SRW EWPX 173 User manual

GENERAL DESCRIPTION
EWPX 173/S/E is a digital microprocessor
based device designed to control refriger-
ating units; it is particularly suitable for ap-
plications on “forced air” units operating at
low or normal temperature.
The instrument is provided with three low
voltage outputs to control three auxiliary
relays devoted to users control: compres-
sor, defrost system and evaporator fans.
Relays are installed in the EWDR SLAVE
Din module (version 173), which also pow-
ers the instrument. The module is con-
nected to the instrument through a
MULTIPOLAR CABLE provided with po-
larised, disconnectable telephone connec-
tors at both ends.
The instrument provides two input probes
connected to the Din module for tempera-
ture control and defrost management.
The MULTIPOLAR CABLE conveys the in-
put signals from the NTC probes, the con-
trol signals for the module relays, and the
power supply voltage for EWPX 173/S/E.
EWPX 173/S/E) also includes a RS-485
port for the direct connection to the TELE-
VIS system and to the EWPX ECHO re-
peater, which allows remote display of the
temperature shown on the instrument.
All versions include an internal clock to
control defrosts and a led for alarm sig-
nalling. An internal back up device guaran-
tees time counting also in case of power
failure.
EWPX 173/S/E is available in the two key
front panel 32x74 (ELIWELL standard);
EWDR SLAVE (version 173) is supplied in
the 70x85 (4 modules) format for din rail
(Omega 3) or wall mount.
OPERATION
When operating in the field of refrigeration
the temperature control is performed with
a positive differential; the compressor
stops when the Setpoint temperature is
reached and restarts when the tempera-
ture reaches Setpoint plus the differential.
Two different defrost types can be select-
ed: electrical (the compressor is stopped)
or at cycle inversion (warm gas; the com-
pressor keeps working); it is also possible
to select the interval between defrosts
(and the interval count type; alternatively,
through the clock option up to six different
real times for defrost start can be set), the
stop temperature and a maximum time
(time-out) after which defrost is interrupt-
ed.
The same probe which controls the defrost
cycle is used to control the evaporator
fans; it is possible to set the stop temper-
ature, the delay time after a defrost and the
relation of fans with the compressor and
the micro gate contact.
A series of “safety controls” (delay at start-
up, minimum disable time, minimum time
between activations) protects the com-
pressors from close starts.
In case of probe error or temperature
alarm the instrument signals the event
through the alarm led on the front panel.
The minimum and maximum temperature
alarms can be excluded for a certain time
from start-up and/or after a defrost.
These functions can be customised by
setting some programming parameters.
Other parameters allow to suite the instru-
ment to various applications.
COMMANDS ON FRONT PANEL
The instrument is provided with two keys:
“UP” and “SET/DOWN”.
SET/DOWN: by pressing and releasing it
the Setpoint is displayed, the “SET” led is
turned on.
To change the Setpoint value use the “UP”
and “SET/DOWN” keys within 5 seconds.
If no operation is performed for more than
5 seconds normal mode is restored and
the new value is automatically acquired.
The same button is used to increase val-
ues during Setpoint change or parameters
programming. When held pressed a fast
increase is performed.
UP: button used to increase values. It is
used to change both the Setpoint and the
parameters. When held pressed a fast in-
crease is performed. When held pressed
for more than 7 seconds, this key also al-
lows manual activation of the defrost cycle
(the function is not enabled during
Setpoint or parameter programming).
The “DEFROST” led blinks during manual
defrost.
Led “COMPRESSOR”: led related to the
compressor relay. On when the compres-
sor is operating.
Led “SET”: on during Setpoint setting and
displaying, blinking during parameters pro-
gramming.
Led “DEFROST”: led related to defrost.
On when defrost is in progress, blinking in
case of manual defrost.
Led “ALARM”: on in case of probe alarm
or high/low temperature alarm.
