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FoP
Forced Opening percentage: (0 to 100; nU) if FoP=nU valve works with regulation
algorithm. If FoP is different from nU the valve stays at FoP opening percentage. This
function could be useful during plant starting or during service operations.
PID PARAMETERS (trained staff)
Pb
Proportional band in chill
mode:
(0.1 to 50.0°C; 1 to 90°F)
PI proportional band. A value
bigger than 5°C is advised.
rS
Band Offset:
(-12.0 to 12.0°C; -21 to 21°F)
PI band offset. It permits to
move the proportional band of
the PI. With rS=0 the band is
between [SEt to SEt+Pb].
inC
Integration time in chill mode: (0 to 255s) PI integration time.
dFc
Derivative time in chill mode: (0 to 255s) PID derivative time.
Pb2
Proportional band in heat-pump mode:
(0.1 to 50.0°C; 1 to 90°F)
PI proportional band. A value bigger than 5°C is advised.
it2
Integration time in heat-pump mode: (0 to 255s) PI integration time.
dt2
Derivative time in heat-pump mode : (0 to 255s) PID derivative time.
db
Dead band: (0.0 ÷ 25.5 °C; 0 ÷ 45°F) if the superheat is inside the band SH-db/2÷
SH+db/2 the position of the valve is not updated
PROBE PARAMETERS
tPP
Type of Pressure transducer: (420; 5V) it sets type of pressure transducer to use. 420
= 4 to 20mA pressure transducer; 5V = 0 to 5V ratiometric transducer.
PA4
Probe value at 4mA or at 0V: (-1.0 to P20 bar; -14 to P20 psi) pressure value
measured by probe at 4mA or at 0V (related to PrM parameter).
P20
Probe value at 20mA or at 5V: (PA4 to 50.0 bar; PA4 to 725 psi) pressure value
measured by probe at 20mA or at 5V (related to PrM parameter).
oPr
Pressure probe calibration: -12.0 to 12.0 bar; -174 to 174 psi.
ttE
Type of temperature probe: (PtM; ntC) it allows to set the kind of probe used by the
instrument: PtM = PT1000 probe, ntC = NTC-US probe.
otE
Temperature probe calibration: -12.0 to 12.0°C; -21 to 21°F.
DIGITAL INPUTS
i1P
Digital Input 1 (Free of voltage) digital input polarity: (cL, oP) CL = activated when
closed; oP = activated when opened.
i1F
Digital Input 1 (Free of voltage) digital input function: (CCL, rL)
-
CCL = cooling call;
rL = digital input activates relay.
-
d1d
Digital Input 1 (Free of voltage) activation delay: (0 to 255 min) this activation delay is
used only if digital input is configured as rL.
i2P
Digital Input 2 (Free of voltage) digital input polarity: (CL, oP) CL = activated when
closed; oP = activated when opened.
i2F
Digital Input 2 (Free of voltage) digital input function: (CCL, P-C)
-
CCL = cooling call;
-
P-C = Switch form chiller to heat pump mode.
d2d
Digital Input 2 (High voltage) activation delay: (0 to 255 min) this activation delay is
used only if digital input is configured as rL.
ALARM
dAo
Alarm delay after restarting regulation: (0.0 to 42min 00s, res. 10s) time between
digital input activation (configured as CCL) and alarm signalling. The LSH alarm is
always signalled also during this time.
tdA
Type of alarm signalled by relay: (ALL, SH, PrE, di) ALL = all alarm; SH = superheat
alarm; PrE = pressure alarm; di = activation only when digital input configured as rL is
active.
LPL
Lower Pressure Limit for superheat regulation: (PA4 to P20 bar; PA4 to P20 psi)
when suction pressure comes down to LPL, the regulation is performed with a LPL fixed
value for pressure. When suction pressure comes back to LPL, the normal pressure
value is used (related to PrM parameter).
MoP
Maximum Operating Pressure threshold: (LoP to P20bar; LoP to P20 psi) if suction
pressure exceeds maximum operating pressure value, the instrument signals this
situation with an alarm LED
LoP
Lowest Operating Pressure: (PA4 to MoP bar; PA4 to MoP psi) if the suction pressure
comes down to this value, a low pressure alarm will be signalled with an alarm LED
(related to PrM parameter).
PHY
Pressure alarm Hysteresis: (0.1 to 5.0 bar, 1 to 72 psi) pressure hysteresis to disable
alarm signalling.
dML
Delta MoP-LoP: (0 to 100%) when a MoP alarm occurs valve will close of the dML
percentage every one second until MoP alarm is active. When LoP occurs, valve will
open of the dML percentage every one second until LoP alarm is active.
MSH
Maximum SuperHeat alarm: (LSH to 80.0°C; LSH to 144°F) when superheat exceeds
this value, an high superheat alarm will be signalled after interval SHd.
LSH
Lowest SuperHeat alarm: (0.0 to MSH°C; 0 to MSH°F) when superheat goes down to
this value a low superheat alarm is signalled after interval SHd.
1592025930 XEV23D GB r1.0 07.10.2011.doc
(related to PrM parameter).
