked.
PrU Pressure mode: (rEL or AbS) it defines the mode to use the pressure. !!! WARNING !!! the
setting of PrU is used for all the pressure parameters. If PrU=rEL all pressure parameters are in
relative pressure unit, if PrU=AbS all pressure parameters are in absolute pressure unit. (Only
XM669K)
PMU Pressure measurement unit: (bAr – PSI - MPA) it selects the pressure measurement units.
MPA= the value of pressure measured by kPA*10. (Only XM669K)
PMd Way of displaying pressure : (tEM - PrE) it permits showing the value measured by pressure
probe with tEM= temperature or by PrE= pressure; (Only XM669K)
rES Resolution (for °C): (in = 1°C; dE = 0.1 °C) allows decimal point display;
Lod Instrument display: (nP; P1; P2, P3, P4, P5, P6, tEr, dEF) it selects which probe is displayed
by the instrument. P1, P2, P3, P4, P5, P6, tEr= virtual probe for thermostat, dEF= virtual probe
for defrost.
red Remote display: (nP; P1; P2, P3, P4, P5, P6, tEr, dEF) it selects which probe is displayed by
the X-REP. P1, P2, P3, P4, P5, P6, tEr= virtual probe for thermostat, dEF= virtual probe for
defrost.
dLy Display delay: (0 ÷24.0 m; resolution 10s) when the temperature increases, the display is
updated of 1 °C/1°F after this time.
rPA Regulation probe A: (nP; P1; P2, P3, P4, P5) first probe used to regulate room temperature. If
rPA=nP the regulation is performed with real value of rPb.
rPb Regulation probe B: (nP; P1; P2, P3, P4, P5) second probe used to regulate room
temperature. If rPb=nP the regulation is performed with real value of rPA
rPE Regulation virtual probe percentage: (0 ÷ 100%) it defines the percentage of the rPA respect
to rPb. The value used to regulate room temperature is obtained by:
ELECTRONIC EXPANSION VALVE SUBMENU (Only XM669K)
FtY Kind of gas (R22, 134, 404, 407, 410, 507,CO2): Type of gas used by plant. Fundamental
value_for_room = (rPA*rPE + rPb*(100-rPE))/100
parameter for correct functioning of all system.
SSH Superheat set point: [0.1°C ÷ 25.5°C] [1°F ÷ 45°F] it’s the value used to regulate superheat
CyP Cycle Period: (1 ÷ 15s) it permits to set cycle time;
Pb Proportional band: (0.1 ÷ 60.0 / 1÷108°F) PI proportional band;
rS Band Offset: (-12.0 ÷ 12.0°C / -21÷21°F) PI band offset;
inC Integration time: (0 ÷ 255s) PI integration time;
PEO Probe Error opening percentage: (0÷100%) if a temporary probe error occurs, valve opening
percentage is PEo until PEd time is elapsed;
PEd Probe Error delay before stopping regulation: (0÷239 sec. – On=unlimited) if probe error
duration is bigger than PEd then valve totally closes. Pf message is showed. If PEd=On valve
opening is PEo until probe error finishes;
OPE Start opening Percentage: (0÷100%) Opening valve percentage when start function is active.
This phase duration is SFd time;
SFd Start Function duration: (0.0 ÷ 42.0 min: resolution 10s) It sets start function duration and
post-defrost duration. During this phase the alarms are neglected;
OPd Opening Percentage after defrost phase: (0÷100%) Opening valve percentage when after
defrost function is active. This phase duration is Pdd time;
Pdd Post Defrost Function duration: (0.0 ÷ 42.0 min: resolution 10s) It sets start function duration
and post-defrost duration. During this phase the alarms are neglected;
MnF Maximum opening percentage at normal Functioning: (0÷100%) during regulation it sets
the maximum valve opening percentage;
dCL Delay before stopping valve regulation: (0 ÷ 255s) When the cooling request goes off, the
electronic valve regulation can go on for the dCL time in order to prevent uncontrolled
superheat variation;
Fot Forced opening percentage: (0÷100% - nu) it permits to force the valve opening to the
specified value. This value overwrite the value calculated by PID algorithm. !!!! WARNING !!!!
to obtain the correct superheat regulation you have to set Fot=nu;
tPP Type of Pressure Transducer: (PP – LAn) it sets type of pressure transducer to use: PP=
4÷20mA pressure transducer or ratiometric transducer 0÷5V depending on P5C parameter,
LAn= the pressure signal arrives from another XM600K; Referred to Pb5
PA4 Probe value At 4mA or At 0V: (-1.0 ÷ P20 bar / -14 ÷ PSI / -10 ÷ P20 kPA*10) pressure value
measured by probe at 4mA or at 0V (related to PrM parameter) Referred to Pb5
P20 Probe value 20mA or At 5V: (PA4 ÷ 50.0 bar / 725 psi / 500 kPA*10) pressure value
measured by probe at 20mA or at 5V (related to PrM parameter) Referred to Pb5
LPL Lower Pressure Limit for superheat regulation: (PA4 ÷ P20 bar / psi / kPA*10) when suction
pressure comes down to LPL the regulation is performed with a LPL fixed value for pressure,
when pressure comes back to LPL the normal pressure value is used. (related to PrM
parameter)
MOP Maximum Operating Pressure threshold: (PA4 ÷ P20 bar / psi / kPA*10) if suction pressure
exceeds maximum operating pressure value, instrument signals situation with MOP alarm.
(related to PrM parameter)
LOP Lowest Operating Pressure threshold: (PA4 ÷ P20 bar / psi / kPA*10) if the suction pressure
comes down to this value a low pressure alarm is signalled with LOP alarm. (related to PrM
parameter)
dML delta MOP-LOP: (0 ÷ 100%) when a MOP alarm occurs valve will close of the dML percentage
every cycle period until MOP alarm is active. When LOP occurs valve will open of the dML
percentage every cycle period until LOP alarm is active.
MSH Maximum Superheat alarm: (LSH ÷ 80.0°C / LSH ÷ 144°F) when superheat exceeds this
value an high superheat alarm is signalled after interval SHd
LSH Lowest Superheat alarm: (0.0 ÷ MSH °C / 0÷MSH °F) when superheat goes down to this
value a low superheat alarm is signalled after interval SHd
SHy Superheat alarm Hysteresis: (0.1÷25.5°C/1÷45°F) hysteresis for superheat alarm
deactivation
1592023020 XM660K_XM669K GB r1.0 07.01.2013.doc XM660K - XM669K 3/8
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