DISPLAYING AND SETTING THE
SETPOINT
To display the Setpoint value press and re-
lease key “SET/DOWN”; the Setpoint is
HOW IT IS MADE
• Housing: plastic resin PC+ABS ex-
tinguishing grade V0
• Size: front panel 76x34 mm, depth
58 mm
• Mount: panel mount on 71x29 mm
hole
• Protection: front IP65
• Connections: telephone connector
for the connection to the EWDR
SLAVE module
• Remote connection: serial con-
nection to the EWPX ECHO re-
peater
• Serial connection: TTL port for the
connection to the EWRS 485 inter-
face for TELEVIS system linking
• Commands: all located on front
panel
• Autonomy for real time clock data:
5 hours approx.
• Outputs: three 12 Vdc/40 mA out-
puts to control the auxiliary relays
in the EWDR SLAVE Din module
(compressor, defrost system and
fans)
• Analogue inputs: two NTC probe
for temperature control and de-
frost management in the EWDR
SLAVE Din module; 1 ON/OFF in-
put for a door switch
• Resolution: 1 °C
• Accuracy: better than 0.5% end of
scale
• Power supply: 12 Vca/cc or 230,
110, 24 Vca (supplied by the
EWDR SLAVE 173)
WHAT IT IS
EWPX 173 is a digital microproces-
sor based device designed to con-
trol refrigerating units; it is
particularly suitable for applications
on “forced air” units operating at
low or normal temperature.
The instrument is provided with
three low voltage outputs to control
three auxiliary relays devoted to
users control: compressor, defrost
system and evaporator fans.
EWPX 173/S/E rel. 6/97 ing
controller for “forced air” refrigerating units with
EWPX ECHO and Televis system outputs

2EWPX 173/S/E 6/97 ing
displayed and the “SET” led turns on.
To change the Setpoint use the “UP” and
“SET/DOWN” keys within 5 seconds.
If no operation is performed for more than
10 seconds normal mode is restored.
MANUAL ACTIVATION OF THE
DEFROST CYCLE
The manual activation of the defrost cycle
is performed by holding the “UP” key
pressed for more than 7 seconds (the key
is not enabled during Setpoint or parame-
ters programming). In case the conditions
are not suitable for defrost (e.g. when the
temperature of the evaporator probe ex-
ceeds the defrost end temperature) the
“dFu” (deFrost unable) label is displayed.
Led “DEFROST” blinks during the manual
defrost cycle.
DISPLAYING PROBE VALUES
The instrument provides two input ports
for probes to regulate the temperature and
control defrost.
By pressing and releasing keys “UP” and
“SET/DOWN” simultaneously, the label
“CPr” (Compressor Probe) is displayed; by
pressing and releasing the “SET/DOWN”
key the display shows the value of the reg-
ulation probe. When the “UP” key is
pressed the label “Epr” (Evaporator Probe)
is displayed; by pressing and releasing key
“SET/DOWN” again the display shows the
value of the defrost probe.
KEYBOARD LOCKING
Through a special programming of the
“Loc” parameter, the keyboard can be dis-
abled to prevent undesired operation or
changes in the instrument settings.
When the keyboard is locked only display
(no changes) is allowed both for Setpoint
and all parameters but the “Loc” parame-
ter to allow keyboard unlock. When the
keyboard is locked no manual activation of
the defrost cycle is permitted.
PASSWORD TO ACCESS
PARAMETERS PROGRAMMING
The instrument allows to set an access
password to enter parameters program-
ming mode.
To set (or change) the password enter pa-
rameter “PAS” and input a value from 1 to
15 (when 0 is input the password is dis-
abled). The password is activated when
the parameters programming phase is
quitted.
In case a password is enabled, when ac-
cess to the parameters programming
phase is requested, the “PAS” label is dis-
played. Press the “SET/DOWN” key to en-
ter password setting, use the “UP” and
“SET/DOWN” keys to change the pass-
word. If the password is correct by press-
ing “SET/DOWN” and then “UP”
programming mode shall be entered, oth-
erwise it shall be automatically quitted.
PARAMETERS PROGRAMMING
Parameters programming mode can be
accessed by holding keys “UP” and
“SET/DOWN” pressed for more than 7
seconds.
The first label is displayed and the “SET”
led keeps blinking as long as parameters
programming mode is enabled.
To access other parameters press “UP” or
“SET/DOWN”.
To display the value of the parameter indi-
cated by the label press “UP” and
"SET/DOWN" simultaneously.