SHY
SuperHeat alarm Hysteresis: (0.0 to 25.5°C; 1 to 77°F) hysteresis for superheat alarm
deactivation.
SHd
SuperHeat alarm activation delay: (0 to 255 s) when a superheat alarm occurs, the
delay time SHd have to expire before signalling this alarm.
FrC
Fast-recovery Constant: (0 to 100 s) permits to increase integral time when SH is
below the set-point. If FrC=0 fast recovery function is disabled.
DISPLAY
Lod
Local display: (SH; PEr; P1; P2) SH = superheat; PEr = valve opening percentage;
P1 = value of temperature measured; P2 = pressure measured by P2 probe.
CF
Temperature measurement units: (°C; °F) °C = Celsius degree; °F = Fahrenheit
degree. NOTE: by changing measurement unit, the regulation parameters have to be
correctly changed.
PMU
Pressure Measurement units: (bAr, PSi) bAr = bar; PSi = psi. NOTE: by changing
measurement unit, the regulation parameters have to be correctly changed.
rES
Resolution (only °C): (dE; in) dE = decimal format; in = integer format.
PrM
Pressure visualization Mode: (rEL; AbS) rEL = relative pressure; AbS = absolute
pressure. All pressure parameters depend on this parameter.
CLP
Cooling Percentage (read only): Display the cooling percentage.
tP1
Temperature Probe value (read only): it shows temperature probe value from P1.
PPr
Pressure probe value (read only): it shows pressure probe value. The value depends
on PrM.
tP2
Temperature from P2 (read only): it shows temperature obtained from conversion of
pressure value.
oPP
Opening Percentage (read only): it shows the actual opening percentage of the valve.
d1S
Free of voltage digital input State (read only): it shows the free of voltage digital input.
d2S
High voltage digital input State (read only): it shows the high voltage digital input
state.
Mod
ModBus: (AdU; Std) AdU = (Only for XWEB systems) in this case XEV and
thermostatic controller are considered an alone instrument (it requires a custom library
for XWEB); Std = to use XEV in stand-alone mode, in this case normal Modbus-RTU
protocol is used.
Adr
RS485 Serial Address: (1 to 247) Identifies the instrument address when connected to a
ModBUS compatible monitoring system.
Ptb
Parameters map: (read only) it identifies parameters map written by factory.
rEL
Release Firmware: (read only) it shows firmware release.
Pr2
Second level menu.
9. DIGITAL INPUTS
The device is provided with two digital inputs.
The first one (13-15) is free of voltage and is used to enable the regulation
The second one (8-9) is free of voltage and is used to switch form chiller to heat-pump mode.
One of these inputs must be configured as cooling call.
10. FORCED OPENING
If necessary, by changing FoP parameter it's possible to force the valve opening. For example, by
setting FoP=50 the valve will be open at half of full scale. To disable this function it's necessary to
set FoP=nU (default value). The valve opening is enabled only when CCL digital input is enabled.
11. ELECTRICAL CONNECTIONS
The instrument is provided with pluggable screw terminal block to connect cables with a cross section
up to 2.5 mm
. Heat-resistant cables have to be used. Before connecting cables make sure the power
2
supply complies with the instrument's requirements. Separate the probe cables from the power supply
cables, from the outputs and the power connections. Do not exceed the maximum current allowed on
each relay, in case of heavier loads use a suitable external relay.
11.1 PROBES
Temperature probe placement: between hour 3 and 9 respect to horizontal pipe section. For suction
pressure probe there aren't any particular prescriptions
12. RS485 SERIAL LINE
All models can be connected to the monitoring and supervising system XWEB3000. If Mod=Std
standard ModBUS-RTU protocol is used, if Mod=AdU custom XWEB library is required. This last
configuration makes possible to use the same serial address of the thermostat that gives the cooling
request to XEV. In this way, it's possible to reduce the number of addresses used.
13. HOW TO: USE THE HOT-KEY
13.1 PROGRAM A HOT-KEY FROM THE INSTRUMENT (UPLOAD)
1)
Program one controller with the front keypad.
2)
When the controller is ON, insert the HOT-KEY and push UP button; the "uPL" message
appears followed a by flashing "End".
3)
Push SET button and the "End" will stop flashing.
Turn OFF the instrument, remove the HOT-KEY and then turn it ON again.
4)
NOTE: the "Err" message is displayed in case of any failed programming operation. In this case, push
again UP button if you want to restart the upload again or remove the HOT-KEY to abort the operation.
13.2 PROGRAM AN INSTRUMENT USING A HOT KEY (DOWNLOAD)
1)
Turn OFF the instrument.
2)
Insert a pre-programmed HOT-KEY into the 5-PIN connector and then turn the Controller ON.
3)
Automatically the parameter list present into the HOT-KEY will be downloaded into the Controller
memory. The "doL" message will blink during this operation, followed a by a flashing "End" label.
4)
After 10 seconds the instrument will restart working with the new parameters.
Remove the HOT-KEY.
5)
NOTE: the "Err" message is displayed in case of any failed programming operation. In this case, push
again UP button if you want to restart the upload again or remove the HOT-KEY to abort the operation.
XEV23D
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