GENERAL DESCRIPTION
EWPX 193(/E) is a single point temperature
controller designed for applications in the
field of commercial refrigeration.
The instrument provides three input
probes for temperature control, defrost
control for the first and the second evapo-
rator. Four relay outputs are provided for
the compressor, the defrost systems of the
first and second evaporator, and the evap-
orator fans.
As a standard feature it can be connected
to the TELEVIS system (through its appro-
priate interface module). The “/E” version
can also be connected to the EWPX
ECHO data repeater, which allows remote
display of the temperature measured by
the instrument.
The instrument can be configured accord-
ing to the application through a series of
parameters - it is supplied in the new
32x74 mm cabinet (ELIWELL Standard).
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 for value increase, used
to change both the Setpoint and the para-
meters. A fast increase is obtained by
holding it pressed.
This key also allows manual start of the de-
frost cycle, by holding it pressed for more
than 5 seconds (this function is not en-
abled during Setpoint or parameter pro-
gramming; please refer to paragraph
“Controlling Defrost”.
During the manual defrost cycle the “DE-
FROST” led will blink.
“COMPRESSOR” Led
: led related to the
compressor relay; it is on when the com-
pressor works.
“SET” Led
: it is on during Setpoint display
and programming; it blinks during parame-
ter programming.
“DEF” Led
: status light of the defrost. It is
on during automatic defrost; it blinks dur-
ing manual defrost.
“ALARM” Led
: led related to the alarm. It
is on when the alarm is active or disabled
due to the exclusion time (see parameters
“PAO”, “dAo” and “tAo”); it blinks when the
alarm is silenced.
DISPLAYING AND SETTING THE
SETPOINT
To display the Setpoint value press and re-
lease “SET/DOWN”; the Setpoint value is
displayed and the “SET” led is turned on.
To change the Setpoint value operate on
keys “UP” and “SET/DOWN” within 7 sec-
onds; after such time normal mode will be
restored.
CONTROLLING DEFROST
The instrument can control defrost in two
different evaporators. The trigger call to the
defrost outputs is simultaneous both in
case of manual control and in case of in-
terval end. To enable the outputs the tem-
perature detected by the probe on each
evaporator shall be below its defrost end
temperature (parameters “dSt” and
“AAS”); therefore defrost may take place in
one evaporator only.
Output disable is related to the end defrost
temperature on each probe, therefore may
be not simultaneous.
Defrost is considered over (the defrost in-
terval starts and the dripping begins, etc.)
when both outputs are disabled.
MANUAL ACTIVATION OF THE
DEFROST CYCLE
The manual activation of the defrost cycle
starts by holding the “UP” key pressed for
more than 7 seconds (the key is not active
during Setpoint or parameter program-
ming). In case the conditions for defrost
are not suitable in both evaporators (e.g.
the temperature of both the evaporator
probes exceeds the end defrost tempera-
ture), the blinking label “dFu” (defrost un-
able) will be displayed.
During manual defrost the “DEFROST” led
blinks.
SILENCING THE ALARM
An alarm condition is signalled by the
“ALARM” led.
The alarm can be silenced by pressing any
key on the front panel; the led will blink un-
til the end of the alarm condition.
DISPLAYING PROBE VALUES
The instrument provides two probe inputs:
temperature control and defrost manage-
ment.
The pressure and release of the “UP” and
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: on screw terminal
block for wires max 2.5 mm
2
(one
wire only per block in compliance
with VDE regulations)
• Remote connection: serial con-
nection to the EWPX ECHO re-
peater (version /E only)
• Serial connection: TTL port for the
connection to the EWRS 485 inter-
face for TELEVIS system linking
• Display: 3 digit plus “-” sign; digit
height 12.5 mm
• Main outputs: 1 on N.O. 8(3)A
250V AC relay for the compressor,
2 on N.O. 5(2)A 250V AC relay for
the fans and defrost system of the
first evaporator
• Second evaporator output: 1 out-
put on N.O. 8(3)A 250V AC relay
• Analogue inputs: three NTC
probes for temperature control
and defrost management (first
evaporator and second evapora-
tor)
• Resolution: 1 °C, 0.1 °C, or 0.5 °C,
selectable through parameters
• Consumption: 3VA (5 VA in the
“/E” version with the EWPX ECHO
module connected)
• Power supply: 12 Vac/dc ±15%
WHAT IT IS
EWPX 193(/E) is a single point tem-
perature controller designed for ap-
plications in the field of commercial
refrigeration.
The instrument provides three input
probes for temperature control, de-
frost control for the first and the
second evaporator.
Four relay outputs are provided for
the compressor, the defrost sys-
tems of the first and second evapo-
rator, and the evaporator fans.
EWPX 193(/E)
rel. 11/97 ing
controller for refrigerating units
with double evaporator