To change its value press “UP” or
“SET/DOWN”. The new values are auto-
matically stored when programming mode
is exited (after no key is pressed for some
seconds).
PROGRAMMING THE REAL TIME
EWPX 173/S includes an internal clock to
control defrosts. To display the real set
time press and release the “UP” (clock)
key: the display will alternatively show
hours (preceded by letter “ h ”) and min-
utes (preceded by “ ' ”).
To change the time, press and release the
“UP” (clock) key, then hold the
“SET/DOWN” key pressed for about 7
seconds; when the hours or the minutes
are displayed (press the keys simultane-
ously to skip from one display mode to the
other), use the “UP” and “SET/DOWN”
keys to set the required value.
The new values are automatically stored
exiting the programming mode, after no
key is pressed for about 10 seconds.
EWPX 173/S includes an internal back-up
device which allows time counting also in
case of power failure. The autonomy is
about 5 hours, after which the real time
memory is lost and shall be reprogrammed
(in such case the count restarts from
“h00”-“00'” at power up).
The loss of the memory information is
shown at restart after a power failure only
when the clock option is enabled (see pa-
rameter “dit”) by displaying label “dte” (de-
frost time error) and the room value
alternatively.
PARAMETERS DESCRIPTION
diF: diFferential.
Setpoint intervention differential.
For applications in the field of refrigeration
the differential shall be set to positive val-
ues: the compressor stops when the
Setpoint is reached (according to data de-
tected by the regulation probe) and
restarts when the temperature reaches
Setpoint plus the differential.
LSE: Lower SEt.
Minimum value allowed for Setpoint.
Usually set to the minimum value that can
be measured by the probe.
HSE: Higher SEt.
Maximum value allowed for Setpoint.
dty: defrost type.
Type of defrost.
EL = Electrical defrost;
in = inversion cycle defrost (warm gas).
dit: defrost interval time.
Defrost interval time in hours.
dct: defrost counting type.
Counting mode for the defrost interval.
dF = digifrost Feature (DIGIFROST®
method; only the operation time of the
compressor is counted;
rt = real time (the instrument operation time
is counted);
SC = Stop Compressor (defrost is per-
formed whenever the compressor stops);
Fr = Free (the compressor relay is freed
from defrost functions, thus continuing to
regulate according to the Setpoint).
dt1…dt6: defrost time 1…6.
Parameters to set the time (real) for defrost
starts (accessible only when “dit” is set to
0).
0…23 = real hours; oF = oFF (disabled).
Note: it is not necessary to input parame-
ters’ values (dt1…dt6) in the exact time se-
quence.
doh: defrost offset hour.
Delay time for defrost start; in minutes.
dEt: defrost Endurance time.
Defrost time-out; in minutes.
dSt: defrost Stop temperature.
Temperature causing defrost end.
FSt: Fan Stop temperature.
Fan stop temperature; a value read by the
defrost probe exceeding the set value
causes fans to stop.
Fdt: Fan delay time.
Delay time for fans activation after a de-
frost; in minutes.
dt: drainage time.
Dripping time; in minutes.
dPo: defrost (at) Power-on.
Defrost at power on.
y = yes; n = no.
ddL: defrost display Lock.
Display lock during defrost.
n = no; during defrost the display shows
the value read by the room probe.
y = yes; during defrost the display shows
the last value read before defrost by the
room probe.
Lb = Label (“defrost”); during defrost the
display shows label “dEF” (dEFrost) , indi-
cating defrost is in progress.
Lg = Label (“dégivrage”); during defrost the
display shows the label “dEg”
(“dEgivrage”), indicating defrost in
progress.
NOTE: in case “y”, “Lb” or “Lg” are select-
ed the display will be locked until the
Setpoint temperature is reached in the
room probe.
dFd: defrost Fan disable.
Allows to select or deselect the exclusion
of evaporator fans during defrost.
n = no; y = yes.
Att: Alarm temperature type.
Interpretation mode for parameters “HAL”
and “LAL”.
Ab = absolute;
re = relative (referred to Set).
HAL: High ALarm.
Maximum temperature alarm. When this

3EWPX 173/S/E 6/97 ing
value is exceeded the Televis alarm signal
is triggered.
LAL: Low ALarm.
Minimum temperature alarm. When the
temperature is below this value the Televis
alarm signal is triggered.
AFd: Alarm (Fan) differential.
Operating differential for temperature
alarms.
PAO: Power-on Alarm Override.
Alarm exclusion after instrument power on;
in hours.
dAo: defrost Alarm override.
Temperature alarm exclusion after defrost;
in minutes.
oAo: output (door) Alarm override.
Exclusion time for temperature alarms after
the door is opened; in hours.
tAo: temperature Alarm override.
Temperature alarm signal delay; in min-
utes.
Fco: Fan compressor on.
Allows to select or deselect fan stop when
the compressor is OFF.
oF = yes; on = no.
Fod: Fan off (with opened) door.
Allows to select or deselect the fan block
when the door is opened.
oF = yes; on = no.
cPP: compressor Probe Protection.
Allows the selection of the compressor
state in case of faulty probe.
oF = relay OFF for faulty probe.
on = relay ON for faulty probe.
dc = duty cycle; the ON and OFF times of
the relay are set by parameters “Ont” and
“OFt”.
Ont: On time (compressor).
ON time for the compressor (when CPP =
dc); in minutes.
OFt: OFF time (compressor).
OFF time for the compressor (when CPP =
dc); in minutes.
ctP: compressor type Protection.
Allows to select the protection type against
close starts of the compressor the time is
set through the following parameter).
nP = no Protection.
don = delay on start. Delay in the activation
of the relay.
doF = delay at switching oFf. Minimum
time for delay switching off.
dbi = delay between two successive
starts. Minimum time between two subse-
quent relay starts.
cdP: compressor delay Protection.
Time referred to the previous parameter; in
minutes.
odo: output delay (at) on.
Output activation delay after instrument
power on; in minutes.
dod: disable (with) opened door.
Allows to select or deselect the option to
turn users (compressor and evaporator
fans) off when the door is open.
n = no; y = yes.
PrP: Presence Probe.
Allows to select the presence of the
Evaporator probe.
nP = Evaporator probe not present;
EP = Evaporator probe present;
AP = not usable;
EAP = not usable.
CAL: CALibration.
Allows calibration of the displayed value
(measured by the display probe) in case it
is different from a known value. Usually set
to “0”.
dEA: dEvice Address.
Allows to select the device address within
a remote control network.
FAA: FAmily Address.
Allows to select the device family within a
remote control network.
diP: door input Polarity.
Allows to select polarity for the micro-door
input.
OP = open; CL = closed.
DEFAULT SETTINGS - STANDARD MODELS
Parameter
diF
LSE
HSE
dty
dit
dct
dt1…dt6
doh
dEt
dSt
FSt
Fdt
dt
dPo
ddL
dFd
Att
HAL
LAL
AFd
PAO
dAo
oAo
tAo
Fco
Fod
cPP
Ont
OFt
ctP
cdP
odo
dod
PrP
CAL
dEA
FAA
diP
CLO
Loc
PAS
rEL
Hdc
tAb
Description
diFferential
Lower SEt
Higher SEt
defrost type
defrost interval time
defrost counting type
defrost time 1…6
defrost offset hour
defrost Endurance time
defrost Stop temperature
Fan Stop temperature
Fan delay time
drainage time
defrost (at) Power-on
defrost display Lock
defrost Fan disable
Alarm temperature type
High ALarm
Low ALarm
Alarm (Fan) differential
Power-on Alarm Override
defrost Alarm override
output Alarm override
temperat. Alarm override
Fan compressor off
Fan off door
compressor Probe Prot.
On time (compressor)
OFF time (compressor)
compr. type Protection
compr. delay Protection
output delay (at) on
disable opened door
Presence Probe
CALibration
dEvice Address
FAmily Address
door input Polarity
CLOck frequency
(keyboard) Lock
PASsword
rELease firmware
Hardware code
tAble of parameters
Range
–12…12
–999…HSE
LSE…999
EL / in
0…31
dF / rt / SC / Fr
0…23 / oF
0…59
1…250
–999…999
–999…999
0…250
0…250
n / y
n / y / Lb / Lg
n / y
Ab / re
–999…999
–999…999
1…50
0…10
0…999
0…10
0…250
oF / on
oF / on
oF / on / dc
0…250
0…250
nP/don/doF/dbi
0…15
0…99
n / y
nP / EP / AP / EAP
–12…12
0…14
0…14
OP / CL
/
n / y
0…15
/
/
/
Unit
°C / °F
°C / °F
°C / °F
flag
hours
flag
ore / flag
minutes
minutes
°C / °F
°C / °F
minutes
minutes
flag
flag
flag
flag
°C / °F
°C / °F
°C / °F
hours
minutes
hours
minutes
flag
flag
flag
minutes
minutes
flag
minutes
minutes
flag
flag
°C / °F
number
number
flag
Hertz
flag
number
/
/
/
Default
2
–50
40
EL
6
dF
0
0
30
8
2
0
0
n
n
y
re
50
-50
2
2
60
10
0
oF
oF
on
10
10
doF
0
0
n
EP
0
0
0
OP
/
n
0
/
/
/

4EWPX 173/S/E 6/97 ing
CLO: CLOck frequency.
Reading double the mains frequency.
Loc: keyboard Lock.
Allows to disable keyboard operation to
prevent undesired operation or changes in
the instrument settings.
When the keyboard is locked only display
(no changes) is allowed both for Setpoint
and all parameters but the “Loc” parame-
ter to allow keyboard unlock.
y = yes; n = no.
PAS: PASsword.
Allows to select the password value (refer
to section “Password to access parame-
ters programming”).
0 = no password is required to enter para-
meters programming.
1…15 = values allowed for the password.
rEL: rELease firmware.
Read only parameter showing the release
code of the device.
Hdc: Hardware code.
Configuration index for factory set parame-
ters; cannot be changed by the user.
tAb: tAble of parameters.
Configuration index for factory set parame-
ters; cannot be changed by the user.
MECHANICAL MOUNT
EWPX 173/S/E is designed for panel
mount. Drill a 29x71 mm hole and intro-
duce the instrument, then fix it with the
special bracket (included).
The EWDR SLAVE module (version 173) is
designed for wall (extractable brackets) or
Din rail (Omega 3) mount.
The operating temperature range for cor-
rect operation is from –5 to 65 °C. Do not
install the instrument in moist and/or dirty
places; it is suitable for operation in envi-
ronments with an ordinary pollution level.
Leave enough room for air circulation by
the cooling holes of the instrument.
ELECTRICAL CONNECTIONS
EWPX 173/S/E is provided with a tele-
phone connector for the connection to the
Din module, a serial output for the connec-
tion to the Televis system (through the RS-
485 port), a serial output for the EWPX
ECHO remote repeater, and screw terminal
blocks for the connection of electrical ca-
bles with a maximum section of 2.5 mm2
(one wire only per terminal in compliance
with VDE regulations) for other connec-
tions.
EWDR SLAVE (versions 173) includes, be-
side a telephone connector for the con-
nection to EWPX 173/S/E, a screw
terminal block for the connection of electri-
cal cables with a maximum 2.5 mm2sec-
tion (one wire only for each block,
according to VDE regulations). Relay out-
puts are free from voltage.
The MULTIPOLAR CABLE connection be-
tween the EWPX 173/S/E and the Din
module shall be installed before powering
the system.
The EWDR SLAVE is provided with three
relay outputs: compressor, fan and defrost
system. Do not exceed the maximum con-
tact capacity: 15(6)A 250V AC for the
compressor, 8(3)A 250V AC for the defrost
system and fans. In case of heavier loads
use a suitable contactor.
Check the power voltage for the EWDR
SLAVE complies with requirements.
The two NTC probes have no insertion
polarity and can be lengthened using a
common bipolar cable (bearing in mind
that very long probes imply worse instru-
ment performances referred to the EMC
electromagnetic compatibility).
Outputs for the connection of the EWPX
ECHO repeater module require connec-
tions according to the indicated polarity.
The probe cables, the connection cables
for the EWPX ECHO, for the RS-485 port
and the MULTIPOLAR CABLE shall be
kept far from the relay cables both for EMC
and safety reasons.
The coordinated European safety regula-
tions state that the relay contacts (and
generally speaking, all parts subject to
dangerous voltage) shall be kept away
from the very low safety voltage connec-
tions (probe, RS-485, MULTIPOLAR CA-
BLE) using insulation systems and
distances providing at least a double or re-
inforced insulation.
However EMC requirements for correct
operation suggest/impose better accuracy
in such separation by using separated in-
sulating pipes and special cable fixing sys-
tems.
EWPX ECHO operates at very low safety
voltage and shall be installed respecting
the same conditions of insulation/separa-
tion from the powered components and
the relay contacts.
ERROR MESSAGES
Error message “dte” (defrost time Error) is
displayed in case the datum for the real
time is lost (see section “programming the
real time”).
Moreover EWPX 173/S/E displays error
message “E1” in case of shorted, inter-
rupted or disconnected probe. The mes-
sage is also displayed in case of “under
173 version
EWDR SLAVE
module
10 11 12
defrost
NTC probe
thermostat
NTC probe
defrost fan
comp.
POWER SUPPLY
14 15 16 17 18 19 20 21 22 23 24
door
switch
+
–
gnd
RS-485
EWPX 173/S/E
4 5 1 2 3
output to
the EWPX ECHO
signal repeater
–+
CONNECTIONS

5EWPX 173/S/E 6/97 ing
range”, i.e. when the lower display limit
(–55 °C) is exceeded, or in case of “over
range”, i.e. when the upper display limit
(125 °C) is exceeded.
Error message “E2” refers to the evapora-
tor probe (defrost end) for the same rea-
sons as above.
In case of error the Televis system alarm is
immediately activated.
Before replacing the probe check its con-
nections.
EWPX 173/S/E TECHNICAL DATA
Housing: plastic resin PC+ABS extin-
guishing grade V0.
Size: front panel 76x34 mm, depth
58 mm.
Mount: panel mount on 71x29 mm hole.
Protection: front IP65.
Connections: telephone connector for
the connection to the EWDR SLAVE mod-
ule (versions 173), screw terminal block for
wires with a maximum 2.5 mm2diameter
(one wire only per terminal in compliance
with VDE regulations) for other connec-
tions.
Remote connection: serial connection to
the EWPX ECHO repeater.
Serial connection: RS-485 port for the
connection to the TELEVIS system.
Display: on 3 digit display (digit height
12.5 mm).
Commands: all located on front panel.
Data storage: on non-volatile memory
(EEPROM).
Autonomy for real time clock data: 6
hours approx.
Operating temperature: –5…65 °C;
(23…149 °F).
Storage temperature: –30…75 °C;
(–22…167 °F).
Outputs: three low voltage outputs to
control the auxiliary relays in the EWDR
SLAVE Din module (compressor, defrost
system and fans).
Analogue inputs: two NTC probe for
temperature control and defrost manage-
ment (in the EWDR SLAVE Din module).
Digital input: 1 ON/OFF input for a door
switch.
Range: –50…100 °C (–58…212 °F).
Resolution: 1 °C.
Accuracy: better than 0,5% end of scale.
EWDR SLAVE 173 TECHNICAL DATA
Housing: ABS plastic; V0 extinguish
grade.
Size: 70x85 mm Din modules, depth
61 mm.
Mount: on Din (Omega 3) rail or wall.
Connections: telephone connector for
the connection with EWPX 173/S/E, screw
terminal blocks for wires max 2.5 mm2for
other connections (one wire only per con-
tact and grounded Din rail in compliance
with VDE regulations).
Operating temperature: –5…65 °C;
(23…149 °F).
Storage temperature: –30…75 °C;
(–22…167 °F).
Outputs: 2 outputs on N.O. relays for
compressor 15(6)A 250V AC and fans
10(4)A 250V AC, 1 output exchange relay
10(4)A 250V AC for defrost system.
Analogue inputs: two NTC probe for
temperature control and defrost manage-
ment.
Consumption: 8 VA max.
Power supply (according to model):
12 Vca/cc ±15%; 220 110, 24 Vca ±10%.
Others on request.
Eliwell S.p.A.
via dell’Artigianato, 65
Zona Industriale
32010 Pieve d’Alpago (BL)
Italy
Telephone [phone]
Facsimile [phone]
A Siebe Group Company